# Error migration a process

**URL:** <https://forum.flowable.org/t/error-migration-a-process/6748>\
**Category:** Flowable Engine\
**Created:** [September 21, 2020, 3:36pm UTC](https://forum.flowable.org/t/error-migration-a-process/6748 "2020-09-21T15:36:06Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![efake](https://avatars.discourse-cdn.com/v4/letter/e/e274bd/32.png) [@efake](https://forum.flowable.org/u/efake)\
**Post date:** [September 21, 2020, 3:36pm UTC](https://forum.flowable.org/t/error-migration-a-process/6748/1 "2020-09-21T15:36:06Z")

</div>

As we try to migrate the process we keep getting this error:

```
2020-09-21 15:05:22,320 [default task-1] ERROR org.flowable.common.engine.impl.interceptor.CommandContext Error while closing command context org.apache.ibatis.exceptions.PersistenceException: 
### Error updating database. Cause: com.microsoft.sqlserver.jdbc.SQLServerException: The DELETE statement conflicted with the REFERENCE constraint "ACT_FK_TIMER_JOB_PROCESS_INSTANCE". The conflict occurred in database "WF", table "i2sflow.ACT_RU_TIMER_JOB", column 'PROCESS_INSTANCE_ID_'.
### The error may exist in org/flowable/db/mapping/entity/Execution.xml
### The error may involve org.flowable.engine.impl.persistence.entity.ExecutionEntityImpl.deleteExecution-Inline
### The error occurred while setting parameters
### SQL: delete from ACT_RU_EXECUTION where ID_ = ? and REV_ = ?
### Cause: com.microsoft.sqlserver.jdbc.SQLServerException: The DELETE statement conflicted with the REFERENCE constraint "ACT_FK_TIMER_JOB_PROCESS_INSTANCE". The conflict occurred in database "WF", table "i2sflow.ACT_RU_TIMER_JOB", column 'PROCESS_INSTANCE_ID_'.
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:199)
at org.apache.ibatis.session.defaults.DefaultSqlSession.delete(DefaultSqlSession.java:212)
at org.flowable.common.engine.impl.db.DbSqlSession.flushDeleteEntities(DbSqlSession.java:569)
at org.flowable.common.engine.impl.db.DbSqlSession.flushDeletes(DbSqlSession.java:526)
at org.flowable.common.engine.impl.db.DbSqlSession.flush(DbSqlSession.java:293)
at org.flowable.common.engine.impl.interceptor.CommandContext.flushSessions(CommandContext.java:191)
at org.flowable.common.engine.impl.interceptor.CommandContext.close(CommandContext.java:61)
at org.flowable.common.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:81)
at org.flowable.common.spring.SpringTransactionInterceptor.lambda$execute$0(SpringTransactionInterceptor.java:56)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140)
at org.flowable.common.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:56)
at org.flowable.common.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:30)
at org.flowable.common.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:56)
at org.flowable.common.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:51)
at org.flowable.engine.impl.RuntimeServiceImpl.migrateProcessInstancesOfProcessDefinition(RuntimeServiceImpl.java:777)
at org.flowable.engine.impl.migration.ProcessInstanceMigrationBuilderImpl.migrateProcessInstances(ProcessInstanceMigrationBuilderImpl.java:108)
at pt.i2s.fwk.workflow.processes.beans.ProcessDefinitionMigrationService.migrateProcessInstances(ProcessDefinitionMigrationService.java:54)
at pt.i2s.fwk.workflow.services.impl.WorkflowProcessesServicesImpl.migrateProcessInstances(WorkflowProcessesServicesImpl.java:165)
... 73 more
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The DELETE statement conflicted with the REFERENCE constraint "ACT_FK_TIMER_JOB_PROCESS_INSTANCE". The conflict occurred in database "WF", table "i2sflow.ACT_RU_TIMER_JOB", column 'PROCESS_INSTANCE_ID_'.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:254)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(SQLServerStatement.java:1608)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(SQLServerPreparedStatement.java:578)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement$PrepStmtExecCmd.doExecute(SQLServerPreparedStatement.java:508)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:7240)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:2869)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(SQLServerStatement.java:243)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(SQLServerStatement.java:218)ni
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.execute(SQLServerPreparedStatement.java:493)
at org.jboss.jca.adapters.jdbc.WrappedPreparedStatement.execute(WrappedPreparedStatement.java:442)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:47)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:74)
at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:50)
at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117)
at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76)
at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:197)
... 88 more

```

At first i thought that i was doing something wrong, so i double checked everything, the processes were fine but with more investigation we found out that the query that the engine was trying to do was _“ **delete from ACT\_RU\_EXECUTION where ID\_ = ‘58b804eb-15b5-11ea-b7a8-00155dfc8176’ and REV\_ = 2** ”_ and this query is what is causing the error.  
For that process instance in question we have 2 records on the table **ACT\_RU\_EXECUTION** and the process migration fails due to a FK constraint as we can see here:

 ![image](https://canada1.discourse-cdn.com/flex035/uploads/flowable/original/2X/e/e7203e85e5e9861d99b0e02c68dd7738bd5638bd.png)

Some more information about this process, it has a timer job and after the timer a sub process is called with a single service task in it.  
Also, we are using Flowable 6.4.2.  
How can i solve this problem?

Thanks in advance.

---

<div class="post-metadata">

**Author:** ![joram](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.flowable.org/joram/32/26_2.png) [@joram](https://forum.flowable.org/u/joram)\
**Post date:** [September 22, 2020, 10:19pm UTC](https://forum.flowable.org/t/error-migration-a-process/6748/2 "2020-09-22T22:19:43Z")

</div>

Hard to say without the process model. Can you share something so we can try to reproduce the problem?

---

<div class="post-metadata">

**Author:** ![DavidPLamas](https://avatars.discourse-cdn.com/v4/letter/d/58f4c7/32.png) [@DavidPLamas](https://forum.flowable.org/u/DavidPLamas)\
**Post date:** [September 25, 2020, 5:44pm UTC](https://forum.flowable.org/t/error-migration-a-process/6748/3 "2020-09-25T17:44:35Z")

</div>

Hi @joram

I’ve found a way to isolate the problem.  
We have an event listener on the process that listens for “JOB\_CANCELED” events. This listener deletes the process instance once it’s triggered.

I’m not sure what’s happening behind the scenes when Flowable is performing the migration, but for some reason, this listener is being triggered and I think that’s why you get this error. I’ve tried migrating the exact same process without the listener and the error does not occur.  
It looks to me like this listener shouldn’t be triggered at that time.

```xml
<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:flowable="http://flowable.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="ModuleMacroProcess">
  <process id="bpmnMigration" name="Bpmn Migration" isExecutable="true" flowable:candidateStarterGroups="flowableUser">
    <extensionElements>
      <flowable:eventListener events="JOB_CANCELED" class="com.flowable.bpmn.migration.CancelProcess" onTransaction="committed"></flowable:eventListener>
    </extensionElements>
    <startEvent id="startnoneevent1" flowable:initiator="initiator" flowable:formFieldValidation="false"></startEvent>
    <intermediateCatchEvent id="theTimer" name="Timer">
      <timerEventDefinition>
        <timeDuration>${timerduration}</timeDuration>
      </timerEventDefinition>
    </intermediateCatchEvent>
    <sequenceFlow id="sequenceFlow2" sourceRef="startnoneevent1" targetRef="theTimer">
    </sequenceFlow>
    <endEvent id="endNoneEvent1">
    </endEvent>
    <sequenceFlow id="sequenceFlow3" sourceRef="theTimer" targetRef="scriptTask1">
    </sequenceFlow>
    <scriptTask id="scriptTask1" name="Script task" scriptFormat="groovy" flowable:autoStoreVariables="false">
      <script><![CDATA[sum = 0
      test = 2
    for ( i in inputArray ) {
      sum += i
    }]]></script>
    </scriptTask>
    <sequenceFlow id="sequenceFlow4" sourceRef="scriptTask1" targetRef="endNoneEvent1">
    </sequenceFlow>
  </process>
</definitions>

```

```java
package com.flowable.bpmn.migration;

import org.flowable.common.engine.api.delegate.event.FlowableEngineEventType;
import org.flowable.common.engine.api.delegate.event.FlowableEntityEvent;
import org.flowable.common.engine.api.delegate.event.FlowableEvent;
import org.flowable.common.engine.api.delegate.event.FlowableEventListener;
import org.flowable.engine.ProcessEngines;
import org.flowable.job.service.impl.persistence.entity.TimerJobEntity;

public class CancelProcess implements FlowableEventListener {
    @Override
    public void onEvent(FlowableEvent event) {

        if (event.getType().equals(FlowableEngineEventType.JOB_CANCELED)) {
            FlowableEntityEvent flowableEntityEvent = (FlowableEntityEvent) event;
            TimerJobEntity timerJobEntity = (TimerJobEntity) flowableEntityEvent.getEntity();
            ProcessEngines.getDefaultProcessEngine().getRuntimeService().deleteProcessInstance(timerJobEntity.getProcessInstanceId(), "TEST");
        }
    }

    @Override
    public boolean isFailOnException() {
        return true;
    }

    @Override
    public boolean isFireOnTransactionLifecycleEvent() {
        return false;
    }

    @Override
    public String getOnTransaction() {
        return null;
    }
}

```

Is there anything that can be done to prevent this from happening?  
I have considered disabling the eventDispatcher while this migration is happening but I’m afraid that might have negative side effects…

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<div class="post-metadata">

**Author:** ![joram](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.flowable.org/joram/32/26_2.png) [@joram](https://forum.flowable.org/u/joram)\
**Post date:** [September 30, 2020, 10:16pm UTC](https://forum.flowable.org/t/error-migration-a-process/6748/4 "2020-09-30T22:16:35Z")

</div>

Thanks @DavidPLamas, that’s very useful. Will try to reproduce it with that.

> [@DavidPLamas](#):
>
> I have considered disabling the eventDispatcher while this migration is happening but I’m afraid that might have negative side effects…

That’s an option indeed. If nothing else is running at that moment, the event dispatched can be disabled. However, I assume other instances will still need it while this one is being migrated?

---

<div class="post-metadata">

**Author:** ![DavidPLamas](https://avatars.discourse-cdn.com/v4/letter/d/58f4c7/32.png) [@DavidPLamas](https://forum.flowable.org/u/DavidPLamas)\
**Post date:** [October 1, 2020, 10:23am UTC](https://forum.flowable.org/t/error-migration-a-process/6748/5 "2020-10-01T10:23:50Z")

</div>

> [@joram](#):
>
> That’s an option indeed. If nothing else is running at that moment, the event dispatched can be disabled. However, I assume other instances will still need it while this one is being migrated?

Yes, you’re right.  
I was thinking about creating a jar/war application just to migrate this process. It would set up the engine using the same configuration but disabling the event dispatcher.  
Do you think this is viable?