1. jBPM4 container
integration: Deployer
Heiko Braun <hbraun@redhat.com>
09.03.2009

2. Overview
• Process deployment specifics
• Concepts and gotchas with deployment/
undeployment
• Status and next steps

3. AS deployments
• Create a *.par archive and copy it to
server/<config>/deploy
• Can be done while AS running or when it’s
shutdown
• Covered by the AS deployer API

4. Process deployment:
BPM specifics
• In BPM we expect long running processes
• i.e. exists across AS reboots
• Processes are versioned:
• Deployment can lead to a new version
or “replace” a prior one (aka patching)
• Process model is actually a database model:
• Redeployment is not idempotent [1]
[1] “Acting as if used only once, even if used multiple times. “

5. Deployment
• Two approaches: Version or
timestamp identification
• Version: Explicit as part of
the process definition
(*.jpdl.xml)
• Timestamp: Implicit, refers
to the actual deployment
artifact (filesystem)
• Applies to the same deployment
artifact (filename)
• Derived policy identifies
processes that will be stored in
DB

6. Deployment scenarios
• Patching a process (i.e. replacing a class,
bugfix, etc):
- same artifact with same version
• Providing a new process (i.e. different pdl):
- same artifact different version, or no
version at all
• Otherwise: New artifact, new version

7. Undeployment
• Single approach: Does the
deployment artifact exist?
• Usally undeployment happens
when removing files from server/
<config>/deploy
• Exception: On server shutdown,
all deployer get undeployment
callbacks
• Only if the deployment artifact
is deleted the process will be
removed

8. Undeployment
scenarios
• Server shutdown
- retain process
• Artifact removed w. server running
- delete process
• Artifact removed with server stopped
- Not realized by process engine ?!

9. Process lifecycle and
classloader
• Server boot
- Associate classloader, flag process “ready”
• Server shutdown
- Remove classloader, flag process “shutdown”
• Gotcha: Artifact removed while server is shutdown
• upon boot only processes w. artifacts will be flagged
“ready”
• leaves non-usable (“shutdown”) processes that need to
be removed manually

10. Status
• Resides in ‘modules/integration’
• Implemented for AS 5
• No JNDI binding yet
• No classloader association
• Works as proof of concept

11. Next steps
• Port to AS 4.2.x
• Implement JNDI bindings
• Relationship to ‘enterprise’ module
• Extended in container test coverage

12. Q&A

13. Appendix:
Implemention on AS 5
• Deployment example
16:22:41,522 INFO [JBPMDeployer] Deploy JBPMDeploymentMetaData {unit=vfszip:/Users/hbraun/dev/prj/jboss/tags/JBoss_5_0_0_GA/build/
output/jboss-5.0.0.GA/server/default/deploy/Simple-Alpha2.jar/Simple_noversion.jpdl.xml, jpdl=vfszip:/Users/hbraun/dev/prj/jboss/tags/
JBoss_5_0_0_GA/build/output/jboss-5.0.0.GA/server/default/deploy/Simple-Alpha2.jar/Simple_noversion.jpdl.xml,
cl=BaseClassLoader@bc4d42{vfszip:/Users/hbraun/dev/prj/jboss/tags/JBoss_5_0_0_GA/build/output/jboss-5.0.0.GA/server/default/deploy/Simple-
Alpha2.jar}}
16:22:41,571 INFO [VersionTimestampPolicy] Timestamp driven policy evaluation: process 'Simple_noversion', timestamp 1236612157000
16:22:41,615 INFO [JBPMDeployer] Deploy JBPMDeploymentMetaData {unit=vfszip:/Users/hbraun/dev/prj/jboss/tags/JBoss_5_0_0_GA/build/
output/jboss-5.0.0.GA/server/default/deploy/Simple-Alpha2.jar/Simple_version.jpdl.xml, jpdl=vfszip:/Users/hbraun/dev/prj/jboss/tags/
JBoss_5_0_0_GA/build/output/jboss-5.0.0.GA/server/default/deploy/Simple-Alpha2.jar/Simple_version.jpdl.xml,
cl=BaseClassLoader@bc4d42{vfszip:/Users/hbraun/dev/prj/jboss/tags/JBoss_5_0_0_GA/build/output/jboss-5.0.0.GA/server/default/deploy/Simple-
Alpha2.jar}}
16:22:41,641 INFO [VersionTimestampPolicy] Version driven policy evaluation: process 'Simple_withversion', version 3

14. Appendix:
Implemention on AS 5
• Embracing EE5:
2009-03-09 15:26:22,737 INFO [org.jbpm.integration.jboss5.JBPMServiceImpl] (main) ProcessEngine bound to: java:/jbpm4
class myEJB {
[...]
try
{
InitialContext ctx = new InitialContext();
this.processEngine = (ProcessEngine)ctx.lookup(quot;java:/jbpm4quot;);
}
catch (Exception e)
{
throw new RuntimeException(quot;Failed to lookup process enginequot;);
}
}