Instances hang with concurrency

malizor

Hi,

I attached a simple .BPMN with which I managed to reliably reproduce my issue.

It only contains script tasks, though I originally noticed this behavior with Java service tasks.

There are 5 script tasks witch are all marked as async.
The first 4 do nothing and the fifth one sleeps for 2 minutes (in my experience, it works the same with any other service task that is "long to process").

What I observe when launching new instances is the following:

• The first and second instances go through the workflow and wait on the wait_script
• The third one stay on script1 for some seconds then goes to wait_script
• The fourth one stay on script1 until the first two instances finish.

I also tried launching 100 instances of this same workflow at once.
In this case I observed that they are all processed very slowly. It seems the instances advanced by batches of around 20, in no particular order, and that they stayed on wait_script for more than 2 minutes.
All in all, the 100 instances needed about 20 minutes to complete.

Note that I tried to modifie the asyncExecutor settings but I did not notice any change.

I set the following settings:

<property name="jobExecutorActivate" value="false" />
<property name="asyncExecutorEnabled" value="true" />
<property name="asyncExecutorActivate" value="true" />‍‍‍

and:

<bean id="asyncExecutor" class="org.activiti.engine.impl.asyncexecutor.DefaultAsyncJobExecutor">
    <property name="corePoolSize" value="100" />
    <property name="maxPoolSize" value="2000" />
    <property name="keepAliveTime" value="3000000" />
    <property name="queueSize" value="20000" />
    <property name="maxTimerJobsPerAcquisition" value="2000" />
    <property name="maxAsyncJobsDuePerAcquisition" value="2000" />
    <property name="defaultAsyncJobAcquireWaitTimeInMillis" value="10000" />
    <property name="defaultTimerJobAcquireWaitTimeInMillis" value="10000" />
    <property name="timerLockTimeInMillis" value="60000" />
    <property name="asyncJobLockTimeInMillis" value="60000" />
</bean> ‍‍‍‍‍‍‍‍‍‍‍‍                                                                                        

I don't understand why instances seems to get stuck when other are being processed.

Why all my instances do not go directly at the wait_script step? Why can't they all process concurrently?


Note that it works fine if I unset all async flags, so it seems to me that this is related to the job executor.

What I concluded is that Activiti expects a job execution to be relatively short, but it's not a really satisfying answer.

I'm using Activiti 5.22 , deployed in Tomcat7 (process deployed in the explorer and launched via the REST API).

test3.bpmn.zip

unknown

If you want to increase the number of jobs to be executed concurrently, you should change asyncExecutorCorePoolSize and asyncExecutorMaxPoolSize.
https://github.com/Activiti/Activiti/blob/master/modules/activiti-engine/src/main/java/org/activiti/engine/impl/asyncexecutor/DefaultAsyncJobExecutor.java

The setting of asyncExecutorCorePoolSize is the thread pool size to execute async job.
Because asyncExecutorCorePoolSize' initial value is 2 and your process sleep, the two process's scripts of your five process occupy the thread pool.