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JOpera User Manual - JOpera for Eclipse

1. opera Process Support for Web Services The JOpera Manual v2 4 3 March 1st 2009 http www jopera org info jopera org C 1999 2009 Cesare Pautasso il Contents 1 Introduction 1 1 What is JOpera for Eclipse cnrs ber isiin i tedd 1 2 What s new in JOpera for Eclipse LL 1 3 About JOpera for Eclipse 2 Li ADDETTO iui ae N rr daa AAA RIERA AR 2 Getting Started 24 JOAN nw eGR RARE ERE AA 2 1 1 System Requirements oaa 2 2 Running JOpera for Eclipse LL Bee nn ke A ee See ee eee ee ae ee E ee we ae e RS oa wee ew Ee ew 2 4 1 Service Composition with Processes 2 4 2 Design Time User Interface e 2 4 3 Compiling Processes u u wu une 0 an a aaa a 2 4 4 Deploying Processes e 2 4 5 Running Processes 6 o osas 2 4 6 Monitoring Processes 200 ew ed e n 20 PA iii KREGER EERE EE Ri I Tutorials 3 Hello World Tutorial 3 1 Creating a new Project un nn ORE ee ww 3 2 Creating a new OML file 3 3 Setting up the Hallo World Program mm nenn 3 4 Running the Program with a test Process 3 5 Checking the Results su a A A A 4 Web Services Tutorial 4 1 Web Services Tutorial Overview 2 oo a 42 Creating anew Project 1 446 ew eee eee EEE a A 43 Importing a WSDL File sissi REESE de SEE Ewe ahnen 4 4 Creating a new Process iii e erro Ass 4 5 Adding Input Output Parameters aooaa 4 6 Populati
2. Advanced System Parameters shell mode Overview Program Notepad 1 0 Adapter Windows UNIX Adapter Mac UNDOD Figure 12 4 The UNIX adapter input parameters displayed in the adapter editor tab Enumerated Parameter Types Enum a b c rendered with a combo box initialized using the a b c el ements Boolean equivalent to Enum true false Note Enumerated types are only used to suggest to the user a set of possible values The actual values entered by the users are currently not checked at design time to be restricted to the enumerated elements Thus using Enum types does not remove the need for input validation at run time by the subsystem adapter Types with syntax highlighting XML a multi line editor with XML Syntax highlighting Code Java an editor used for Java snippets Java syntax highlight ing not yet implemented Type Tags Advanced As shown in the previous examples tagging parameter types with Advanced will display the corresponding parame ter in the Advanced System Parameters section This should be used only for optional parameters for which a reason able default can be automatically provided by the Adapter since version 2 4 3 12 6 The ISubSystem Interface This interface must be implemented by all service invocation plugins It contains only two methods 89 12 HOW TO WRITE SERVICE INVOCATION PLUGINS Adapter HTTPAdapter HTTP een body Body of the HTTP POST PUT Request System Par
3. multiplication snippet A variable of type float will be declared automatically by the JOpera compiler Overview Program Multiply 1 0 Figure 6 1 Setting up the multiply program interface e Enter two values for the a b parameters in the run configuration Figure 6 5 e Click on Run to start the process e JOpera will switch to the Monitor perspective and you can check the results of the process Figure 6 6 You can find a solution for this tutorial in example file called tutorial_snippet oml As an exercise try to replace the existing snippet with another one doing a division What happens if you run the process passing a 0 value 6 2 Java Methods 6 2 1 Importing Java Classes 6 2 2 Calling Java Static Methods 6 3 Java Objects 6 3 1 Working with Objects as parameters 30 6 3 JAVA OBJECTS 37 Adapters Search Text JAVA Matching Items 152 JAVA METHOD 22 JAVA SNIPPET Figure 6 2 Select the Java Snippet Component Type result a b a float b float result float A The Script contains any Java code that fits inside a Java method Program Multiply 1 0 Adapter JAVA_SNIPPETAdapter JAVA SNIPPET Figure 6 3 Enter the snippet in the adapter configuration Overview Processes Programs TE Test_Multiply 1 0 Multiply 1 0 Overview Program Multiply 1
4. 50 8 4 How to Report a Bug Liar de ea A a 51 JOpera Visual Composition Language Reference 53 O1 Poser aisha Le Rn 53 1 11 Empty Pine au ne ie a a a LR en 53 Li OUN e aae eee Ree AAA 53 SI I RR LA 53 NE E obec hehe eee E E ee en ee 54 9 2 Branching Control Flow Patterns 54 Dl Po pIE i Era EEE ES EE GS 54 022 Syichronzation isaac wee A oe ee a hr ne 54 92 3 Dimple Merge gk bee ee ee A ew i 55 9 2 4 Exclusive Choice 1 nn 55 9 2 5 Multiple Choice Lib RS LE 55 9 2 6 Synchronizing Merge 55 Ot Mid ela lla RRR e ae 55 9265 Nouto dot 22 4 24 ASTRO 55 be iii 55 dol a loan i AREAS LL 55 E Oe ERE eR eee eee Yeh Se EEE 56 Moe AI lt a o AAA E Eee 97 9 3 4 For each l00p oococorns 64 44S erase a 57 9 4 Data Flow Patterns 2 282228 en a 58 TE M e aLe beni 98 Aa Se oh ee nennen LL 58 943 Global She iii RE SEER EASE EDGE ERR ERE ESS eS 58 Contents 9 5 gad FUP ae ERRATE ER AR A E y e i 9 4 5 Generic Data Transformation Advanced Patterns Jol o iii A a a ROLE SEES OS e Di i 0 5 3 Dynamic Late Binding lt esses srid a ea 9 5 4 Asynchronous Cancellation LL 9 5 5 Synchronous to asynchronous Mapping 2 2 2 a a eee 10 Feature Reference 10 1 10 2 WSDL Import RE EEE AA 10 1 1 The WSDL File and import Options LL 10 1 2 Selecting the Operations HK m ee 10 1 3 Warnings Errors and Interpretations 0 0 000 eee eee 10 14 Known Linens sirio La E HER ESS a a SS Autoconnect
5. FactorialRecursiveProcess 1 0 Stable 8 Cesare Pautasso y Programs 9 lineage Double 1 0 Stable 22 This program returns twice lineage Inc 1 0 Stable 22 This program increments it loan CreditRatingService 1 0 Stable z Cesare Pautasso loan DecisionLogic 1 0 Stable 1 Cesare Pautasso loan RejectApplication 1 0 Stable 1 Cesare Pautasso loan StarLoan 1 0 Stable 1 Cesare Pautasso Figure 11 9 The lineage summary When an entity is double clicked the second view the instance browser shows up listing its in stances When the refresh icon on the right of the task bar is pressed as seen in Figure 11 10 the list gets fetched again from the database The refresh function is also accessible from the context menu gy o Figure 11 10 The refresh icon 11 4 3 Instance Browser The instance browser lists the instances of a certain entity logged in the database In this view attributes like the input and output parameters along with the execution time and various execution timestamps can be examined Figure 11 11 shows the instance browser A search among the available instances can be performed using the search panel It can be chosen as seen in Figure 11 12 if we want to find tuples with an attribute containing starting ending or exactly equal to the value entered in the text field All instances that have any attribute matching the search pattern is then retrieved 19 nstance id in al 11 123 23 23 23 23 2
6. Figure 4 8 Executing the Sample Process ESSO INERTI CE AC ES Ox0per gt A TemperatureService oml X i zip return Figure 4 9 Switching to Monitor Mode 4 9 EXECUTING AND MONITORING THE PROCESS A Temperatureservice oml X getTemperature getlemp getlemper ture Overview Process getTemperature Views ControlFlow View DataFlow Figure 4 10 Monitoring a Running Process getlemperature Temperatureservice oml X getlemperature Overview Process getTemperature view ControlFlovs view DataFlow Figure 4 11 Successfully finished Process 29 30 4 WEB SERVICES TUTORIAL E Properties X S EN Activator Condition Description Mame Program Input Parameters zipcode Output Parameters return System Input Parameters AM getTemp Operation getTemp Port TemperaturePort Service Temperatureservice SO amp PInput lt soapEnv Envelope mlns soapenv http schemas xmisoap orgisoaplenvelo WSDL http aww methods neti sd 2001 Temperatureservice wsdl System Output Parameters errormsg SOAP Output getTemp getTemp 47906 25 0 lt xml version 1 0 encoding UTF 8 gt lt S0AP ENV Envelope mins SO0AP status System Parameters ENDET HOST MAME PROGNAME READYDT RESTART STAR TOT STATE TYPE WALL 2004 12 15 16 49 25 966 172 30 59 36 getTemp getTemp 2004 12 15 16 49 24 325 0 2004 12 15 16 99
7. type filter text im General JOpera Editor Settings PAM Adapters Editor Color Settings Help gt Install Update Text z b Java en w JOpera JOpera Variable MM Editor o Editor Sticky XML Tag C e Monitor o m Plug in Developme XML Attribute E Run Debug b Team WOLips Settings for AutoConnection Feature Connect Hidden Parameters _ Ignore Connected Parameters Figure 10 5 Preferences Dialog 63 10 FEATURE REFERENCE type filter tex iw JOpera b General Common JOpera Settings Ant 4 Hel M Show Type and Default Value in Outlines elp p Install Update __ Show Component Types Java y JOpera r Graph Editor Settings Editor Show Parameter Types Editor Stick Ll Show Program Nam Monitor Show Icon ha Plug in Develop Run Debug Animate Layout it Figure 10 6 Preferences Dialog 10 3 Refactoring 10 3 1 Upgrade replacement of programs and processes JOpera supports the replacement of service interfaces e g when a service is upgraded to a new version with small modifications The feature is accessible through the context refactor submenu Figure Figure 10 9 The Program Process Browser Figure Figure 10 10 assists the user in choosing the new pro gram process interface The user may choose in the wizard Figure Figure 10 11 if only the selected occurences or all matching ones ar
8. 9 5 4 Asynchronous Cancellation 9 5 5 Synchronous to asynchronous Mapping 98 10 Feature Reference This chapter contains reference information about the most important features of JOpera 10 1 WSDL Import Wizard The WSDL Import Wizard gives the user the possibility to customize the generated OML file This section will explain in depth the different options and what they generate It also explain what are the limitation of the importer as not every WSDL file can be imported successfully 10 1 1 The WSDL File and import Options new Import WSDL Import WSDL into JOpera This wizard imports a Web Service described by a WSDL document into JOpera Container URL or File tto iiey methods net sd 2001 Temperatureservice wsdl Target OML File GM eE ecc Connection Type Input Format Output Format 504P 1 1 Ey Leaves only Leaves Only soar 1 2 With Packer With Unpacker HTTP Get _ HTTP Post Figure 10 1 Basic parameters and import options The first page of the Import Wizard is used to define the basic parameters needed to import a WSDL File The different input parameters are e Container The Container is the destination project to store the generated OML file The Project can also be selected with the Browse Button situated to the right of the entry field e URL or File This is where the input WSDL file path has to be entered The Format of the path has to be a complete URL meaning with
9. Published true SSS o Subprocess false E Input Parameters Sa I E Output Parameters te allo World HO O Figure 3 10 Check the results of the process in the JOpera Monitor perspective 1 Look in the Properties view for the values of the output parameters 2 Use the Instance Navigator view to manage the processes that are currently running Note Try to start more processes and see what happens 22 4 Web Services Tutorial In this tutorial you will learn how to use JOpera to call a single Web Service 4 1 Web Services Tutorial Overview In order to compose this simple one service process in JOpera for Eclipse the following steps need to be completed 1 i 3 A new JOpera Project needs to be created The WSDL description of the Web Service needs to be imported A new process needs to be defined and input and output parameters need to be added A program resulting from the WSDL import needs to be added to the process The data flow connections need to be drawn The process then needs to be compiled by saving it and run Finally the execution of the process needs to be monitored 4 2 Creating a new Project In order to create a new Project right click in the JOpera Navigator i Py Project ar Ju Opera Project Fab pi RJO OML File Eag Import P Example e Export Fey other Ctrl N Refresh Figure 4 1 Creating a new JOpera project and select
10. ajax_gmap oml ecommerce oml Web Services Examples ws_quiz oml ws_eliza oml Mashup Examples yahoo oml Example used in Section 3 on page 17 Example showing how to write a recursive process Classical Loan Processing example Center a Google Map at the given address Classical Customer Supplier Shipment Warehouse exam ple featuring asynchronous interactions Note These examples may not always work due to the age of the Web services employed If you find a suitable replacement Web service let us know Example showing how to call a Trivial Quiz Web Service Example showing two different ways to make an Eliza Web Service chat with herself Show Yahoo Local search results on a Google map 13 2 GETTING STARTED Component Type Examples echo oml Example for the ECHO component type bpel_example oml Example for the BPEL component type using the lib bpel library msg_example_asynch oml Example for the MSG component type showing a complex e business asynchronous interaction where a client interacts with a set of suppliers through a broker composite process msg_example_cs oml Example for the MSG component type showing a simple asynchronous interaction pattern between a client and a server process notepad oml Example for the UNIX component type showing how to run the notepad exe Windows application from a process ssh_date oml Example to run the date command through a remote SSH connection
11. called value in this example does not exceed a certain threshold called to starting from an initial value called from while being incremented by an increment called increment every iteration the data flow looks as follows Figure 9 5 Data flow of an example while loop 56 9 3 LOOPS The parameters to increment and from are passed as input parameters to the process The parameter value is initially set to from meaning that counting starts with the initial value from The parameter value is an input parameter of the Task JSCounter and is used to keep track of the number of iterations already executed The Task JSCounter therefore adds the value of increment to the previous value and copies the result in its output parameter result which is in turn copied in the input parameter value After the value value has been updated the body of the loop is executed In this simple case this means that the task BPELWait is executed As long as the value iof the parameter value remains smaller than the parameter to JSCounter and BPELWait will be executed in turn as is also depicted in Figure 9 6 _ aa Figure 9 6 COntrol flow of an example while loop The following OML excerpt shows both the activators and conditions of the two tasks of this process lt ACTIVITY OID Activity40 NAME BPELWait DESC ACT Finished JS
12. 0 Adapter JAVA_SNIPPETAdapter AVASNIPPET Figure 6 4 Create a test process for the snippet 38 6 JAVA SERVICES TUTORIAL Create manage and run configurations w Fex E gt ws multiply Test_Multiply 1 0 Multiply w JOpera Process Arguments E Start Options D Common p ws multiply Test_Multiply 1 0 Process Name ws multiply Test_Multiply 1 0 Input Parameters Vale float 33 float 10 98 Apply Revert Filter matched of 54 items Cam Figure 6 5 Enter the input parameter values to test the Java snippet W Instance Navigator E o Abstract Di TE 1 0 1 1 a Description Name Test_Multiply Published true Subprocess false w Input Parameters a 10 98 HTest_Multiply b A Output Parameters ose 3 result Test_Multiply ControlFlow Oataflowf O Figure 6 6 Check the results of the test in the Monitor Part Il Reference Manual 39 7 Frequently Asked Questions This chapter answers the most frequently asked questions about JOpera If you have a question that is not answered in this FAQ consider reading the rest of the Documentation before you send us an email 7 1 General Questions What is JOpera JOpera is an autonomic process support system targeted for generic service composition What do I need to run JOpera JOpera runs on Eclipse 3 3 3 4 with Java JDK 1 5 and requires the GEF plugin What is new in JOpera for Eclipse A lot S
13. 24 325 4 ACTY 1 64 Figure 4 12 Properties of a Finished Task Tip to display all of these properties you should press the Advanced button in the view s toolbar Ji kernel Memory Inspector Refresh Value temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter temp_converter lt a O o O O o O O o O O 0 O O o O o O O Input Qutpuk System System System System System System System Input Qutput System System System System System System System System celsius Fahrenheit CALLER delete_on_finish ENDET REACYDT STARTOT STATE WALL temp return ENDET HOST MAME PROGNAME READYOT STARTET STATE TYPE 23 73 Flo 2004 11 16 23 27 34 058 2004 11 16 23 27 32 906 2004 11 16 23 27 32 906 1 152 23 T3 2004 11 16 23 27 34 000 192 160 0 2 Chor tor 2004 11 16 23127132 906 2004 11 16 232732 906 ACTY Figure 4 13 Monitoring the Sample Process in the Kernel Memory Inspector 5 Monitoring Widget Tutorial This tutorial will explain how to configure the Web Monitoring Widget 5 1 Introduction The Monitoring Widget is a simple Web based tool that allows the monitoring of the processes running on a remote server from a common Web br
14. 3 LOOPS 9 2 3 Simple Merge A point in the process where two or more exclusively alternative branches come together without synchronization Use the choice process parameter A B to control which of the two initial tasks A xor B will be executed Since by definition only A xor B can run the activator in C can be safely set to Finished A OR Finished B For scenarios where this assumption does not hold A or B have a look at the MultiMerge and the Discriminator examples 9 2 4 Exclusive Choice A point in the process where one out of several branches is chosen To choose which task B or C is executed set the choice input parameter of the process to the corresponding task name Look at the conditions associated with the two tasks to see how this works 9 2 5 Multiple Choice A point in the process where a number of branches can be chosen Considering the conditions associated with the B and C tasks it is possible to run either B C or both by setting the appropriate value B C BC into the choice input parameter of the process 9 2 6 Synchronizing Merge This process will synchronize at task D two alternative paths task B or task C that can both be taken at the same time but also taken as alternatives To control which of B or C or both is taken set the choice process input parameter to one of the following values B C BC 9 2 7 Multiple Merge Branches converge without synchronization If more than one b
15. The former is performed automatically during process execution and the latter is done using four main components 18 11 4 LINEAGE TRACKING e The lineage summary this view shows the entities logged in the database It shows various of their attributes and enables to choose one of them and go to the instance browser e The instance browser this view shows a list of instances from an entity along with a certain number of relevant parameters it is possible to choose an instance and view it in the next component the lineage browser e The lineage browser this is a graphical component that enables to view graphically programs and processes as well as their relation with respect to lineage tracking It is possible to browse their hierarchy and dependence When an entity is selected its complete property set shows up in the property view e The property view visualize the properties of an entity selected in the lineage browser 11 4 2 Lineage Summary As mentioned above this panel is used to visualize the entities processes and programs that have been logged to the database A certain number of attributes like among others name package version or description can be seen A screenshot of the lineage summary can be observed in Figure 11 9 Package Name Version Status Instances Author y Processes 4 lineage ProcA 1 0 Stable 11 lineage ProcB 1 0 Stable 22 loan LoanProcess 1 0 Stable 2 Cesare Pautasso math_factorial
16. Unpacker mode there is no way to extract the attributes from the element so an Unpacker will not be created for elements with attributes 62 10 2 AUTOCONNECTION e HTTPS WSDL files found at HTTPS URLs may not be successfully imported unless your Java Eclipse environment is correctly configured for SSL 10 2 Autoconnection JOpera takes an existing data flow graph and attempts to add data flow bindings between matching parameters The user can access the feature by double clicking on a parameter or by selecting some tasks and or parameters and then right clicking and choosing Auto Complete Automatically Connect Parameters n I Connection Tool Delete Auto Complete Automatically Connect Parameters ie Show System InboxParameters gt Link Parameters with New Program Show System OutboxParameters Hide Disconnected Parameters Refactor EE Se Figure 10 4 Context Menu Selection On an empty selection every possible connection is added to the process displayed If the user has selected a parameter this parameter is auto connected and if the user has selected a task the parameters of this tasks are auto connected It is possible to configure in the preference dialog if hidden parameters should be connected too and if already connected parameters should be ignored Depending on if type information are visible or not this feature matches parameters only by name or by name and type information Editor
17. file Given that there are no problems check the Problems view the process should be compiled upon saving the corresponding OML file All you need to make sure is that in the menu Project Build Automatically is selected Alternatively you can compile the process by selecting Build All in the Project menu 4 9 Executing and Monitoring the Process In order to run a process click on Run in the Run menu In the Run dialog select JOpera Process and then click the New button This will create a new launch configuration Choose the process which is to be executed by pressing the Browse button and then select the process in the new dialog Now 20 4 WEB SERVICES TUTORIAL A TemperatureService oml X Process NewProcess General Information O abstract C Comment Published L subprocess Name getTemperature Author Description Parameters and Constants Constants 0 Name emp Inbox Parameters 1 Type zip String Default value 3 Outbox Parameters 1 Description temp String gt SubProcesses 0 ba E Activities 0 Name Activator Condition Priority Overview Process NewProcess view ControlFlow view DataFlow Figure 4 4 Adding Input and Output Parameters complete the launch configuration by filling in the values for each of the process input parameters The process will be started as soon as you click on Run Monitoring the progress
18. in the Monitor Per spective Why Make sure that the Project Build Automatically is checked Then modify the source OML file and re save it Otherwise try to do a clean build of the project with Project Clean Or maybe it is a good time to restart the entire workbench Project Run Window Help Open Project Glose Project BB Build al Ghrl B Build Project Build Working Set Build Automatically Properties Figure 7 8 Make sure that the projects are built automatically e How do I change the default port of the embedded application server The port is defined as a java system property You need to start eclipse with the following command line eclipse vmargs Dch ethz jopera common jetty port 8081 46 7 7 TROUBLESHOOTING Note From Version 2 3 4 you can also use the Engine Threads preference page to configure the port and start and stop the embedded HTTP server e I need to use a proxy to access a Web service How do I configure JOpera You need to configure the Eclipse JVM with the proxy address There is a plugin on http www x parrots com eclipse to help you with that Otherwise you can start eclipse passing the following arguments eclipse vmargs Dhttp proxyHost my proxy com Dhttp proxyPort 9999 e How do I switch on log4j output Look for the file eclipse plugin ch ethz jopera common config log4j properties If it is not there create it You can also rename the sampl
19. of the execution is done by switching the Editor into the monitoring mode In order to do so simply click on the Monitor Mode button You need to have either the Data Flow or Control Flow opened in order to switch into monitor mode Refer to Figure 4 9 in order to find the button As soon as you have switched to the monitoring mode you are no longer able to edit the process In order to monitor and debug execution of the newly composed process you need to run it exactly as outlined at the beginning of this section If you do so the boxes of the process and tasks will be colored with respect to their current state This means they will be colored orange shortly after the process has been started indicating that they are running as depicted in Figure 4 10 If the process or the task finishes successfully the boxes will be colored blue e Problems 3 D errors 6 warnings O infos Description Resource i Inbox Parameter temp is disconnected ITempConverter omi Qutbox Parameter return is disconnected ITempConverter omi Process MewProcess contains no tasks ITempConverter omi Process temp_converter contains no tasks ITempConverter omi Process Input Parameter celsius is disconnected ITempConverter oml Process Output Parameter Fahrenheit is disconnected TTemp Converter oml Lill Figure 4 5 Problems reported in the Problems view 26 4 9 EXECUTING AND MONITORING THE PROCESS WUndo move resize I Connection T
20. references the program you just added The process has the same input and output parameters and if you check the data flow view they are already connected to your program which is now ready to test 2 Save the OML file Note Make sure that the Project Build Automatically option is checked in the main Eclipse menu 3 Click on the Start button to start the process The button is located in the Overview tab next to the list of processes as shown in Figure 3 8 Since this is the first time JOpera will prompt you to enter some values for its input parameters Run i xj Create manage and run configurations Configurations Name Test_HalloWorld Eclipse Application ES Java Applet O Java Application AS E Start Options E common E a JOpera Process Process Name T y Tera Test_HalloWorld Browse Ju JUnit Plug in Test Input Parameters E SWT Application Parameter Type vale in String New Delete Apply Revert Figure 3 9 Launcher for the test Process 4 As shown in Figure 3 9 enter World for the input parameter in and click Run 21 3 HELLO WORLD TUTORIAL 3 5 Checking the Results If all went well the process runs very fast and is finished by the time Eclipse has switched to the JOpera Monitor perspective all halloworld omi x HalloWorld State Finished ControlFlow EI Abstract Fa A SE O I TI Descriptio A O Name TesstHalloWorld O
21. wsif Plugin XPATH Section 13 16 on page 98 ch ethz jopera subsystems xml Plugin XSLT Section 13 16 on page 98 ch ethz jopera subsystems xml Plugin Many examples are provided showing how to use these component types See Section 2 5 on page 13 96 13 2 ASYNCHRONOUS SOAP MESSAGE ROUTING 13 2 Asynchronous SOAP Message Routing 13 3 Asynchronous Local Messaging 13 4 BPEL snippets A library of predefined BPEL snippets is found in the lib bpel library 13 5 Condor Job Submission 13 6 JOpera ECHO This component copies the content of the input system input parameter into the output system output parameter and finishes immediately The input system parameter value can be set as a concatenation of the input parameters Echo a hah This will repeat the value of input parameter a twice after the string Echo If the output system parameter contains XML tags matching the names of the output parameters like b and c their values will be initialized from the content found within those tags lt b gt Echo fah lt b gt lt c gt Another output Parameter lt c gt After running this code with input a set to 123 the b output parameter contains Echo 123 and the c output parameter contains Another output Parameter 13 7 JOpera Delayed ECHO This component repeats all input parameters values in the output parameter values Use the delay system input parameter to control how long it waits before finishing the execution Als
22. xml 5495 2008 12 17 14 29 22Z cp 1 INTRODUCTION 2 Getting Started 2 1 Installation Installing JOpera for Eclipse is done in a few steps 1 Start Eclipse Note If you do not already have an installation of Eclipse 3 3 or 3 4 download it from http www eclipse org unzip it and start it 2 Select the Help Menu and click on Software Updates and then on Find and Install Select Search for new features to install and push the Next button Welcome Help Contents Tips and Tricks Cheat Sheets Software Updates d ay Find and Install About Eclipse Platform Manage Configuration Figure 2 1 Help Software Updates Find and Install 3 Push the New Remote Site button on the top right Enter JOpera as name and http www update jopera org as URL and hit the Ok button Update sites to visit A Select update sites to visit while looking for new features Sites to include in search O al Eclipse org update site EN jew Remote te New Local Site x Mew archived te Name fiopera GG URL http jwww update joperaorg Edit Remove Carcel Import sites Export sites IV Ignore features not applicable to this environment Finish Cancel Figure 2 2 Adding the JOpera Update Site 2 GETTING STARTED Then check select the box of the newly created JOpera site as well as of the Eclipse org u
23. 1 26 2006 09 02 14 59 46 18 25 52 18 32 53 2006 09 02 2006 09 03 2006 09 03 19 16 10 2006 09 09 19 16 37 2006 09 09 13 49 46 2006 09 02 14 20 59 2006 09 02 14 21 27 2006 09 02 14 59 46 2006 09 02 18 25 52 2006 09 03 18 32 53 2006 09 03 19 16 10 2006 09 09 19 16 37 2006 09 09 13 49 46 14 20 59 14 21 26 14 59 46 18 25 52 18 32 53 19 16 10 19 16 37 Figure 11 12 The search capability After having entered a search string and pressed the search button or pressed return the result shows up like in Figure 11 13 Here as well like in the summary view the refresh button on the top right of the view can be used to refresh the view content Additionally when an instance in the instance browser is double clicked the corresponding graphical element shows up in the lineage browser panel 11 4 4 Lineage Browser The lineage browser is used to browse graphically the entities instances A starting point could be what is seen in Figure 11 14 When a process is double clicked it is opened or closed depending of its initial state We see for instance in Figure 11 15 the initial process that has been opened displaying its internal task Any entity that is selected displays its properties in the property panel as seen in Figure 11 16 The contextual menu over an entity displays what can be done with it Commands from the following list are available e Get Parent retrieves hierarchical data from the databas
24. 3 D oo Mm LA B La FJ Ul VU A A A A A A NI 23 Y contains starts with ends with equals nstance id 1 23 23 123 23 23 wos A A da w PJ Any Attribute contains HH WALL 0 117 0 098 0 197 10 11 0 233 0 096 0 136 0 083 0 118 0 118 State Finished Finished Finished Finished Finished Finished Finished Finished Finished Start Date End Date 11 LINEAGE TRACKING z Ready Date r 2006 09 01 13 54 39 2006 09 01 13 54 39 2006 09 01 13 54 39 2006 09 02 2006 09 02 2006 09 02 2006 09 02 2006 09 03 2006 09 03 2006 09 09 2006 09 09 13 49 46 14 20 59 14 21 26 14 59 46 18 25 52 18 32 53 19 16 10 19 16 37 2006 09 02 2006 09 02 2006 09 02 2006 09 02 2006 09 03 2006 09 03 2006 09 09 2006 09 09 13 49 46 2006 09 02 14 20 59 2006 09 02 14 21 27 2006 09 02 14 59 46 2006 09 02 18 25 52 2006 09 03 18 32 53 2006 09 03 19 16 10 2006 09 09 19 16 37 2006 09 09 Figure 11 11 The instance browser State Finished Finished Finished Finished Finished Finished Finished Finished Finished Start Date End Date 7 Ready Date 13 49 46 14 20 59 14 21 26 14 59 46 18 25 52 18 32 53 19 16 10 19 16 37 2006 09 01 13 54 39 2006 09 01 13 54 39 2006 09 01 13 54 39 13 49 46 2006 09 02 2006 09 02 2006 09 02 2006 09 02 2006 09 02 2006 09 03 2006 09 03 2006 09 09 2006 09 09 14 20 59 2006 09 02 14 2
25. Console view in the Eclipse user interface Refer to the Section JOpera Kernel Command Line Reference for more information on the available commands e Can I access a JOpera server remotely Of course through its Web service interface JOpera comes with two different interfaces Each published process can be started by invoking it as a Web service their WSDLs are automatically generated and listed under http localhost 8080 wsd1 The raw engine API is accessible from http localhost 8080 api APIService wsdl Note These URLs are only activated if you install the Web Services plugins for JOpera e Can I connect to a JOpera server with the Monitoring perspective Yes but only if the server runs on the same machine as the client Remote monitoring is currently disabled by default mainly for security reasons Contact client jopera org if you are interested in remotely monitoring your JOpera server You can also use the new Monitoring Widget Section 5 2 on page 31 7 6 Other questions e How does JOpera relate to BPEL JOpera and its visual composition language are a bit more general than BPEL which focuses on orchestration of Web services only More in detail there are several important differences Even concerning Web services most BPEL tools cannot call a service described by a pure WSDL 1 1 document as this description needs to be augmented with additional metadata i e the partner In JO
26. Counter COND TRUE PRIORITY 0 PROGRAMID Program9 gt lt ACTIVITY OID Activity43 NAME JSCounter DESC ACT Finished BPELWait OR TRUE COND value lt gt DEP 4 SYNCH 0 FAILH 0 PROGRAMID Program14 gt The ACT attribute of the JSCounter task expresses that this task is either started upon execution start of the process or after the BPELWait task has been finished execution The COND attribute ensures that the task will only be executed as long as the value of the parameter value is not equal to the value of the parameter to which is an input parameter of the process 9 3 3 Arbitrary loop A part of the workflow where one or more activities can be done repeatedly This process runs A Merge B Mergel C D E Mergel C D Where the bracketed sequences can be repeated an arbitrary number of times In practice the number of times the loop is repeated is controlled by the conditions on the counter parameters which compare them to the process input parameters loopA loopB controlling how many times each loop is executed 9 3 4 For each loop The same task of a process is repeated for each element of a list DT 9 JOPERA VISUAL COMPOSITION LANGUAGE REFERENCE 9 4 Data Flow Patterns 9 4 1 Discriminator 9 4 2 Shared State 9 4 3 Global State 9 4 4 Persistent Data 9 4 5 Generic Data Transformation 9 5 Advanced Patterns 9 5 1 Recursion 9 5 2 Timeout 9 5 3 Dynamic Late Binding
27. Delete Edit Stark Figure 2 7 The Overview page of the OML Editor LA Properties Jopera Library 3 errors 4 warnings O infos Filter matched 7 of 219 items Description Resource Path Location E Errors 3 items Inbox Parameter NewInboxParameter has a duplicate name ws_quiz oml client NewProgram3 Mewl Inbox Parameter NewInboxParameter has a duplicate name ws_quiz oml icient ewProgram3 MewI Program NewProgram3 contains no Adapters ws_quiz orl client Se Go To E ts Warnings 4 items Outbox Parameter Continue is disconnected ws_quiz oml client amp Outbox Parameter Output is disconnected ajax_gmap oml client Copy Process NewProcess contains no tasks ws_quiz oml client Program doGetCachedPage Version 1 0 is deprecated GoogleSearch2 oml client ws api Show In Paste Select All etCachedPage Quick Fix Properties Figure 2 8 Look out for JOpera Errors and Warnings in the Problems View JOpera Library The JOpera library displays what are the currently available programs and processes that can be composed Like with the Outline to add a new task to a process you can drag and drop selected elements into a data or control flow view of an Editor Displayed elements can be interactively searched and browsed by grouping them using several criteria 2 JOpera Library X 77u Group By Component Type Search e Group By Package lb bpel 3 Group By A
28. New gt JOpera Project Choose an appropriate Project name test in this case and click on the Finish button 4 3 Importing a WSDL File As soon as the new project has been created right click on the newly created project Select Import from the context menu and subsequently choose the new WSDL Import from the Import dialog and click on next On the next dialog define the project name if not already defined and the URL of the WSDL description file of the Web Service which is to be imported The Web Service used in this tutorial is a simple temperature reporting service which can be found at http www xmethods net sd 2001 TemperatureService wsdl 23 4 WEB SERVICES TUTORIAL Import WSDL into JOpera This wizard imports a Web Service described by a WSDL document into JOpera Container URL or File Target OML File SM e E ecc Connection Type Input Format Qutput Format SOAP 1 1 Leaves only Leaves Only soar 1 2 With Packer With Unpacker _ HTTP Get _ HTTP Post Figure 4 2 Defining the URL of the WSDL file Note XMethods has become very unreliable recently If you have trouble with the above Web service you may want to look for a similar alternative at http webservices daelab net temperatureconversions TemperatureConversions wso WSDL Clicking on Finish will finally import the Web Service description 4 4 Creating a new Process Double clicking on the ne
29. Now it is time to bind the program with the adapter to invoke Java snippets To do so look for the Adapters section and as shown in Figure 6 2 e click on the Add button e Select the JAVA SNIPPET component type e Click OK to close the Component Type Browser The actual code for the snippet is entered in the specific Adapter tab e click on the Adapter JAVA_SNIPPETAdapter tab e Enter the code to multiply two numbers result a b directly in the Script parameter as shown in Figure 6 3 e Click on the Insert Variable button to display which parameter variables have been declared 6 1 2 Testing the Java snippet To test the snippet we will create a Test process and run it e Click on the Overview tab Select the Multiply program Click on the Test button this will generate a new test process called Test_Multiply and your file will look like Figure 6 4 Click on the Start button Make sure the file is saved 39 6 JAVA SERVICES TUTORIAL Program Multiply 1 0 General Information Pl Abstract Comment Name Multiply Author Cesare Pautasso Version 1 0 Stable HH Delete this Version Description Use a Java Snippet to multiply two floating point numbers Execution Settings Parameters y Inbox Parameters 2 Add a float in b float Type float Delete w Outbox Parameters 1 result float Default Value Name result Description This stores the result ofthe
30. This can only be done by upgrading the JOpera runtime Until the runtime has been updated this option will be set to disabled Optional Input Output Parameters Some WSDL files create choices by declaring two or more optional message parts This can be done by setting the MinOccurs to 0 However creating optional message parts in JOpera is as yet not possible because it would need the runtime to be changed Until the runtime has been updated all optional fields will be inserted as if they were mandatory and the user must edit the input output messages himself Unbounded Input Output Parameters Some WSDL files create arrays by declaring an element to have a maxOccurs of unbounded or greater than 2 for that matter The importer cannot as yet handle such fields and will only add one parameter for each declaration instead of an array declaration Cycles in the definitions Some WSDL files creates definitions with elements referencing each others e g an articles has n citations which are themselves articles with citations etc The importer cannot handle Cycles in the Leaves Only mode Input Element Attributes Some WSDL files creates elements with attributes instead of sub elements In the Packer mode those attributes cannot be properly processed and will be added to the parent Packer or to the Program if the element is defined there Output Element Attributes Some WSDL files creates elements with attributes instead of sub elements In the
31. VICE INVOCATION PLUGINS lt COMP ABSTRACT false OID CT_HTTP EXTENDS CT_SERVICE NAME HTTP DESC Download a page f lt INBOX gt lt PARAM OID INPARAMHTTP1 TYPE Enum GET POST PUT DELETE OPTIONS HEAD NAME method DESC lt PARAM OID INPARAMHTTP2 TYPE URI NAME urlstring DESC URL of the HTTP Request gt lt PAF lt PARAM OID INPARAMHTTP3 TYPE Text Advanced NAME headin DESC Header of the HTTP Req lt PARAM OID INPARAMHTTP4 TYPE Text NAME body DESC Body of the HTTP POST PUT Request lt INBOX gt lt OUTBOX gt lt PARAM OID OUTPARAMHTTP3 TYPE String NAME headout gt lt PARAM gt lt PARAM OID QUTPARAMHTTP5 TYPE Map NAME responseheaders gt lt PARAM gt lt PARAM OID DUTPARAMHTTP4 TYPE String NAME page gt lt PARAM gt lt OUTBOX gt lt COMP gt lt COMPS gt lt OCR gt Each element of the definition has a NAME identifier which is shown to the user and an OID identifier which is used internally to reference the elements of the definition Additional documentation can be entered in the DESC field Parameters are grouped into input and output parameters Input parameters are filled in by JOpera and passed to the adapter code carrying the information used to start the service invocation Output parameters are filled in with the result of the invocation by the adapter so that JOpera can store the results and forward it to the next tasks of the workflow 12 5 2 Editing System Parameters
32. Workflow Patterns Examples patterns oml The workflow patterns More information in Section 9 on page 53 signals_example oml Examples using the system signals library showing how to cancel suspend and resume the execution of a process from within the process itself 14 Part Tutorials 3 Hello World Tutorial In this tutorial you will write a very simple process with one component which says Hallo World Doing so you will learn the basic skills needed to work with JOpera s visual development environment creating JOpera projects and model files setting up new programs and testing them 3 1 Creating a new Project In order to create a new Project right click in the JOpera Navigator You should see this view in the JOpera Design perspective li Py Project 4 0 JOpera Project 5 0 OML File Ei Import Py Example py Export Py other Ctrl Refresh Figure 3 1 Creating a new JOpera project and select New gt JOpera Project Choose an appropriate Project name test in this case and click on the Finish button 3 2 Creating a new OML file Now that you have an empty JOpera project you can add OML files into it by right clicking the project in the JOpera Navigator and selecting New gt OML File New OML File xj New OML File This wizard creates a new JOpera file oml Enter or select the parent Folder test test File name ELM Adva
33. ace Component Type Browser x Search Text m Matching Items 2 BPEL BS CONDOR 29 ECHO 2S HTTP 22 HUMAN Bo INVOKE ES Java BS JAVASCRIPT 22 MSG BS PEC 2 RECEIVE aS REPLY 23 ROUTER BS soap 29 sQL I Y BO ccu chan hd Qualifier 1 system ECHO ce 19 Choosing a component type for the new adapter The content of this list may change depending on what JOpera plugins you have installed 20 3 HELLO WORLD TUTORIAL Access Method NewAccessMethod lt out gt Hallo n lt out gt in String Input KT Insert Variable Program HalloWorld Access Method New ccessMethod Figure 3 7 Entering the XML snippet to be returned by the program You can get the list of input parameters by typing CTRL 5Space 3 4 RUNNING THE PROGRAM WITH A TEST PROCESS 3 4 Running the Program with a test Process Now that we have setup the HelloWorld program we can run it by calling it from a test process lox File Edit View Navigate Search Project Run Window Help 0 3 7 woo Fy X Be i oF R oe oP ak IS Overview v Processes v Programs g Test_Halloworld Halloworld Overview Program Halloworld Access Method NewAccessMethod Figure 3 8 Generate a Test Process for the Program 1 Select the HalloWorld Program and click on the Test button Note This will create a new process which contains a single activity which
34. ak is set before that section where the output document has pages at all i e the pdf version lt subsec gt Subsection for sectioning sections name Title of that subsection lt subsubsec gt Subsubsection for sectioning subsections name Title of that subsubsection lt list gt List its items will show a bulleted list see item below lt item gt List item one point bullet of the list see list above lt steps gt Encloses a nubered list for step by step descriptions lt step gt One numbered step see steps above type Optional attribute for specifying the kind of the step its value is put in boldface with an appended colon in front of the step description 99 14 HOW TO WRITE DOCUMENTATION lt menu gt An entry of the mainmenu produces a table for its menuitems see menuitem below name Caption of the menu entry lt menuitem gt An entry in a menu see above name Caption of the menu entry lt menucomment gt A comment subsectioning the table of menuitems type optional e option Sets introductory phrase on optionality of the following menuitems lt code gt For code segments is verbatim all signs allowed no escaping necessary lt fig gt For figures pictures file The source file of the figure text The figure description label If specified this is the label for references from other positions in the document If not specified a label with name fig_ plus the file name of th
35. ameters method PUT urlstring http www2 doodle com apil poalls pollid body Advanced System Parameters headin x DoodleKey DoodleKey Program PutPoll 1 0 Adapter HTTPAdapter HTTP e e Figure 12 5 The HTTP adapter input parameters displayed in the adapter editor tab e public void Execute IJob Job The Execute method is called by JOpera to invoke a service The information controlling the invocation is stored in the IJob parameter e public State Signal int Signal The Signal method is used by JOpera to interact with an active invocation e g in order to abort it As a first approximation it is not necessary to implement this method as it may not always be required to provide such advanced functionality 12 7 The IJob Interface The information describing the service invocation to be performed by the plugin is packaged into an IJob object which is passed as a parameter to the execute method This object is used to store all input output parameters of the service invocation and also to inform JOpera of the final outcome of the invocation i e whether it was successful or it failed The most important methods of IJob are e getInput get ActiveCommand getOutput getSystemOutput setState 90 12 8 CONTROL FLOW MAPPING e notifyFinished Their usage will be explained in the following sections First we discuss how to transfer control then how to report failures in the invoc
36. arameters job getSystemOutput put sys_output set output parameters job getOutput put output detect failures somehow and set the outcome of the job 92 12 13 EXAMPLE CODE FOR ASYNCHRONOUS INVOCATION if ok job setState State FINISHED else job setState State FAILED 12 13 Example Code for Asynchronous invocation void Execute IJob job take the system input parameters Map c job getActiveCommand start running something with it do not change the state of the job it is the responsability of the plugin to call this method from its own thread whenever the service invocation has completed asynchronously void Complete IJob job set system output parameters job getSystemOutput put sys_output job getOutput put output if ok job setState State FINISHED else job setState State FAILED notify JOpera about it job notifyFinished 93 12 HOW TO WRITE SERVICE INVOCATION PLUGINS 12 14 Example Code for partial result notification 12 15 Example Code for progress notification 12 16 Example Code for safe streaming intermediate output 12 17 Example Code for the Signal Method This is the simplest implementation of the signal method No matter what signal is given to the subsystem the state of its job is left unmodified i e it remains Running public State Signal int Signal by default indicate that the sig
37. ation and finally how to transfer data 12 8 Control flow mapping The execute method of the ISubSystem interface is called by JOpera in a dedicated thread to perform the transfer of control from a running task to the corresponding service provider This can happen synchronously a thread waits or asynchronously initiated by a thread and completed by another 12 8 1 Synchronous Service Invocation In the simplest case this happens synchronously This means that the service invocation is completed by the time the execute method returns This is straightforward to implement as all the code for initiating the invocation e g sending a request to the service provider and completing it e g reading and decoding the response is contained in the execute method which can be structured in the following three steps 1 Call the service provider 2 Wait for an answer 3 Retrieve the response 12 8 2 Asynchronous Service Invocation Depending on whether the service is invoked locally or remotely and depending on how long the service invocation typically lasts it may not be efficient to keep waiting for an answer as this keeps the thread running the execute method busy To address this problem as an alternative it is also possible to use the execute method to only perform step 1 i e initiate the call and handle the other steps asynchronously so that the thread invoking the service does not block and can be used by JOpera to run other
38. can of course be recursive if the underlying parameters are themselves complex types e Output Format If a program that is generated from an operation needs complex output parameters two different output scheme can be used The Leaves Only mode will generated an output field for every parameters that can contain a value indipendent on the structure of the output message It is then the responsability of the different adapters to handle the extraction of the complex type The With Unpacker Mode on the other hand will generate one output field for every output parameter in the message indipendent on the type of the output simple or complex The adapters have to create unpackers that will extract the the underlying output parameters given the complex type The unpacker structure can of course be recursive if the underlying parameters are themselves complex types 10 1 2 Selecting the Operations If the user wants to select which operations should be imported and which should not he can use the next button instead of the finish button The wizard will then show a list of the different operations found in the WSDL file preceded by the connection type to differentiate operations with the same name but different access modes Using the different buttons between the two lists the User can then select the operations to import The Selected Operations will be imported and the Available Operations have been found in the WSDL but won t be impor
39. cess watch its state and interact with it Instance Navigator The Instance Navigator gives an overview over all of the processes that JOpera is or has been run ning The color of the dots indicates their current state You can get more details on a running process instance by clicking on it which will open or switch to the corresponding graphical editor This view also let you interact with processes where they can be terminated or killed suspended resumed and even deleted Instance Navigator X v Delete All Delete Terminate Suspend Resume gf SimpleProcess 3 0 1 2 Figure 2 12 The instance navigator view Monitoring Processes in the Editor Please note that in the monitor perspective you no longer can edit the processes as they are being executed by JOpera Instead the editor will change the color of the task boxes according to their current state of execution An orange box indicates that a service is currently being invoked JOpera is waiting for a response A box will then switch to blue when a successful invocation has finished and red when something has failed In the data flow view shown in Figure 2 13 parameters boxes will show the first few characters of their content when hovering the mouse over a parameter box JOpera will show you a tooltip with its current value you can also select a task box to read information about its runtime execution state in the Propert
40. e You can find more information on http www eclipse org articles Article Your 20First 20Plug in YourFirstPlugin html on how to write and run Eclipse plugins 12 1 Adapter Metaphor The theory behind JOpera s adapters is described in this paper http www jopera org docs publications 2004 megaprogramming An adapter maps a high level abstract service invocation down to a well define concrete binding to a particular service invocation technology Adapters bound to services are configured at design time through a set of system parameters defined with a oml file passed to the JOpera core plugin Section 12 5 on page 87 At run time the system parameter values which specify how to invoke the service based on the type of the adapter are passed to the actual adapter implementation which is plugged into the JOpera kernel plugin Section 12 6 on page 89 The goal of this chapter is to describe what kind of parameters can be used to model a certain type of service invocation mechanism and also to discuss different interaction patterns supported by the JOpera kernel adapter interface called ISubSysten 12 2 Example service invocation plugin To get started you can download from the JOpera website http www jopera org download demos a sample Hello World demo adapter 12 3 Setting up a new service invocation plugin This section describes how to create a new Eclipse plugin which extends the extension points needed to insert a service invoca
41. e and shows the selected entity in its parent context e Set New Root a child entity can be chosen as the new root of the graphical representation e Expand All recursive open of the complete subtree rooted by the selected element 80 11 4 LINEAGE TRACKING Lineage Summary a Instances of ProcA Ez Any Attribute contains HH 09 09 Instance id in out 8 23 g 23 10 23 11 23 WALL 0 083 0 118 0 172 0 146 State Finished Finished Finished Finished Start Date End Date Ready Date 2006 09 09 19 16 10 2006 09 09 19 16 10 2006 09 09 19 16 10 2006 09 09 19 16 37 2006 09 09 19 16 37 2006 09 09 19 16 37 2006 09 09 19 16 47 2006 09 09 19 16 48 2006 09 09 19 16 47 2006 09 09 19 18 01 2006 09 09 19 18 02 2006 09 09 19 18 01 Figure 11 13 The search result Figure 11 14 A process in the lineage browser e Collapse All recursive close of the complete subtree e Expand Process open the selected process equivalent to a double click on it e Collapse Process close the selected process equivalent to a double click on it We see a screenshot of the context menu in Figure 11 17 Finally we see the result of the previous process after having run the Get Parent command in Figure 11 18 ProcB is here represented as mentioned in its parent context of ProcA 11 4 5 Property Panel The property panel is just a normal property panel as shown in Figure 11 16 It simply displays the properti
42. e figure is generated width Optional width of the figure can be specified relatively to the page width number and percentage sign recommended or absolutely in points just a number The html translation ignores this while simply putting the figure in original size lt note gt Annotation lt ref gt Reference to some label defined elsewhere as attribute of a fig sec subsec or subsusec tag label The label referred to type Can be specified for section references see produces a see phrase for that ref lt ur1 gt Hyper link just as single tag like lt url href http www google com gt lt url gt href The URL lt footnote gt Footnote lt faq gt Construct for the usual question answer pattern Expects a sequence of question and answer pairs as child tags lt question gt FAQ question simple text a question mark is appended lt answer gt FAQ answer in contrary to the question tag other elements tags are allowed lt tag gt name Name of that tag lt attr gt name Name of that attribute lFor rapid highlighting of some word term just enclose with apostrophes 100
43. e file To configure the level of detail of the traces add the following line into the file log4j logger ch ethz jopera DEBUG where ch ethz jopera is the package for which you want to switch debugging output on More information on how to configure log4j can be found in the readme txt file 47 48 7 FREQUENTLY ASKED QUESTIONS 8 How To 6 1 How to publish a process as a Web service Actually you do not have to do anything to publish a process as a Web service its WSDL interface description is generated by JOpera automatically 1 To look at which processes are currently published you can point your browser to http localhost 8080 wsdl i x File Edit View Go Bookmarks Tools Help lt a v o gt y E E YN E http localhost 8080 wsdl list lic Processes Published as Web Services Test sl wsdl E Find HalloWorld Find Next Find Previous Highlight ST Match case http localhost 8080 wsdl process Test_HalloWorld Adblock 4 Figure 8 1 The WSDL of the process is generated automatically by JOpera 2 You can use the WSDL to call the process from your own client and see what happens as shown in Section 4 1 on page 23 You should compare the overhead of going through the Web service doing so with a normal JOpera subprocess call Note To control whether a process is published as a Web service use the Published checkbox in the main page of the process editor A
44. e identified by name The processName identifies the process template to be undeployed Note Processes should only be undeployed if there are no active running instances otherwise the kernel may be left in an inconsistent state Examples e delete template demo This will undeploy the process template called demo 13 74 10 FEATURE REFERENCE 11 Lineage Tracking Reference about the data lineage tracking functionalities 11 1 Versioning 11 1 1 Introduction The versioning represents an extension to JOpera aiming at a better version management of processes and programs It enables to qualify a version with a tag e g stable unstable or deprecated and provides UI functionalities to duplicate existing entities and increment automatically their version number 11 1 2 Use The use of versioning is straightforward The general information section as seen in Figure 11 1 provides a line for version management and a few corresponding widgets Process ProcA 1 0 General Information O Abstract C Comment Published C Subprocess L Flow Control Mame Proc Author Version 1 0 Stable H Delete this Version Figure 11 1 The versioning widgets in the general information section Duplication A duplication of the current process or program is performed when the Create New Version button is clicked By doing so the version number is automatically incremented Deletion Similarly the deletion of the current
45. e switched to the new interface 10 3 2 Extract sub process The user may select a set of services in any of the views including the control flow of a process and choose to apply the process extraction refactoring Figure Figure 10 12 The user s selection is reduced to tasks and constants This implies that the user can select tasks and constants by drawing rectangles Selected parameters are then ignored The user may choose the new Process name in the Wizard Figure Figure 10 14 left A new process is created with the selected content which is replaced by a SubProcess referencing it in the original process Figure Figure 10 15 middle and right 10 3 3 Inline sub process Inlining is the inverse to extracting whereby a SubProcess is replaced by the content of the referenced Process The user may select a subprocess and select the inline refactoring in the context refactor submenu Figure Figure 10 17 The user may decide on the scope of the refactoring which can be either selection file project or workspace Choosing the workspace scope the user can decide if the inlined process should be deleted automatically afterwards 64 10 3 REFACTORING i Figure 10 7 Autoconnect Example before 65 66 10 FEATURE REFERENCE Stock Quote Convert Full ll Currency switzerlan Symbol IBM Default Currency USA i Symbol Default Currency 4 get Quote get Rate a Original Price O
46. ee Section 1 2 on page 1 for more information on all the new features that have been added during the port Where can I download the source code of JOpera Currently the source code of JOpera is not yet available to the general public If you would be interested in contributing to the project or you have any other specific reasons for needing the source code of JOpera please let us know Questions about Developing Processes What is a process template A process template describes how the tasks its components are connected together It contains a control flow graph which specifies the partial order to follow when starting the tasks as well as the data flow graph which defines how tasks exchange data A process templates is stored in an OML file What is an instance A process instance represents a running process template and contains the state of one execution including all data that is produced and consumed by the tasks Multiple instances of the same template can be active at the same time You can use the Section 2 4 6 on page 11 view in of the JOpera Monitor perspective to check what are the instances currently managed by the JOpera Kernel What is a task A task is a basic process component It can either be an activity or a subprocess What is an activity An activity represents the invocation of an external program or service through a variety of protocols What is a program A program is any software component or external sy
47. encing same process Delete process after inlining fi Figure 10 18 Refactoring Wizard 10 3 REFACTORING Stock Quote Convert Full Currency switzerlan i Symbol IBN Default Currency USA Default Currency Currency Stock Quote Convert Full Figure 10 19 Dataflow of parent process after 71 10 FEATURE REFERENCE 10 4 JOpera Kernel Command Line Reference By opening the JOpera Kernel Console view you can access the low level command line interface of the JOpera process execution kernel From it you can bypass some of the GUI to directly access some of the internals of the kernel El JOpera Kernel Console _X Di x l start Test_NewProgram Test_NewProgram 0 0 Figure 10 20 The JOpera Kernel Console view This is recommended only for expert users that are trying to debug the system develop additional functionality and have not exposed the new features through a more user friendly UI In this section we document some of the command lines that are currently supported by the JOpera Kernel Console view 10 4 1 Starting processes start processName inputParameterValues This command starts the execution of a new process processName This is the name of the process to be started input Parameter Values Input Parameters are passed using a URL CGI encoding On the command line the inputParameterValues are listed using a URL CGI encodin
48. ent to start a process using any of the above languages e What if I want to call a process from a Java application It depends you can also go through the previous solution if you want to keep a certain degree of separation between your Java client application and the JOpera process Otherwise especially if you are writing your Java application as an Eclipse plugin tighter forms of integration are Properties amp BS Kernel Console Y Error Log OBESE ln Bee System Parameters CALLER delete_on_finish ENDDT 2008 04 01 09 54 36 640 Finalized Yes READYDT 2008 04 01 09 54 30 078 START 1 STARTDT 2008 04 01 09 54 30 078 STATE 4 SuspendAfterCreation WALL 6 562 ES iv ES Figure 7 7 Logged execution times shown in the advanced properties view 44 7 5 RUNNING JOPERA AS A SERVER possible 7 5 Running JOpera as a server e How do I start the JOpera server from the command line No need to install any additional component You just need to run a special headless Eclipse application called ch ethz jopera kernel KernelApplication and pre configure the workspace where the OML files are pre deployed For example eclipse application ch ethz jopera kernel KernelApplication data home jopera workspace nc will start the JOpera server using the workspace in home jopera workspace e How do I control a local JOpera server You can access JOpera from the command line just like you would using the Kernel
49. er and password should be set up The next step is to enter the database connection information in JOpera This can be done using Eclipse Jopera s preference page as seen in Figure 11 4 11 3 Memoization 11 3 1 Introduction Memoization allows executed instances of programs or processes to get cached in the database Later on a reexecution of the same entity with the same input parameters can be restored directly from database without being reexecuted This is especially interesting for entities that are either fully deterministic or deterministic within a certain time window and in addition have a large execution latency 76 11 3 MEMOIZATION 656 Preferences type filter text Lineage A a e JOpera Lineage Preferences An gt Help W Enable Lineage Logging restart required Install Update Database Connection Settings gt Java URL jdbc postgresgl wilab2 inf ethz ch 5432 lineage y JOpera Editor User lineage Editor Sticky Lineage Pass lin20 ak Model Checke Monitor gt Plug in Developm Pydev Run Debug Team E gt gt Figure 11 4 Database settings 11 3 2 Use of Memoization Execution Logging The use of memoization for JOpera is straightforward and can be done using JOpera UI The tooling is integrated in the execution section just underneath the general information section which are both visible in design mode A screenshot of the execution settings section is presen
50. es new TaskDisplavyer process Figure 5 5 All the processes Where the argument process is the id of the div element where the widget will be displayed e Display a single process with all pf its instances new TaskDisplayer process msg example asynch ASYNCHProcessSupplier 1 0 Figure 5 6 A single process Where the second argument is the name of the process e Display a single process with a specific instance new TaskDisplayer process msg example asynch ASYNCHProcessSupplier 1 6 1 Figure 5 7 A single instance Where the third argument is the instance number 33 34 5 MONITORING WIDGET TUTORIAL 6 Java Services Tutorial This chapter shows how Java code can be embedded or invoked from JOpera processes 6 1 Java Snippets Java Snippets are short pieces of Java code that can be very efficiently embedded into a JOpera process The code of a Java snippet is any valid Java code that can be written inside a Java method In the first part of this tutorial you will learn how to setup a JOpera program that calls a Java snippet to multiply two floating point numbers 6 1 1 Calling Java Snippets from a JOpera Program e Create a new Program and call it Multiply e Create two input parameters called a b and assign them a type of float e Create one output parameter called result also of type float The new program you have setup should look like the one shown in Figure 6 1
51. es of the selected item of the lineage browser ProcB 1 Figure 11 15 A process that has been opened sl 82 Property w General Database instance Name Package Version 11 11 ProcB lineage 1 0 LINEAGE TRACKING w Input Parameters in w Output Parameters out 4 w System Activity 0 Caller lineage ProcA 1 0 ProcB1 0 Delete on finish Finalized Yes Instance O Start 1 State Finished Suspend after creation TID lineage ProcB 1 0 0 0 Wall 0 075 w Time Enddt 2006 09 01 13 54 39 878 Readydt 2006 09 01 13 54 39 803 Startdt 2006 09 01 13 54 39 806 EEE Figure 11 16 Properties of a selected entity Get Parent Set New Root Double 1 Expand All Collapse All Expand Process Collapse Process C Figure 11 17 Context menu of the lineage browser ProcB 1 Figure 11 18 The result of Get Parent Part Ill Developer Reference 83 12 How to write Service Invocation Plugins The main purpose of a service invocation plugins or Subsystems is to enable JOpera to invoke a certain type of service using the appropriate protocols and mechanisms A subsystem plugin can be seen as an adapter which maps JOpera s representation of control flow events and data flow information into the ones used by the specific type of service A service invocation plugin is packaged as an Eclipse plugin providing an extension for the JOpera kernel and core plugins Not
52. ess and its activity may be successfully built and deployed the Program may have an error and thus is not compiled and deployed Thus JOpera cannot find it when it runs the activity referencing it e system configuration error Some adapters require the installation of specific JOpera plugins e g the ones for invoking Web services This means that if the plugin is not installed the activity will not be able to run A subprocess may fail for two reasons e the process to be invoked cannot be found e the process that has been called has failed How do find out the cause of the failure and how do fix it Hovering the mouse over a failed task box displayed in red will display a tooltip with some error message Select the task box this will display the value of all input parameters in the Properties view Make sure that the parameters contain the values you expect If a value is missing check the data flow view and make sure that the parameter is connected Also in the Properties view look for the System Input Output parameters which vary depending on the adapter used to invoke the service e Web services calls will display the request and response SOAP message that was sent Check if the output message is a fault message e UNIX or SSH Commands will show the entire content of their stdout stderr Also the exact command line that was run is shown in the System Input parameters You can copy and paste it into an operating sys
53. g That is the input parameters are passed as a list of name value pairs separated by the amp character Once a process has been started it is assigned a unique ID by the system which can be used throughout its lifetime to refer to it This ID is printed out in the console view Examples e start demo This will start a process called demo and use the default values for its input param eters e start demo a 123 amp b Test This will start a process called demo and pass the value 123 into its a input parameter and assigns the value Test to the b input parameter 10 4 2 Deleting process instances delete data processID This command deletes the execution state of the given pro cess instance processID This parameter identifies the process instance to be deleted The processID identifies the process instance to be deleted This is the value printed out after a process has been started using the start command Examples e delete data demo 0 0 This will start instance 0 of a process called demo 10 4 3 Listing deployed process templates show templates This command lists the names of the currently deployed processes 72 10 4 JOPERA KERNEL COMMAND LINE REFERENCE Examples e show templates This will list all processes that are currently deployed in the kernel 10 4 4 Undeploying process templates delete template processName This command undeploys a process template from the kernel processName Process templates ar
54. gn Mirror Layout Auto Complete Refactor i Y Y TY YT Conwerted Price Figure 10 13 Context Menu Selection 605 Refactoring Extract to SubProcess refactoring a This refactoring extractes the selected tasks and constants Name for new extracted Process NewSubProcess lt Back Next gt Figure 10 14 Refactoring Wizard 10 3 REFACTORING Stock Quote Convert Full rk Currency switzerlan Symbol IBM Original Price di Li HewS5ubProces Converted Price Converted Price Stock Quote Convert Full Figure 10 15 Dataflow of parent process after HewSubFrosess Original Price ua E Integrate Conwerted Price Converted Price Hew SubProcess Figure 10 16 Dataflow of extracted SubProcess 69 TO 10 FEATURE REFERENCE Original Price o Hew SubProcess lt Undo move resize I Connection Tool Delete Auto Complete Show System InboxParameters Show System OutboxParameters Refactor kT T YT Inline Subprocess Extract to Subprocess Switch Process Figure 10 17 Context Menu Selection 800 Refactoring Inline SubProcess refactoring a This refactoring inlines the selected subprocesses l Inline all occurences in file subProcesses referencing same process Inline all occurences in project subProcesses referencing same process Inline all occurences in workspace subProcesses refer
55. halloworld oml x Process Test_HalloWorld zu Reed O Abstract C Comment Published O subprocess Name Test_HalloWorld Author Description Figure 8 2 Check this box to publish process as Web services 8 2 How to debug a failed task Debugging a distributed system is a non trivial task JOpera models abstract some of the complexity of building a distributed application Still when things go wrong tools are provided that help to quickly pinpoint the cause of the problem This section contains a few tips to help you find out why a process execution has failed 49 8 HOW TO e Processes fail if any of their tasks fail and no failure handler tasks are provided An activity may fail for many reasons these are some of the most common ones e bad input the information passed in the program input parameters or in the adapter configu ration system input parameters was incorrect e for programs interacting with remote services a failure may occur due to network connectivity problems JOpera cannot reach the service provider or the service provider is offline e the service invoked runs but it fails during its execution JOpera can detect this depending on the specific properties of the adapter For example UNIX programs will fail if they return a non 0 exit code Web Service calls will fail upon the return of a SOAP fault message Java snippet will fail if they raise an Exception e compile error Although the proc
56. ices Test asmx Test_Reverse 1 0 O Reverse System HOST 129 132 130 144 java lang String 4ws SodiumTestServices Test asmx Test_ Reverse 1 1 0 0 Reverse System NAME Reverse java lang String ov O Input source Hallo World JOpera java lang String a O Output ReverseResult arepOJ dlroW ollaH java lang String O Output ToUpperResult AREPOJ DLROW OLLAH java lang String O System CALLER null O System delete_on_finish No java lang String O System ENDDT 2006 10 30 17 38 02 187 java lang String O System Finalized Yes java lang String O System READYDT 2006 10 30 17 37 51 078 java lang String O System START 1 jaya lang Integer 0 System STARTDT o 10 30 17 37 51 093 java lang String 0 System STATE O System en No java lang String O System WALL 11 109 java lang String Reverse Input source Hallo World JOpera java lang String Reverse Output ReverseResult arepOJ dlroW ollaH java lang String Y A Manavan Cikan AN OCKAME hu Cadi TackCaeniene Tack nenas Masinvenfi N1 fima Inno Cheima zj Figure 2 15 The Kernel Memory Inspector 2 5 Examples A large set of examples is included with JOpera You can load them into your project workspace by using the New gt Examples menu command of Eclipse The following non exaustive list describes some of the available examples Note The available examples may depend on the set of installed JOpera features Basic Examples halloworld oml math_factorial oml loan oml
57. ies view Additional information e g performance related is shown when showing the advanced properties for very long parameter values you can show their full content in the Parameter Viewer 11 2 GETTING STARTED Test asmx oml 23 ci source Hallo Wo 1 source diroW olla Reverse ReverseResult dlroW olla y ToUpperResult ReverseResult dlroW olla ToUpperResult A DataFlow z AFTER 7 E Efe Parameter viewer 3N Y 0 Value a E Design ivs SodiumTestServices Activator Condition TRUE Hallo World Al Description Name Reverse Program Reverse Input Parameters source Output Parameters ReverseResult dlroW ollaH E System Input Parameters AM Reverse_INYOKE destination http Sod message lt soapEnv Envelope xmins SOAPaction http fh Reverse E System Output Parameters in 4 gt Figure 2 13 Editor in the Monitor Perspective working together with the Properties and Parameter Viewer JOpera Stack The process instances calling the currently selected one can be listed by opening the JOpera Stack view Double click on a process instance shown on the Stack to open it in an editor he JOpera Stack W MI Delete All Delete Terminate Suspend Resume Then El af ASYNCHProcessSupplier 3 Moo Wei Se af ASYNCHSetup 1 Moo af ASYNCHSubProcessSupplier 3 lso Is BE ASYNCHSubProcessSupplier 2 Figure 2 14 The JOpera Stack v
58. iew working together with the Instance Navigator Advanced Debugging Support More low level details about the progress of the execution can be seen in the Kernel Memory Inspector view which shows a table with all parameter values and can be searched by typing a parameter name in the Filter box or filtered interactively by clicking with the mouse on the interesting processes and 12 2 5 EXAMPLES JE OSEA Properties ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 ws SodiumTestServices Test asmx Test_Reverse 1 fine Cardin Tarna Tack nem Tack Minimos Filter Test Reese n 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ws SodiumTestServices Test asmx Test_Reverse 1 0 O Reverse System ENDDT 2006 10 30 17 37 51 265 java lang String ws SodiumTestServ
59. in the visual editor Select the task boxes to see more information about them in the Properties view e My process has finished can I save it All information about a process is preserved in the kernel s dataspace as long as the user doesn t delete it If you have configured the kernel to use persistent storage this information may even survive kernel crashes Starting in JOpera 2 3 2 the freeze command will save the state of the processes in a file e Can I see the execution time of a process Yes make sure you are showing the advanced properties of the process Figure 7 7 43 7 FREQUENTLY ASKED QUESTIONS Create manage and run configurations Configurations Mame New configuration Java Applet 7 Java Application 7 pe JOpera Process DE araumen mi SILE H Common E New configuration Process Mame Ju unit temp converter TT Browse JE Junit Plug in Test is 35 Run time Workbench Input Parameters Value celsius String 23 Apply Revert coe Figure 7 6 Configure a new launch configuration for a JOpera Process 7 4 Questions about Integrating Processes with other applications e Would it be possible to write a script in Perl or other scripting language to start a JOpera process Yes this can be done through the Web service interface Processes are automatically published as Web services and the WSDL for each process is listed on http localhost 8080 wsdl With this you can write a cli
60. ing the following line into the HTML head element Script type text javascript sre http localhost scripts jopera js gt scripta Figure 5 2 Include the widget API in the page header The jopera js script is served by JOpera s embedded Web server 2 Choose which process should be displayed script type text javascript a function Load 1 lt script gt new TaskDisplayer process msg example asynch ASYNCHP rocessSupplier 1 0 body onload load gt lt body gt Figure 5 3 Load and configure the widget 3 Create a div container where the widget will be placed ar div id process gt lt div gt Figure 5 4 Widget container The id of the div element has to be the same as the first argument used to initialize the TaskDisplalyer widget object 5 3 Example Copy and Paste this example HTML code in your page to get started lt head gt lt script src jopera js gt lt script gt lt script gt function load new TaskDisplayer process lt script gt lt head gt lt body onload load gt lt div id process gt lt div gt lt body gt 32 5 4 TASKDISPLAYER API 5 4 TaskDisplayer API There are three ways for creating the Monitoring Widget depending if you want to display all process or only a single process and in this case if you are interested in a particular instance or in all the instances e Display all process
61. ion 44 4466 Su we ee aa HEE EDDY EERE DERE SEE SH 10 3 LR ak eek ew edhe hw wed hee ew i 10 3 1 Upgrade replacement of programs and processes o o o 10 3 2 Extract sub protess siii ss 10 3 3 Inline sub process 22 2 Cm m nn nen 10 4 JOpera Kernel Command Line Reference 0 0 002 ee eee 10 4 1 Starting processes 10 4 2 Deleting process instances soosoo 10 4 3 Listing deployed process templates LL 10 4 4 Undeploying process templates 2 2 2 2 Cm mn nn 11 Lineage Tracking 11 1 11 2 11 3 TATION y raras a Ae EE ee ELLE We s ee r RE SEHK ESS RSS EAH i EL Li ee eRe AR whee i IO non ip eee hee ERE Ee eB aa DIESEN senora aras Li 11 5 3 Pentito sc ss EE REE HH i 11 3 2 Use ol Memoigation 2 0000 20 3 3 e a REE HEHE ER Hs 114 Ve Tee ERR REAR Re A Air It WOO ein E SEEDS EEE Ew ee SS 114 2 Lineage Summary cocos ana ah e EE EE ee we LS Instanco OW s 44 FR RO REESE Re RR RS 1122 lin age Browser ih pla Ei ae a we i Fio PORTER or a AA Ill Developer Reference 12 How to write Service Invocation Plugins 121 12 2 12 3 12 4 12 5 Adapter Wimp oo su des ia atea Example service invocation plugin ee Setting up a new service invocation plugin 2 2 CE En En Identifying Component Types oo wa a a ha Ri The OML Component Type Definition a 12 5 1 Defining System Parameters 2 ee 12 5 2 Editing System Parameters w
62. ion is made between input and output data parameters From the point of view of the service input data is sent as part of the request whereas output data is retrieved as part of the response JOpera also distinguishes between application level data from system level metadata The IJob interface provides access to all of these parameters identified by their name through the following Maps e public Map getInput get input data parameters e public Map getActiveCommand get input metadata parameters read only e public Map getOutput set output data parameters e public Map getSystemOutput set output metadata parameters Note The values for the parameters stored in these maps can be set to any Java Serializable data type 12 11 Threading model JOpera instantiates a new object of the given service invocation plugin class for each service invocation to be performed Furthermore JOpera calls the execute method of the newly created object from within a dedicated thread Therefore since JOpera already handles the multithreaded issues for the concurrent invocation of multiple services the plugin under normal circumnstances should not have to fork off additional threads to perform the invocation 12 12 Example Code for Synchronous invocation void Execute IJob job take the system input parameters Map c job getActiveCommand do something with it set system output p
63. ith the Adapter Editor 12 5 3 System Parameter Types 20 0 eee 59 99 99 60 61 61 63 64 64 64 64 12 12 12 12 13 75 19 19 19 76 76 76 17 18 18 19 19 80 81 Contents 12 6 The ISubSystem Interface a 89 127 The Lob IMief 06 cos eee owe ATL ALL EEG 90 Ma Cono Tow dpi lt A EES 91 12 8 1 Synchronous Service Invocation aooo e e os 91 12 8 2 Asynchronous Service Invocation 2 2 2 m mann nn 91 12 9 Failure detection gt ie nn ER EE enden niet 91 210 Data fow BI kw a PRA ALLA LA 92 12 ARTO TIO os a te ee RE eR ORE HS Ew ww AR N 92 12 12Example Code for Synchronous invocation 2 2 Emm e e e 92 12 13Example Code for Asynchronous invocation LL 93 12 14Example Code for partial result notification 22 2 2 2 CE Emm 94 12 15Example Code for progress notification 2 2 2 2 CE mm nn 94 12 16Example Code for safe streaming intermediate output 2 2 2 2 nm m nn 94 12 17Example Code for the Signal Method 94 13 Component Type Reference 95 RI AAA 96 13 2 Asynchronous SOAP Message Routing CC a a 97 13 3 Asynchronous Local Messaging aoaaa 97 Tee DELIO lt il a LR a 97 13 5 Condor JOD SUDIO a a a a a Ka Li 97 OI iii LARA 97 13 7 JOpera Delayed ECHO one 97 be ELLI UNG Dowie 2 u 208 2 0 005 eek ee a eG Cee Bowes SERRE EES S 97 13 9 Java method invocation a 3 Kan a e666 dd bee eed ede han 97 I NIT i Bee a a a ih a Re hin 98 13 11Paramete
64. ivators are thus both set to Finished Task1 If both tasks were supposed to be executed in parallel upon start of the process without depending on Task1 the activators of both would be left empty meaning that both tasks are to be executed when the process starts executing 93 9 JOPERA VISUAL COMPOSITION LANGUAGE REFERENCE Figure 9 2 Parallel task execution 9 1 4 Flow In general any Directed Graph can be used to specify arbitrary dependencies between a set of tasks Note You can also work with cyclic graphs as long as you update some of the activators on the merging points not to introduce deadlocks See Section 9 3 on page 55 for more information on how to do this Figure 9 3 Arbitrary Flow task execution Dependencies can be drawn on the Control Flow view Figure 9 3 JOpera will automatically translate them into a set of activator expressions like in the following Note You can also manually change the activator by selecting a task and editing the corresponding property 9 2 Branching Control Flow Patterns 9 2 1 Parallel Split A point in the process where a set of activities can be executed in any order even in parallel Since the activators of both B1 and B2 fire when task A is finished they will be both executed in parallel 9 2 2 Synchronization A point in the process where multiple independent paths A B must be synchronized before execution continues with C 94 9
65. ld be implemented e The second extension defines the system parameters that describe how the service type should be invoked This information is described in an OML file that should be packaged with the plugin 1 Add a ch ethz jopera core model extension 2 Right click it and add a new model element 3 Browse for the OML file which defines the system parameters that will be passed to the subsystem when invoking services of the corresponding type We will describe the structure of this file in Section 12 5 on page 87 E jop xml Mt ch ethz jopera testsubsystem X i 20 Extensions ch ethz jopera testsubsystem plugin xml FE All Extensions Extension Element Details E ch ethz jopera kernel SubSystem Set the properties of SubSystem x Subsystem class ch ethz jopera subsystems TESTSubsystem ch ethz jopera core model X data test oml model SID TEST gt Body Text Overview Dependencies Runtime Extensions Extension Points Build plugin xml build properties Figure 12 2 Extension provided by a Subsystem plugin 12 4 Identifying Component Types JOpera manages a list of adapters that are provided by its plugins as shown in Figure 12 3 Each adapter is identified by the name of the component type it provides to the modeling environ ment The name of the component type should also match the Subsystem ID SID used to register the adapter code implementing the ISubSys
66. lemented with the most suitable technology e g an XSLT transformation or a Java snippet For execution the JOpera Visual Composition Language is compiled to Java code To ensure the required level of scalability reliability and flexibility such code is dynamically loaded into a runtime container the JOpera kernel The flexible architecture of the JOpera kernel can be deployed in different configurations stand alone embedded into other systems e g application servers or development tools like Eclipse The same architecture can also be replicated across a cluster of computers to handle the concurrent execution of a large number of composite services The JOpera distributed kernel can also monitor its internal behaviour and configure itself automatically in order to provide an optimal balance between providing good performance and efficiently using the available resources 1 4 About this manual This manual contains basic information on how to work with JOpera including several step by step tutorials with many screenshots and a reference to the most important commands and configura 1 5 REVISION tion options Comments and contributions on how to improve the manual and JOpera are welcome feedback jopera org Note Given the rate at which the system s user interface changes it is not always possible to keep the screenshots of the documentation consistent with the latest version of the actual software 1 5 Revision Id jop
67. lifier 2 system condor CONDOR 1 0 Figure 12 3 List of Component Types declared by JOpera adapters 12 5 The OML Component Type Definition A OML component type definition file can actually store multiple definitions provided by the same adapter plugin 12 5 1 Defining System Parameters A component type models a certain service invocation mechanism using a set of input and output parameters The following example models the invocation of UNIX command lines and the invocation of RESTful Web services through HTTP lt OCR VER 2 0 gt lt COMPS gt lt COMP ABSTRACT false OID CT_UNIX NAME UNIX DESC Run an Operating System Shell Command us lt INBOX gt lt PARAM OID INPARAMUNIX1 TYPE Text NAME command DESC The command to be executed gt lt PAR lt PARAM OID INPARAMUNIX2 TYPE File Advanced NAME shell DESC The shell to be used opti lt PARAM OID INPARAMUNIX3 TYPE Text NAME stdin DESC The standard input to be piped into lt PARAM OID INPARAMUNIX4 TYPE Enum buffer lines both Advanced NAME mode gt lt PARAM gt lt INBOX gt lt DUTBOX gt lt PARAM OID OUTPARAMUNIX1 TYPE String NAME stdout gt lt PARAM gt lt PARAM OID OUTPARAMUNIX2 TYPE String NAME retval gt lt PARAM gt lt PARAM OID DUTPARAMUNIX3 TYPE String NAME stderr gt lt PARAM gt lt PARAM OID OUTPARAMUNIX4 TYPE String NAME Output gt lt PARAM gt lt OUTBOX gt lt COMP gt 87 12 HOW TO WRITE SER
68. n Perspective is used to model and define your processes The Monitor perspective is used to watch the processes as they run These perspectives give you access to a set of views that complement the Editor of JOpera s OML files In the Design Perspective these views include e the JOpera Navigator manage your OML files e the Outline view and edit the structure of an OML file e the Properties set properties of selected JOpera elements e the Problems see JOpera errors and warnings updated in real time e the JOpera Library reuse your processes and programs In the following we introduce each of these views After you become familiar with them you can open some examples and start using JOpera Otherwise you can skip ahead and try some of the tutorials to quickly become productive with JOpera JOpera Navigator The JOpera Navigator gives you an overview of all the JOpera projects you have in your workspace and all OML files therein Right clicking in this pane lets you create a new JOpera project or a new OML file It also enables you to import WSDL descriptions of Web Services or JAVA classes Double clicking on any of the OML files will open the corresponding JOpera Editor 2 GETTING STARTED 12 JOpera Navigator gt as v test IEuro omi ITempConwerter oml Temperatureservice oml WholsService aml ZipService oml Figure 2 5 The JOpera Navigator Outline The outline gives you a brief overview ove
69. nal did not affect the running job return State RUNNING 94 13 Component Type Reference This chapter contains reference information about JOpera s component types and the corresponding subsystems plugins 95 13 COMPONENT TYPE REFERENCE 13 1 Overview Component Types BPEL Section 13 4 on page 97 Native CONDOR Section 13 5 on page 97 ch ethz jopera subsystems condor Plugin DELAYEDECHO Section Lil on page 97 ch ethzjopera subsystems streamlibrary Plugin ECHO Section 13 6 on page 97 Native HTTP Section 13 8 on page 97 Native INVOKE Section 13 14 on page 98 JAVA METHOD JAVA SNIPPET ch ethz jopera subsystems router Plugin Section 13 9 on page 97 ch ethz jopera subsystems java Plugin Section 13 10 on page 98 Native MSG Section 13 3 on page 97 Native PARAMETERVIEWER Section 13 11 on page 98 ch ethz jopera subsystems parameterviewer Plugin RECEIVE Section 13 2 on page 97 ch ethz jopera subsystems router Plugin REPLY Section 13 2 on page 97 ch ethz jopera subsystems router Plugin SQL Section 13 12 on page 98 Native SSH_CMD Section 13 13 on page 98 ch ethz jopera subsystems ssh Plugin SSH_SCP Section 13 13 on page 98 ch ethz jopera subsystems ssh SSH_TUNNEL Plugin Section 13 13 on page 98 ch ethz jopera subsystems ssh Plugin UNIX Section 13 15 on page 98 Native WSIF Section 13 17 on page 98 ch ethz jopera subsystems
70. nced gt gt cn Figure 3 2 Creating a new OML file Enter an appropriate file name halloworld oml in this case and click on the Finish button 17 3 HELLO WORLD TUTORIAL 3 3 Setting up the Hallo World Program Before we can create a composition we need to define what are the components In JOpera we need to create some programs that will be later connected into a process To do create the Hallo World Program A halloworld oml X Ta Overview Processes Programs Figure 3 3 Adding a new Program 1 Click on the Add button in the Programs overview 2 Click on the Edit button to edit the NewProgram TEO JOpera Navigator 23 A el a Haloworld oml X I IA A Overview D test MM halloworld oml v Processes v Programs BE Outline 2 N_ Ta L gt Processes 0 Overview lt Programs 1 A a a NewProgram 2X Problems 3 _ Properties JOpera Library aS gt Access Methods 0 1 error O warnings 0 infos Filter matched 1 of 2 items gt Parameters 0 Description Resource In Program NewProgram contains no Access Methods halloworld te Figure 3 4 Editing a Program Note JOpera has found out that it cannot run this program and is reporting this in the Problems view We will fix this in a minute Rename the program to HalloWorld The program is going to receive an input string and produce an ou
71. nd then click the New button This will create a new launch configuration to execute a process Choose the process which is to be executed by pressing the Browse button and the select the process in the new dialog Now complete the launch configuration by filling in the values for each of the process input parameters The process will be started as soon as you click on Run Create manage and run configurations w Configurations Name New_configuration Java Applet 7 Java Application A e JOpera Process Arguments Start Options E common p New configuration Process Name Ju JUnit temp comwerter CBSE Ju JUnit Plug in Test ne Run time Workbench Input Parameters Value celsius String 23 Apply Revert ce Figure 2 11 Configure a new launch configuration for a JOpera Process 10 2 4 BASICS 2 4 6 Monitoring Processes At run time in the Monitor Perspective you have also access to additional debugging and monitoring views e the Instance Navigator see what processes are running e the Properties and the Parameter Viewer see what are the values of selected parameters the JOpera Stack check which process is calling this process e the Kernel Memory Inspector look at the entire state of the running processes for advanced users e the Kernel Console command line development interface to JOpera s execution kernel These allow you to check the progress of a running pro
72. ng it with a Control Flow arrow Select the arrow and change its Dependency in the Properties View from Finished to Failed ES Properties X Y EE WO Property Value Design Dependency Finished Router Finished Figure 7 4 A Control Flow Arrow represents different kinds of dependencies 7 3 Questions about Running Processes e How do I start a process In general processes are started with Eclipse launchers in the Run menu by selecting the JOpera Process launch configuration type However a process can also be quickly started from the overview page of the editor by clicking on the Start button Overview Processes g SimpleProcess Figure 7 5 The quickest way to start a process is to click on the Start button e How do I set the input parameters of a process This information is entered as part of the launch configuration in the Arguments tab Thus different configurations can be stored for the same process e How do I modify a compiled process It depends if you want to keep the old version If so you will need to rename the process and compile it with a new name Otherwise just save the modified changes and the new version of the process should be deployed over the previous one e How do I check whether a process has finished How do I see the results Go to the JOpera Monitor perspective select the process instance in the Instance Navigator view and you should see its current state
73. ng the Process 4446 si eed EOE REE e EEE OO EERE EES 4 7 Draw Data Flow Connections aooo AS Compilation oi the Process se sadia 6645 ee ew LE ee HES 4 9 Executing and Monitoring the Process 5 Monitoring Widget Tutorial Sb allea 9 2 Adding a Monitoring Widget nenn Mae Wes TENE WON MH KF et NNN NOQA ip w oD o O 15 17 17 17 18 21 22 23 23 23 23 24 24 20 20 20 20 31 31 31 32 111 Contents od TaskDisplayer API aa eR KEES EERE AA nee 33 Java Services Tutorial 35 A o lt a n Lie 35 6 1 1 Calling Java Snippets from a JOpera Program LL 35 6 1 2 Testing the Java BMIphet i c e cos seess E ed eee e Eas 39 VI re we a ER ES 36 fel Importing Java Classes a en a ah inne 36 6 2 2 Calling Java Static Methods 36 bi DIRI siii eh ia oe EEE HEE 36 6 3 1 Working with Objects as parameters 0 36 Reference Manual 39 Frequently Asked Questions 41 7 1 General Questions lt il RR na a 41 7 2 Questions about Developing Processes aoa a a e e a e a 41 7 3 Questions about Running Processes 43 7 4 Questions about Integrating Processes with other applications 44 7 5 Running JOpera as a server kG ee a a 45 19 Other questions 2 54 64 Aw oe eee a AAA 45 da DUDENN ee eS Beten 46 How To 49 8 1 How to publish a process as a Web service oaoa oaoa a a a 49 e Howto debug a ld task ici dae EKER a 49 8 3 How to display a parameter in a web browser
74. o unlike the BPEL Wait command this component will not keep a thread busy sleeping so it should not be used for load testing of the engine 13 8 HTTP URL Download 13 9 Java method invocation This component type allows to invoke local Java methods from Java classes that are dynamically loaded into the JOpera engine VM Use the Java Import Wizard to automatically generate programs that call the Java methods The classpath parameter stores a list of URLs that make up the class path used to search for the method to be called The method identifies the method signature including the fully qualified name of its class and the parameter types The arg parameter maps the input parameters of the program to the method s parameters It lists the names of the program input parameters in the order in which they should be passed to the method The instance parameter is used to pass the object on which the method should be called if it is not set the method can be either a static method or a constructor 97 13 COMPONENT TYPE REFERENCE 13 10 Java snippets The script parameter should contain java code that fits inside a Java method Input and Output parameters are implicitly declared as local Java variables Uncaught exceptions will cause the task to fail 13 11 Parameter Viewer Sending data to the input input system parameter of this component type will display it in the Parameter Viewer See the parameterviewer oml example for more informa
75. onstructs a very important feature of the JOpera Visual Composition Language consists of describing how to compose services at the level of abstraction represented by their interfaces Thus the description on how to compose the services is independent of the actual low level protocols and mechanisms that are used to perform the actual service invocation Abstracting the interface of a service from its access mechanism helps to generalize the scope of the JOpera composition language and system well beyond Web services This way the user can freely choose to compose the most appropriate kind of services in terms of performance reliability security and convenience Likewise the composition language is not affected when extending the underlying system to support other kinds of services In other words JOpera is future proof and can readily support future revisions of today s Web services standards Thanks to this flexible approach it is possible to unify composition and mediation aspects within the same language In a typical service composition scenario Web services published by independent organizations are to be composed in a bottom up fashion In general a mismatch between these services it is to be expected With JOpera in order to solve the problems due to different data representations or incompatible interaction styles a service fulfilling the role of mediator can be added in a straightforward manner Furthermore such mediator can be imp
76. ool Auto Complete Show All Parameters Show InboxParameters Show System InboxParameters gt Create New Input Parameter Figure 4 6 Displaying the Parameters of a Process A Temperstureservice oml X getTemperature getlemp retum getlemper ture Overview Process getTemperature View ControlFlow View DataFlow Figure 4 7 Complete Data Flow of the Sample Process Errors or failures will be colored red In order to inspect the result of the execution of either a task or a process simply click on the box and check out the properties view The properties view will show you the result or possible error messages Alternatively you may want to open the Kernel Memory Inspector view by selecting it in the Window Show View menu The Kernel Memory Inspector shows you all data in the kernel s memory This in cludes the input as well as output parameters of the processes and tasks the state of each process and task and more The state of each process and task is also highlighted by a the colors blue red and yellow indicating that a process or task has finished successfully failed or is still in progress respectively 27 28 4 WEB SERVICES TUTORIAL Create manage and run configurations Configurations Name tutorial Arguments Start Options ES common li JOpera Process Process Mame getTemperature Browse Input Parameters Parameter Type Value String 47906 Apply Revert
77. ort The second part is a more detailed explanation of the message if one was found and where the message occured 10 1 4 Known Limitations The WSDL Import Wizard has limitations as the numbers of different WSDL files are theoreticaly endless and we could not cover every eventuality The importer can only be made more powerful with feedback from user with WSDLs that crashed or were not satisfactorily imported Some of them have already been found and known limitations are listed here e Schema import chain There is a problem when more than one schemes are defined in a WSDL file and one or more is referencing another one The referenced message part will not be found 61 10 FEATURE REFERENCE new Import WSDL Import WSDL into JOpera There were some warnings and errors while reading the wsdl Warnings and Errors n exception happened while importing the WSDL File Something wrong happened while creating the orl File The Element Type of parameters was not found Details WORM The Element Type of parameters was not found In ch ethz jopera subsystems ws importws part soap SoapPart processElementDecl Figure 10 3 Viewing the Warnings and Errors and will be defined as a string The responsability will then fall onto the programmer to find the right format for the parameter Leaves only output format The Leaves Only output format changes the way the output parameters are mapped to the output fields
78. owser It is available since JOpera v2 3 6 This tool may be integrated and executed within any HTML web page by embedding a chunk of code within the page STOF msg_example asynch ASYNCHProcessSupplier 1 0 0 Running ComputePrice ReceiveOutcome ReceiveRFP RegisterwithRegistry SendBackProposal mit Running ComputePrice ReceiveOutcome ReceiveRFP RegisterwithRegistry SendBackProposal mit Running ComputePrice ReceiveOutcome ReceiveRFP RegisterWithRegistry MESS SendBackProposal Figure 5 1 Monitoring a Running Process The figure above shows an example where each instance of the msg_example_asynchASYNCHProcessSupplier 1 0 process is described by the states of their tasks Each task has a name on the left and a colored rectangle at the right The color that may change over time defines the current state of the task On the top there is a STOP button that when clicked terminates the execution of the monitoring widget which may further be restarted by clicking again on the same button Note Clicking on the STOP button will not stop the execution of the process but only pause its monitoring by the widget the Stop button can be hidden using CSS 5 2 Adding a Monitoring Widget In order to use the Monitoring Widget you need to add some lines of code to your HTML Web page l 5 MONITORING WIDGET TUTORIAL Note Multiple Widgets can be added to the same page 1 Load the widget API by add
79. pdate site and push the Next button 4 It will take a while until the features list is updated From the updated list select JOpera for Eclipse and Graphical Editing Framework 3 0 1 Then click on Next Accept the license agree ments on the next page for both features If you do not have write permission in the Eclipse directory press the Add Site button and point to a location where you have write permission Make sure you selected the newly added site In any case proceed by hitting the Finish button and press the Install button for each feature as soon as prompted Install Install Location Choose the location where the Features will be installed Features to install Available sites Ll Graphical Editing Framework 3 0 1 u Documents and Settings Thomas Desktopleclip ESE Ll Jopera for Eclipse 1 0 5 Required space OKB Free space 609025KE lt Back Cancel Figure 2 3 Adding a new installation Site 5 You will now be asked if you want to restart Eclipse Press Yes and you should be all set as soon as Eclipse has been restarted 6 That s it Enjoy JOpera for Eclipse 2 1 1 System Requirements The JOpera for Eclipse currently requires Java JDK 1 5 and a working installation of Eclipse 3 3 or 3 4 Ganymede with the GEF plugin the Graphical Editing Framework There are no specific requirements regarding operating system You may use it on any OS where the Java JDK as well as Eclipse work It has succes
80. pera you can import standard compliant WSDL documents and immediately invoke the Web service from a process without having to provide additional information Control flow BPEL has several redundant constructs given its origin which mixes a hi erarchical nested block process modeling approach with a flow graph based process modeling approach And even with this richness in the syntax it has been shown that it lacks expressivity regarding several important workflow patterns JOpera has a much simpler graph based model that is even more expressive 45 7 FREQUENTLY ASKED QUESTIONS Data flow BPEL uses a low level imperative model based on assignements between vari ables where each data transfer must be scheduled manually by the developer JOpera uses a high level declarative or functional approach where it is enough to model a graph of data flow edges and the system takes care of copying the data at the right time Nesting Although BPEL supports nesting with scopes inside a process every interaction between different processes is done through a Web service interface Thus it becomes difficult for a BPEL engine to know whether a process is calling another process on the same engine or it is invoking a remote Web service Thanks to its sub process construct JOpera processes can efficiently call or spawn other processes without having to pay the overhead of the Web services stack Syntax BPEL is XML and most vi
81. process or program is executed when the Delete this Version button is pressed Tagging The tagging of the entity currently displayed is done by mean of the combo menu as shown in Figure 112 Outline The outline in JOpera design mode has been slightly extended to group all same entities with different version numbers together under their common entity name as seen in Figure 11 3 19 11 LINEAGE TRACKING Process ProcA 1 0 General Information O Abstract C Comment M Published C Subprocess Flow Control Name ProcA Author Version 1 0 y Stable Delete this Version Unstable Description This process compl Deprecated by calling ProcB and Inc Figure 11 2 Tagging an entity w Processes 2 y gf ProcA 2 af Version 1 0 b of Version 1 1 y Y ProcB 1 b of Version 1 0 amp Programs 2 Figure 11 3 Outline view 11 2 database setup For the Lineage module to work in particular the memoization lineage browser and logger it is necessary to set up a PostgreSQL database The database should be accessible from the host where JOpera runs in case it is not local This means that the right host authorization line should be present in the pg hba conf PostgreSQL configuration file like for instance the following one host all all 192 168 1 0 24 md5 Which allows a database access with md5 authentication for a JOpera client that is on the subnet 192 168 1 0 24 Additionally a us
82. protocol If the WSDL file is stored offline on the Computer it can also be entered directly or through the Browse Button situated to the right of the entry field 59 10 FEATURE REFERENCE e Target OML File This is where the generated OML file will be saved to Every time the URL changes a default destination will be generated by the wizard It can be changed afterwards to accomodate the needs of the user Furthermore there are some options that have to be selected e Connection Type The Connection Type defines what kind of operations should be extracted from the WSDL file Depending on the type different JOpera adapters will be added to the program At least one connection type has to be selected or there will be no operations to import e Input Format If a program that is generated from an operation needs complex input parame ters two different input scheme can be used The Leaves Only mode will generated an input field for every parameters that can contain a value indipendent on the structure of the input message It is then the responsability of the different adapters to handle the recreation of the complex type The With Packer Mode on the other hand will generate one input field for every input parameter in the message indipendent on the type of the input simple or complex The adapters have to create packers that will create the complex type given the underlying input parameters The packer structure
83. r Eclipse is a complete rewrite of JOpera for Windows as a set of Eclipse plugins It not just a port of JOpera to run on Windows Linux and Mac but also a significant improvement adding a lot of new functionality Here are some examples e Support for editing multiple source files e Support for editing different versions of the same process e Automatic background model checking errors and warnings are listed in the problem view as you work e Automatic incremental recompilation and transparent redeployment of processes e The JOpera process execution kernel is embedded into the Eclipse workbench and is started automatically e A fully fledged application server is also embedded so that processes can be published as Web services with one mouse click Section 8 1 on page 49 e You can add your own service invocation adapters and package them as Eclipse plugins In addition to Web services through SOAP HTTP and WSIF plugins are available to efficiently invoke Java snippets Java classes remote UNIX commands through SSH XML transformations XSLT XPATH SQL queries sent to any JDBC database large Job submissions to clusters managed by Condor e Examples can be added to the workspace using the New gt Examples menu command of Eclipse Section 2 5 on page 13 e You can more easily build your own program library and also reuse the standard library of programs that come with JOpera e JOpera for Eclipse is agile it now include
84. r Viewer lt a Re EOE EOS REDE SES 98 LAR AA oe eS REG ERE EHO EOS Ow eee ee ee es 98 13 13Secure Shell Operation 98 13 145 ynchronous SOAP Messaging u a 00 6 40 eee a ERE es 98 13 15UNIX Legacy Applications 2224 2 2 oz CURED n A ES 98 19 16 XML Tranelormati nsS ssa ads a eee eee eee GER ea e 98 13 17Web Services Invocation Framework nn 98 14 How to write Documentation 99 TLI IR oros ae su RE 99 14 2 XML Reference 2 4 u 0 0 0 u u ad AAA 99 vi 1 Introduction Welcome to JOpera Process Support for more than Web Services With this system you can rapidly build processes which interconnect many different types of software components including but not limited to Web Services 1 1 What is JOpera for Eclipse JOpera targets developers of Service Oriented Business Applications and provides them with tools for rapid service composition It includes a visual modeling environment a light weight execution engine and also powerful debugging refactoring tools which natively support the iterative nature of service composition Service composition models in JOpera are defined at a higher level of abstraction than traditional BPM BPEL languages and cover both architectural structural aspects as well as behavioural flow ones JOpera is built as a collection of plugins for Eclipse thus having great potential for further extensibility and integration with other SOA tools 1 2 What s new in JOpera for Eclipse JOpera fo
85. r everything contained in an OML file This includes the processes and their parameters tasks and views as well as the programs and their parameters and Adapters Double clicking on either of these will open a detailed view in the Editor Right clicking in this pane lets you add and delete various elements Processes Programs Parameters Activities SubProcesses to the OML file nz Outline X Processes 1 a temp_converter Parameters 21 celsius String Fahrenheit String Tasks 1 e Views 2 Ry ControlFlow Fa DataFlow I Programs 2 CtoF Access Methods 11 CtoF SOAP 12 Parameters 2 temp xs int return stink 4 FtoC Figure 2 6 The Outline View Editor The Editor lets you have a more detailed view on the OML files and lets you edit them You can in particular add new processes populate them with tasks add or remove parameters and define the data and control flow graphs by switching among the various pages Problems and Properties Views The Problems View shows if there are any problems in the process you are currently working on The process will not run as long as there are errors in it In some cases JOpera provides a Quick Fix Clicking on the Properties View will show any defined properties of the object selected in the graphical part of the editor 2 4 BASICS m ITempConverter oml 3 A Overview Il i Programs a temp_converter a CtoF a FtoC
86. ranch gets activated possibly concur rently the activity following the merge is started for every activation of every incoming branch This is exactly the semantics of the OR in the activator associated with task D 9 2 8 N out of M Join This example shows how to merge 2 out of 3 paths The execution of D will take place if any pair out of the triplet task A task B task C has finished 9 3 Loops 9 3 1 Infinite loop An infinite loop can modelled by setting the activators of tasks such that they in turn depend on the previous task 313 9 JOPERA VISUAL COMPOSITION LANGUAGE REFERENCE Figure 9 4 Infinite loop executing three tasks sequentially Note To avoid a deadlock the clause OR TRUE should be added to one of the tasks activators In case of three tasks Task1 Task2 and Task3 which are supposed to be executed sequentially in a loop as depicted in Figure 9 4 the activators are set as follows The activator of Taskl expresses that Task1 is either executed after Task3 has been finished Fin ished Task3 or upon start of the execution of the process TRUE 9 3 2 While loop Modelling a while loop can be done by making use of the condition guard i e the COND attribute the condition to remain in the while loop is the same condition the COND attribute should be set to In case of a while loop where the control flow should remain in the body of the while loop as long as the counter variable
87. riginal Price Mel wi de E Integrate ConvertedFrice Converted Price Original Price Stock Quote Convert Full Figure 10 8 Autoconnect Example after es get Quote get reat l I Connection Tool y Delete Auto Complete gt Price Show System InboxParameters Show System OutboxParameters Refactor Extract to Subprocess Switch Program Figure 10 9 Context Menu Selection 10 3 REFACTORING AON Program Browser Search Text Matching Items i getQuote getRate Qualifier test_demo getQuote 2 ex_demo getQuote 3 test_demor getQuote test_demo_orig getQuote Care CD Figure 10 10 Program Browser 800 Refactoring Switch Process Program refactoring This refactoring substitutes a Process Program _ Switch all occurences in file subProcesses task referencing same process program Switch all occurences in project subProcesses task referencing same process program Switch all occurences in workspace subProcesses task referencing same process program Figure 10 11 Refactoring Wizard A 67 68 10 FEATURE REFERENCE rn m n r_ _ Default Currency USA n n Currency Default Currency a E Integrate ConwertedFrice Figure 10 12 task and constant selection E l Default Currency USA l n a Po Currency Default Currency Connection Tool E Delete Ali
88. rvice operation 1 Select the operation and click on Test 2 A Test client process will be generated automatically click on Start to run it and call the Web service operation e How do I make a task start after another has finished Go to the ControlFlow View of the process which contains the tasks and connect the tasks with an arrow 3 X 9 4 SecondTask SecondTask Overview Process NewProcess 1 0 controlrlow DataFiow Rent Figure 7 2 Add a control flow dependency Now the Second task to which the arrow points to will be started after the First task from which the arrow begins has finished e How do I draw an arrow No need for dragging Instead follow these steps 1 Make sure you have selected the Connection Tool in the toolbar Ty Se sie ab He of te Ar gt Figure 7 3 The Connection Tool is the first one 2 Click on the box you would like the arrow to start from The box should now be selected 3 Click on the other box the one you would like to connect with the previous one The arrow should be now there If the arrow didn t appear there may be a reason for that make sure you are not drawing it against the direction of the data flow 42 7 3 QUESTIONS ABOUT RUNNING PROCESSES e How do I run two tasks in parallel Make sure there is no control flow arrow between them e How do I create an exception handler Connect the task handling the exception to the task causi
89. s visual refactoring and regression testing tools 1 INTRODUCTION e JOpera for Eclipse integrates with the rest of the tools that run on the platform e g CVS WTP TPTP JOpera for Eclipse is backwards compatible with JOpera for Windows v1 71 and below However JOpera 1 71 is not upwards compatible with JOpera for Eclipse 1 3 About JOpera for Eclipse Web services offer a standards based approach to address many interoperability issues arising when composing distributed software systems out of reusable services Thanks to the SOAP protocol and WSDL interface description language an increasingly large number of basic services are being published on the Internet Clearly it becomes important to find the right composition abstractions in order to build value added services out of the aggregation of basic ones Complementing existing approaches based on the XML syntax e g BPML BPEL we have designed a visual syntax for a service composition language Thus the data exchanges between the services data flow their order of invocation and the necessary failure handling behavior control flow can be all specified with a simple graph based visual syntax As opposed to an XML based approach a visual language can greatly enhance the understandability of the composite system and provide the foundation for building rapid service composition tools such as the JOpera for Eclipse system Among nesting recursion iteration and reflection c
90. sfully been used on Windows Linux and MacOS X platforms 2 2 Running JOpera for Eclipse JOpera for Eclipse is started by running Eclipse All you may need to do is switching to one of the JOpera perspectives In case you need to switch to the JOpera perspective manually you can do so by clicking on Open Perspective and then on Other in the Window menu Then choose either JOpera Design or JOpera Monitor in the Select Perspective dialog 2 3 UPGRADE Select Perspective xi Ea cvs Repository Exploring Hy Debug y Java default Java Browsing Ye Java Type Hierarchy i i Opera Design E JOpera Kernel no JOpera Monitor Plug in Development Resource 50 Team Synchronizing X XML cancel Figure 2 4 Switch to a JOpera perspective 2 3 Upgrade To keep your JOpera for Eclipse up to date just use the Eclipse Update Manager regularly Make sure to do a full rebuild of your workspace after upgrading 2 4 Basics 2 4 1 Service Composition with Processes JOpera is a tool to build composite systems out of components These components can be of many different types including Web Services UNIX applications Windows applications Java scripts and many others The structure of such composite system is defined with a Process which defines the control and data flow between the various components 2 4 2 Design Time User Interface JOpera basic interfaces comes with two perspectives Design and Monitor The Desig
91. stem which can be accessed by JOpera using one of the following protocols UNIX pipes stdin stdout for standard UNIX applications SOAP messages for Web services Java local method invocations for Java classes and Java snippets SSH for remote UNIX command line applications JDBC to send SQL queries to a database directly from a process You can download additional JOpera plugins to extend the set of supported service invocation mechanisms You can even write your own adapters Al 7 FREQUENTLY ASKED QUESTIONS e What is a subprocess A subprocess is a task which represents a call to another process e What is the JAVA SNIPPET component type This is how you can embed snippets of Java into a process Any Java code that fits into a method will do What happened to the JAVASCRIPT component type As this was a big source of confusion we renamed it to JAVA SNIPPET in JOpera for Eclipse How much work does it take to test a Web service with JOpera After importing its WSDL just 2 mouse clicks i GoogleSearch oml X Tom Overview v Processes v Programs Test_doSpellingSuggestion 1 0 5 doGetCachedPage 1 0 4 doGoogleSearch 1 0 doSpellingSuggestion 1 0 ListFrom_DirectoryCategoryArray 1 0 4 ListFrom_ResultElement rray 1 0 gt sar Unpack_DirectoryCategory 1 0 1 E 2 Unpack_GoogleSearchResult 1 0 4 Unpack_ResultElement 1 0 Figure 7 1 Quickly write a client process to call a Web se
92. sual BPEL editors sadly remind developers of this as they provide an editing environment which is tightly coupled with the underlying XML syntax JOpera keeps the XML under the hood and provides a true visual environment for Web service composition where developers can concentrate on specifying the flow between tasks at a high level of abstraction without having to worry about the underlying XML syntax Library BPEL standardizes as language elements several activities that should really belong in a library e g timeouts JOpera provides a rich and extensible library of reusable services which cover important functionality e g timeouts XML data transformation cancellation patterns without affecting the language Snippets BPEL lacks native support for embedding code snippets and BPELJ a contro versial extension to the standard has been proposed to allow this JOpera supports Java snippets natively and does not require any extension to the process modeling language in order to support other snippeting languages 7 7 Troubleshooting Why has my process failed A process fails if at least one of its Tasks failed and there was no exception handler defined for it An Activity fails if its Program returns with a non zero return code or in case of a Web service call if a SOAP fault message is received A Sub Process fails if the process it called has failed After I save a process its name doesn t appear in the Instance Navigator
93. t does not contain any tasks and the input and output parameters are disconnected meaning that they need to be connected in the data flow We will fix both problems in the next two sections 4 6 Populating the Process After having created the process it s now time to populate it with tasks In order to do this you can simply drag programs from the Outline view and drop them on the data flow of the process you wish to populate In the case of this tutorial the get Temp program is added to the process 4 7 Draw Data Flow Connections In order to draw the data flow connections you first have to switch to the Data Flow view of this process Then the input and output parameters of the process need to be displayed Displaying the parameters can be done by right clicking on the process boxes and selecting Show All Parameters in the context menu As soon as this has been done the input parameters of the process need to be connected with the input parameters of the task The same is true for the output parameters the output parameters of the task need to be connected with the output parameters of the process To do this right click in the view and choose Connection Tool in the context menu Now simply connect the appropriate boxes by clicking on them In case of this simple process the control flow is defined implicitly 4 8 Compilation of the Process Compilation of the process is simply done by saving the OML
94. tasks In this case it is the responsibility of the service invocation plugin to notify JOpera whenever it detects that the service has completed its execution Since the execute method has already returned the plugin must use its own thread to run the following code job setState State FINISHED job notifyFinished This code will inform JOpera of the asynchronous completion of the job representing the service invocation 12 9 Failure detection It is the responsability of the plugin to provide the necessary logic to detect whether a service invo cation was successful To do so a successful invocation should use the following code job setState State FINISHED If a failure occurred e g a timeout or any kind of exceptional condition has been detected JOpera can be notified with the following 91 12 HOW TO WRITE SERVICE INVOCATION PLUGINS job setState State FAILED Additional information about the failure e g describing its cause with some error messages can be stored in the plugin specific system output parameters 12 10 Data flow mapping In addition to transferring control the service invocation adapter is responsible for transferring data between JOpera and the service provider for the specific kind of service The subsystem is responsible for implementing the required encoding decoding of the data JOpera structures the data parameters exchanged with the subsystem as follows First of all a distinct
95. ted in Figure 11 5 Execution Settings Memoization Disabled Deterministic C Cache for s Time Out 0 Figure 11 5 Memoization parameters The memoization settings are on the first line of the panel which is only present if the jopera ui lineage plug in has been installed We see in Figure 11 5 the case were memoization has been switched off for the current process by ticking the Disabled radio box It is interesting to note that each process or program has got its own memoization settings so a fine granularity of which entities have their execution logged to the database for memoization is possible Figure 11 6 shows the case where memoization is turned on This is done by ticking the Deterministic radio button on the panel Execution Settings Memoization Disabled Deterministic Cache for s Time Out 0 Figure 11 6 Memoization turned on In case a process or program is not fully deterministic but has an execution that can be seen as deterministic inside a certain time window it is also possible to use the memoization module Such 17 11 LINEAGE TRACKING a process could be some web service returning information that has a certain time of validity like a stock quotation or an exchange rate service As a web service or another service type having a non negligible latency it can be interesting to cache its result during the validity period to increase the system performance The Figure 11 7 sho
96. ted in the JOpera OML project e the j button will add the selected chosen methods to the available ones e the jj button will add all chosen methods to the available ones e the button will add the selected available methods to the chosen ones e the button will add all available methods to the chosen ones 60 10 1 WSDL IMPORT WIZARD new Import WSDL Import WSDL into JOpera The WSDL has been successfully read Choose the operations to import Operations Available Operations Selected Operations 504P12 Drawa mbulancePositions 504P12 Drama mbulancePositionsTest 504P12 DrawRoute 504P12 DrawRouteMap 504P12 GetClosest 5056P12 PaintResponseRange SOAP_Draw mbulancerosikians SOAP DravwAmbulancePositions Test SOAP_PaintResponseRange Figure 10 2 Selecting the different operations 10 1 3 Warnings Errors and Interpretations A lot can go wrong when importing a WSDL file and the different operations Some errors may result in the OML file being empty e g not finding the WSDL file other may result in the OML file having less programs then the number of chosen operations e g the message format of an operation could not be imported To understand what went wrong the user can select next instead of finish and see the different warnings and errors that happened on importing the WSDL file The Panel is separated into two categories The first part is a list of all errors and warnings that happened during the imp
97. tem interface The code of the adapter will be called when a program bound to the corresponding component type is executed by the JOpera engine The adapter code receives the data used to invoke the corresponding service This data is structure according to the corresponding component type definition Note It follows that the component type name and the corresponding Subsystem ID should be unique Additionally also the name of the OML file where the component type is declared should be unique among all adapters that are plugged into JOpera This file name is shown to the user in the Qualifier at the bottom of the Component Type Browser Figure 12 3 Note Versioning Component Types Whereas component type definitions can be associated with a version number it is currently not possible to attach version identifiers to the Subsystem ID Therefore whereas at design time JOpera process models can be bound to multiple versions of a component type all versions will be executed with the same adapter code which typically works with the latest version of the component type and should be kept backwards compatible 86 12 5 THE OML COMPONENT TYPE DEFINITION Adapters CondorAdapter CONDOR pre ADO Component Type Browser Delete Search Text Matching Items Enahle ae BPEL 22 CONDOR ae ECHO 22 HTTP gs HUMAN 22 INVOKE 32 JAVA METHOD 22 JAVA SNIPPET 22 MSG 2 PARAMETERVIEWER ae PEC 22 RECEIVE 2 REPLY Qua
98. tem shell prompt to see if you can reproduce the failure outside of JOpera e Failed Java Snippets report the uncaught exception in the Exception parameter 6 3 How to display a parameter in a web browser In JOpera for Eclipse you can display the value of any process parameter through a web browser in addition to the various monitoring views JOpera provides from within the Eclipse workbench 1 Starting from within a process monitor double click on the parameter you would like to display 2 This will open up the Parameter Viewer view that should already show the content of the pa rameter 50 8 4 HOW TO REPORT A BUG Parameter viewer 2 Edit Parameter Address rest_HTML Newfro ir Replace Output lt HTML gt Show Parameter In Browser lt HEAD gt lt TITLE gt My homepages TITLE gt lt HE AD gt lt BODY gt lt H1 gt My homepage lt Hl gt Welcome to my home lt BODY gt lt HTML gt Figure 8 3 Select Show Parameter In Browser 3 To display it in the browser open the view drop down menu and select Show Parameter in Browser 4 This will open a new browser window external to Eclipse that should display the parameter value Note Try to do this with a parameter that contains an HTML page 8 4 How to Report a Bug The JOpera Developers Team is of course always happy to receive bug reports Here is how to do it Use the forums found on http www jopera org to report bugs Thank you very much for
99. tion 13 12 SQL JDBC 13 13 Secure Shell Operation 13 14 Synchronous SOAP Messaging 13 15 UNIX Legacy Applications 13 16 XML transformations 13 17 Web Services Invocation Framework 98 14 How to write Documentation This chapter contains reference information about JOpera s online and offline documentation system 14 1 Setup Check out the ch ethz jopera help documentation plugin The source XML file is called jop xml the bitmap pictures in PNG format are kept in html figs and they are converted to Postscript automatically by the Ant scripts build xml file that you should use to compile the text Since this is done with some Python Imagemagik you should configure some properties of this build xml file to find them Note You do not have to close the Eclipse Help window to see your changes just refresh the embedded browser after the Ant script is done 14 2 XML Reference The list of xml tags provided for logical semantical structuring of this documentation Note Usually the description content of an element is specified as the content of the provided tag lt doc gt The root tag enclosing the entire help document lt part gt Main part of the documentation name Name Title of that part lt chap gt Chapter sectioning parts name Title of that chapter desc Optional description of that chapter lt sec gt Section for sectioning chapters name Title of that section break Optional if value is yes a page bre
100. tion plugin into JOpera A new Eclipse plugin project should be created with a dependency to the ch ethz jopera kernel and ch ethz jopera core plugins R jop xml n ch ethz jopera testsubsystem X Como Dependencies Required Plug ins Dependency Properties Specify the list of plug ins required for the operation of this plug in Define the properties of the selected dependency O Optional O Re export the dependency Version to match Match Rule a pts e tt Dependency Analysis T Look for cycles in the dependency graph Find unused dependencies x Overview Dependencies Runtime Extensions Extension Points Build plugin xml build properties Figure 12 1 Dependencies of a Subsystem plugin 39 12 HOW TO WRITE SERVICE INVOCATION PLUGINS Once the dependency are set the extensions can be declared by clicking on the corresponding tab e The first extension plugs into the JOpera kernel a new service invocation adapter class 1 Add a ch ethz jopera kernel SubSystem extension 2 Right click it and add a new SubSystem element 3 Enter the Subsystem ID SID which uniquely identifies the type of service that are going to be invoked through the SubSystem As an example in this tutorial we use TEST 4 Enter the name of the Java class which will implement the ISubsystem interface See Sec tion 12 6 on page 89 for more information on which methods of this interface shou
101. tput message To exchange data JOpera programs use input and output parameters which are edited as shown in Figure ui a Add an Input Box Parameter and call it in b Add an Output Box Parameter named out To add an adapter describing how JOpera is going to run this program click on the Add button within the Adapter Access Method section and a Choose the ECHO component type from the list in the dialog box and click Ok b Click on Edit c Then enter the following XML as input lt out gt Hallo in lt out gt Note See Section 13 6 on page 97 for more information on the syntax used by the JOpera ECHO adapter to substitute parameter values into its output string That s it Now you can go back to the Overview page to do a test run of the new HalloWorld program as we are going to show you in the rest of the tutorial 18 3 3 SETTING UP THE HALLO WORLD PROGRAM Figure 3 6 Program HalloWorld General Information O abstract C Comment Author Description Restart on Failure not restartable unlimited times restart times v Parameters Inbox Parameters 1 Name out ff in String Type String Outbox Parameters 1 Default Value Description al meu String A Access Methods Name Type Author Description Enable Overview Program Halloweorld Figure 3 5 Defining the Program interf
102. uthor 5 BPELEmpty BPELThrow 4 BPELWait ica gt lb math 7 Group By Destination INYOKE Only Divide Multiply Null Operation Power Subtract Sum Group By Parameter Count Input Output ibm 2 Group By Parameter Count Input xpath XSLT Group By Parameter Count Output L gt system reflection registry 2 Search using Regular Expression getProgramsByInterface getProgramsByName DER a L gt system signals 3 Expand All Groups Cancel Resume 8 Suspend Collapse All Groups Figure 2 9 The JOpera Library view showing the Standard JOpera Library 2 4 3 Compiling Processes Before you can run a process it needs to be compiled This is done automatically as soon as you save an OML file All you need to make sure is that in the menu Project Build Automatically is selected Alternatively you can compile the process by selecting Build A11 in the Project menu 2 GETTING STARTED Project Build Working Set Li Clean y Guild Automatically Generate Javadoc Properties Figure 2 10 Building the Processes automatically 2 4 4 Deploying Processes After they are compiled processes will be deployed automatically and transparently so that they will be immediately ready for execution Note It is possible to redeploy all processes with a Project Clean 2 4 5 Running Processes In order to run a process click on Run in the Run menu In the Run dialog select the JOpera Process launcher a
103. with the Adapter Editor Users can configure the adapter by binding the corresponding component type to a program Its input parameters are visualized to the user in the adapter editor tab and can be set to configure the information required to invoke a certain kind of service The adapter plugin does not need to implement such editor as it is automatically built by JOpera based on the component type definition The UNIX adapter input parameters are shown in Figure 12 4 You can open the notepad oml example to test the UNIX adapter Likewise the HTTP adapter input parameters are shown in Figure 12 5 You can open the doodlemashup oml example to test the HTTP adapter Note To reduce clutter since version 2 4 3 optional parameters that do not require to be configured can be grouped in the Advanced System Parameters section 12 5 3 System Parameter Types Simple Parameter Types String the default type it corresponds to a single line edit box in the adapter editor Text shown with a multi line edit box in the adapter editor URI a single line edit box The label with the name of the pa rameter can be clicked to open the URI in a Web browser Serializable parameters of this type are hidden from the adapter editor and are meant to be set using the data flow editor 88 12 6 THE ISUBSYSTEM INTERFACE Adapter Windows UNIX TER command The command to be executed Insert Variable System Parameters command notepad exe file
104. wly created OML file will show all the defined processes and programs in this OML file in the Editor Importing the WSDL file creates a new program for each of the Web Services operations Thus no processes are defined yet Adding a new process is done by clicking on the Add button right next to the Processes section Doing so will create a new process called NewProcess 4 5 Adding Input Output Parameters Double clicking or clicking on the Edit button on the newly created process will give you are more detailed view showing the process parameters tasks as well as data and control flows The first thing you may want to do is to change the name of the process to maybe get Temperature What needs to be done further is adding the input and output parameters In this simple case only one input and one output parameter is required Add these by clicking on the Add button right in the Parameters and Constants section Rename them appropriately This may be a good time to become familiar with the Problems view JOpera is periodically analyzing the processes and programs you are defining and will report problems discovered in the Problems view 24 4 6 POPULATING THE PROCESS A TemperatureService oml X Overview Programs sf NewProcess getTemp Overview Figure 4 3 Adding a new Process There are basically two problems with the process defined so far i
105. ws a setting where the data of some execution will remain valid during a one hour time span specifying a cache duration in seconds of 3600 Execution Settings Memoization Disabled Deterministic Cache for s 13600 Time Out O Figure 11 7 Caching with a one hour lifetime Used of Cached Data The last step is to use the cached data from the database during process execution This is a setting that appears in the launcher panel In the second tab Start Options the radio button Use Cached Execution Data if Available needs to be ticked This can be seen in the Figure 11 8 eno X Run Create manage and run configurations C B x a Name smallWithEcho sai x E Common J Arguments AL start E Eclipse Application 2 Equinox OSGi Fran Java Applet O Java Application Number of Process Instances to Start 11 C Delete Process Instance when it has finished C Use Cached Execution Data if Available al pe JOpera Process smallWithEcho C Suspend process instance after creation Ju JUnit Ju JUnit Plug in Test pi Recompute JOper Fr SWT Application Figure 11 8 Memoization launch configuration 11 4 Lineage Tracking 11 4 1 Introduction The goal of lineage tracking is on the one hand to perform logging of lineage data during process execution and on the other hand to allow a confortable browsing of this data accumulated in the database
106. your feedback ol 92 8 HOW TO 9 JOpera Visual Composition Language Reference This chapter still under construction contains reference information about the JOpera Visual Com position Language Some of the examples presented here can be found in the patterns oml example installed with JOpera 9 1 Basic Patterns 9 1 1 Empty Process Empty processes are supported You can use them to perform a quick mapping between their input and output parameters 9 1 2 Sequential Sequential execution of tasks is achieved by linking tasks in the control flow sequentially as depicted in Figure 9 1 Figure 9 1 Sequential task execution In the case depicted in the previous figure Taskl is executed before Task2 This control flow dependency is expressed as follows in the activator and condition properties of the tasks The activator of Task1 is left empty meaning that it will be invoked as soon as the process execution is started Task2 on the other hand has an activator which expresses the dependency on Task1 Finished Task1 Task2 will be executed only after Task1 has finished 9 1 3 Parallel Parallel execution of two or more tasks is achieved by identically setting their activators to express their dependency on the previous task or on the start of the process In the case depicted in Figure 9 2 execution of tasks Task2a and Task2b are supposed to happen in parallel after Task1 has been executed Their act

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