[jboss-jira] [JBoss JIRA] Created: (JBRULES-3108) problems with concurrent process executions, constraints, and multiple sessions

[Jordi Alvarez (JIRA)]

problems with concurrent process executions, constraints, and multiple sessions
-------------------------------------------------------------------------------

                 Key: JBRULES-3108
                 URL: https://issues.jboss.org/browse/JBRULES-3108
             Project: Drools
          Issue Type: Bug
      Security Level: Public (Everyone can see)
          Components: drools-core (flow)
    Affects Versions: 5.2.0.Final, 5.1.1.FINAL
         Environment: Independent of OS, JVM, and Application Server. Reproduced in a windows development environment with a Sun JVM. Also reproduced in linux. Also database independent: reproduced with Oracle RDBMS and HSQLDB.
            Reporter: Jordi Alvarez
            Assignee: Mark Proctor


The context is as follows:
1. We have drools flow configured with JPA and Hibernate, accessing an Oracle / HSQLDB database (depending on the environment).
2. We do have several concurrent stateful sessions in which different instances of the same kind of processes are running. These stateful sessions are persisted in the same database schema.
3. We do use wait states (also reproduced with rule nodes) that have constraints that wait for a fact to be inserted into the stateful session.
4. Whenever the fact that makes the constraint to satisfy is inserted for one process in a given stateful session; if there are other processes waiting in that wait state/constraint (in other different stateful sessions), the stateful session tries also to continue those process executions, even when they are not part of it.

A solution has been implemented temporally over drools source code (in order to get our context working): the solution is briefly described in the forum url below. For completeness a summary is included here:
- Adding a new attribute to org.drools.persistence.processinstance.ProcessInstanceInfo POJO identifying the stateful session to which the process instance corresponds (and the corresponding DB column).
- modifying the ProcessInstancesWaitingForEvent query (in orm.xml) in order to take into account the session id as a (new) second parameter.
- modify the class org.drools.persistence.processinstance.JPASignalManager in order to execute the query with both parameters.
- as a quick way to have the session id, we have a threadlocal.


--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira