topic multiInstanceLoopCharacteristics not executed concurrently in Alfresco Archive

multiInstanceLoopCharacteristics not executed concurrently

akirafei — Mon, 05 Jan 2015 21:07:45 GMT

Hi,I created a service task with multiInstanceLoopCharacteristics. It is working fine but I found that task instances are executed sequentially not concurrently although I set isSequential="false" .The task configuration is<serviceTask id="XXX" name="XXX" activiti:delegateExpression="${xxx}" acti

Re: multiInstanceLoopCharacteristics not executed concurrently

akirafei — Mon, 05 Jan 2015 21:13:33 GMT

The task configuration is
<serviceTask id="XXXTask" name="XXXTask" activiti:delegateExpression="${XXXTask}" activiti:exclusive="false">
<multiInstanceLoopCharacteristics isSequential="false" activiti:collection="xxxRequestList" activiti:elementVariable="xxxRequest"></multiInstanceLoopCharacteristics>
</serviceTask>

The engine configuration:
<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration"
depends-on="dataSource,transactionManager">
<property name="databaseType" value="h2" />
<property name="dataSource" ref="dataSource" />
<property name="transactionManager" ref="transactionManager" />
<property name="databaseSchemaUpdate" value="create-drop" />
<property name="jobExecutorActivate" value="false" />
<property name="history" value="full" />
<property name="deploymentResources" value="classpath*:activiti/*.bpmn" />
</bean>

<bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean"
depends-on="processEngineConfiguration">
<property name="processEngineConfiguration" ref="processEngineConfiguration" />
</bean>

Re: multiInstanceLoopCharacteristics not executed concurrently

ollib — Tue, 06 Jan 2015 06:44:44 GMT

Tasks are always executed in some sequential order. Tasks in an multi instance construct are no exeception to this rule. Think of 10 user tasks that are started as multi instance tasks. Each task is started (one after the other) and then blocks, because it needs a user decision. So you have 10 active tasks. Now think of 10 user tasks that are executed sequentially. In this case you would only have 1 active user task at a time.

Re: multiInstanceLoopCharacteristics not executed concurrently

akirafei — Tue, 06 Jan 2015 19:08:08 GMT

Thanks ollib for the reply. Then what does the property is_Sequential mean?

My goal is to have parallel executed multi instance pattern since they do not have dependencies and performance is critical to me. Is there any solution in activiti?

Thanks.

Re: multiInstanceLoopCharacteristics not executed concurrently

ollib — Wed, 07 Jan 2015 06:03:42 GMT

I don't think that a workflow system is the best choice if you are really after realtime concurrency. Parallel vs sequential is more a concept. Two tasks a and b are sequential if b cannot be started until a has ended. Two tasks a and b are parallel if they can be started independently from each other. This doesn't mean that they start exactly at the same time technically.