1. ODE Instance Migration
Hanna Eberle, Tammo van Lessen, Tobias Unger
University of Stuttgart
Institute of Architecture of Application Systems (IAAS)
© IAAS 1

2. Outline
1 Introduction
2 BPEL Related Stuff
3 ODE Related Stuff
© IAAS 2

3. Motivation
 Migration
 Update to an new ODE version
 In mobile computing people takes their instances with them
across devices and infrastructures
 Modification
 Adding additional steps to an already running instance
 Adapting running instances to a new version of the process
model
 Distribution
 Dynamic outsourcing of parts of already running instances
 Function vs. Data shipping
 In distribution and modification scenarios instance
modification implies modification of process model
© IAAS 3

4. Approach
 Problem
 Each scenario requires sophisticated modifications of the ODE
engine
 Overlapping functionallity
 Solutions
 Generic instance format based on XML
 ODE interface for importing and exporting instances
 Components controlling modification, distribution, or
migration can be realized separated from the ODE engine
 ODE engine has to be modified only once
© IAAS 4

5. Vision
Distribution Apache ODE
BPEL
OModel
Compiler
Process Instance BPEL Runtime
Axis2
Management &
JACOB DAOs
JBI
Events
SCA
Migration to other Server
Hiber Open
Scheduler
… nate JPA
DB
Apache ODE
Process Instance
BPEL Apache ODE
OModel
Compiler BPEL
OModel
Compiler
Process Instance
BPEL Runtime BPEL Runtime
Axis2 Axis2
Management &
Management &
JACOB DAOs
JACOB DAOs
JBI
Events
JBI
Events
SCA
Hiber Open
SCA Scheduler
Hiber Open … nate JPA
Scheduler
… nate JPA
DB
DB
Process Instance Process Instance
Apache ODE
BPEL
Compiler
OModel
Modification
BPEL Runtime
Axis2
Management &
JACOB DAOs
JBI
Events
SCA
Hiber Open
Scheduler
… nate JPA
DB
© IAAS 5

6. Metamodel View
 Defining a XML-schema based metamodel for process
instances
Activity Link Defined using XML-
Process (Modeling) Language (BPEL) Schema
Described by
A3 e.g. Medication Modeled using XML-
A1 A4
Process Model A2 Flow File
Currently, instance is stored
A3
Described by A1 A4 e.g. Patient = Bill in an engine dependent
A2 format (e.g. Java objects
Process Instance
and/or database)
What we want
to add… Process
Instance
XML-File containing a process
instance based on a well defined
XML-File format (XML-Schema)
© IAAS 6

7. Outline
1 Introduction
2 BPEL Related Stuff
3 ODE Related Stuff
© IAAS 7

8. Example
Process Model Process Instance Process Instance XML
id=1
<bpelinstance id=quot;2quot;>
Sequence Sequence <state>running</state>
id=2 …
Empty Empty </bpelinstance>
id=3
While While
id=4
Flow Flow
id=5
Invoke1 Invoke1
true
id=6
Invoke2 Invoke2
id=7
Flow
id=8
Invoke1
© IAAS 8

9. Import and Export
Export Import
Trigger
Suspending Export Import Resume
Instance
Activities Instance Instance Instance
Suspension
 Idea: Import and export of suspended process instances
 Problems
 Suspending to a save state
 Suspension of Wait, Pick (Receive)
 Running request-response invocations
 Maybe activity cannot be suspended
 Event Handler, FCT-Handling
 Which activities can be suspended? Which must be continued
until completed state?
© IAAS 9

10. Instance Format – Possible Content
 Important content
 Activity instances (state, IDs, etc.)
 Variable data
 Message exchanges
 Depends on Binding (JMS vs. HTTP)
 Correlation sets
 Link states
 Snapshots
 History
 Process Model must be integrated optionally
 Not sure whether process model is present at target engine
© IAAS 10

11. Models to be defined
 State model for BPEL
 Model for representing instances
© IAAS 11

12. Outline
1 Introduction
2 BPEL Related Stuff
3 ODE Related Stuff
© IAAS 12

13. ODE Implications
 Compiler
 Implicit scopes (E.g. invoke)
 Deployment
 Deployment descriptor
 State mapping
 Activity and process states
 ODE Extensions
 REST
 External variables
 …
© IAAS 13

14. Where to Collect Information about/within ODE
 Process Management API
 Using test process (long running wait activity)
 Code Review
 Process (Instance) States
 Debugging
 Using Management API and test process
© IAAS 14

15. ODE Process (Instance) States
 Process States
 org.apache.ode.bpel.iapi.ProcessState
 ACTIVE
 RETIERED
 DISABLED
 Process Instance States
 org.apache.ode.bpel.common.ProcessState
 STATE_NEW = 0
 STATE_READY = 10
 STATE_ACTIVE = 20
 STATE_COMPLETED_OK = 30
 STATE_COMPLETED_WITH_FAULT = 40
 STATE_SUSPENDED = 50
 STATE_TERMINATED = 60
© IAAS 15

16. ODE Activity Instance States
 org.apache.ode.bpel.pmapi.TActivityStatus
 static final Enum ENABLED = Enum.forString(quot;ENABLEDquot;);
 static final Enum STARTED = Enum.forString(quot;STARTEDquot;);
 static final Enum COMPLETED = Enum.forString(quot;COMPLETEDquot;);
 static final Enum FAILURE = Enum.forString(quot;FAILUREquot;);
 static final Enum DEAD = Enum.forString(quot;DEADquot;);
© IAAS 16

17. ODE Scope Instance States
 org.apache.ode.bpel.dao.ScopeStateEnum
 ACTIVE
 FAULTED
 FAULTHANDLER
 COMPLETED
 COMPENSATING
 COMPENSATED
© IAAS 17

18. Management API – Activity Info
 getScopeInfoWithActivity
<ns:activity-info>
<ns:name>receiveInput</ns:name>
<ns:type>OPickReceive</ns:type>
<ns:aiid>3</ns:aiid>
<ns:status>COMPLETED</ns:status>
<ns:scope modelId=quot;0quot; name=quot;__PROCESS_SCOPE:Waitquot; siid=quot;201quot;/>
<ns:dt-enabled>2009-04-08T13:34:01.760+02:00</ns:dt-enabled>
<ns:dt-started>2009-04-08T13:34:01.760+02:00</ns:dt-started>
<ns:dt-completed>2009-04-08T13:34:01.892+02:00</ns:dt-completed>
</ns:activity-info>
© IAAS 18

19. Management API – Instance Info
 getInstanceInfo
<instance-info>
<ns:iid xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;>151</ns:iid>
<ns:pid xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;>{http://iaas.de}Wait-
4</ns:pid>
<ns:process-name xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;
xmlns:iaas=quot;http://iaas.dequot;>iaas:Wait</ns:process-name>
<ns:root-scope siid=quot;201quot; status=quot;ACTIVEquot; name=quot;__PROCESS_SCOPE:Waitquot; modelId=quot;3quot;
xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;/>
<ns:status xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;>FAILED</ns:status>
<ns:dt-started xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;>2009-04-
08T13:34:01.000+02:00</ns:dt-started>
<ns:dt-last-active xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;>2009-04-
08T13:44:02.000+02:00</ns:dt-last-active>
<ns:event-info xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;/>
<ns:fault-info xmlns:ns=quot;http://www.apache.org/ode/pmapi/types/2006/08/02/quot;>
<ns:name xmlns:exec=quot;http://docs.oasis-
open.org/wsbpel/2.0/process/executablequot;>exec:uninitializedVariable</ns:name>
<ns:explanation xsi:nil=quot;truequot; xmlns:xsi=quot;http://www.w3.org/2001/XMLSchema-instancequot;/>
<ns:line-number>65</ns:line-number>
<ns:aiid>20</ns:aiid>
</ns:fault-info>
</instance-info>
© IAAS 19

20. Literature
 Karastoyanova, Dimka; Khalaf, Rania; Schroth, Ralf;
Paluszek, Michael; Leymann, Frank: BPEL Event
Model, Technical Report No. 2006/10 (will be updated
soon)
© IAAS 20

21. End of Document