topic Re: Hung Process using Intermediate Start Timer in Alfresco Archive

Hung Process using Intermediate Start Timer

dan1 — Mon, 29 Oct 2012 22:56:46 GMT

Hi,I'm having issues using Intermediate Start Timer. The issue is somewhat intermittent. Sometimes the timer fires ok and invokes the delegate. Sometimes I get an ActivitiOptimisticLockingException but the timer still works. This goes on for a bit (timer works no exception intermixed with exceptions

Re: Hung Process using Intermediate Start Timer

jbarrez — Tue, 30 Oct 2012 06:32:03 GMT

Wow … this is really, really weird.

First of all: do you have multiple job executors running? If you get optimistic locking exceptions, it is normally the case some other thread is trying to fire the timer.

But for the redeployment … wow I've got no clue why that happens… it might be that the process is evicted from the internal cache, but then it should find the class to instantiate. Is is possible to put that in a unit test, even if it only fails sometimes?

Re: Hung Process using Intermediate Start Timer

frederikherema1 — Tue, 30 Oct 2012 06:34:41 GMT

Do you have 2 activiti-engines running at the same time? How do you deploy the process in the first place?

Re: Hung Process using Intermediate Start Timer

dan1 — Tue, 30 Oct 2012 09:55:53 GMT

I'm effectively running the demo as is with the addition of 2 processes I created. I manually copy the jar files into activiti-explorer/WEB-INF/lib and restart tomcat. Then use activiti-explorer to upload the bar file and run the process.

My assumption is that the demo runs a single engine? Both activiti-explorer and activiti-rest are deployed in tomcat. The activiti-explorer project runs a Job Executor but I don't see anything similar for activiti-rest.

In activiti-explorer config files:


applicationContext.xml:         <property name="jobExecutorActivate" value="true" />

Note that I have the demo installed in 2 different environments. One uses demo.start as is after downloading 5.10. In the other case, I modified some things to run this in a mocked up version of my deployment environment. That one runs on tomcat 7.0.2. I originally saw this in my mocked up deployment environment and thought it was something I screwed up while merging the config files. But then I easily reproduce this in the original demo environment.

I can create a unit test but it might not be today. I have to focus on some other things.

Thanks,
Dan

Re: Hung Process using Intermediate Start Timer

dan1 — Tue, 30 Oct 2012 12:24:21 GMT

I have an update on this issue.

I wanted to check out the Activiti Modeler. So in my demo environment, I replaced the activiti-explorer with the new one on the download page. And now this problem seems to have gone away. My timer has fired hundreds of times without issue. I don't get any of the tracebacks.

The jar files look the same (with the exception of the additional jars used by the modeler)?

Dan

Re: Hung Process using Intermediate Start Timer

jbarrez — Wed, 31 Oct 2012 07:03:16 GMT

Yeah, the jars should be the same …

But you said you have two environments … if they both run the job executor and go to the same database, than the messages you see are normal.
Do note that the beta modeler runs on an in-memory H2 database, while Explorer goes to one through tcp (which is mapped to the filesystem). Maybe thaty is the reason you don't see any collisions now?