topic Re: Error in async process- Error while closing command context in Alfresco Archive

Error in async process- Error while closing command context

k_kunti — Sat, 01 Dec 2012 07:23:28 GMT

Dear Activiti team I am using activiti 5.10 with SQLserver DB. My process has 4 async service task where each task call a stored procedure that takes 1 min to execute. I am getting the following exception when I start 100 instances using Jmeter. I have attached my process definition and engine confi

Re: Error in async process- Error while closing command context

k_kunti — Sun, 02 Dec 2012 04:30:30 GMT

Dear Activiti Team

It would be a big help if you can point me to the packeges where core job executor logic is implemented and how async tasks uses the same.

Thank you
Best Regards
Krishnendu

Re: Error in async process- Error while closing command context

ronald_van_kuij — Sun, 02 Dec 2012 09:35:00 GMT

It's in the JobExecutor class…

Re: Error in async process- Error while closing command context

ronald_van_kuij — Sun, 02 Dec 2012 09:36:22 GMT

And next time, please use code tags around yor code… Reads much easier…

Re: Error in async process- Error while closing command context

k_kunti — Mon, 10 Dec 2012 10:41:36 GMT

Hi All

Looks like this issue is coming up in SQL server DB when there are many concurrent process trying to update access the same table at the same time. In my case there were 200 concurrent process which where completing almost the same time.

Looks like when there are too many updates in SQL server DB row locks are converted to table level locks resulting in this behavior. One solution is using some connection pooling solution which allows default isolation level as snapshot isolation level in SQL server. Unfortunately I could not find any open source connection pooling API using which I could achieve the same.

Thank you
Krishnendu

Re: Error in async process- Error while closing command context

jbarrez — Tue, 11 Dec 2012 07:08:39 GMT

Looks like when there are too many updates in SQL server DB row locks are converted to table level locks resulting in this behavior.

Are you sure about, that sounds very, very strange for a database to do. Then again, it is of course a database from MS 😉
But if that is really the problem, then you need indeed some kind of throttling mechanism to avoid hitting the database to hard. Or I would there is a setting you can change in the configuration of the db.

Re: Error in async process- Error while closing command context

ronald_van_kuij — Tue, 11 Dec 2012 08:03:24 GMT

Well, wikipedia even has some info on this: http://en.wikipedia.org/wiki/Lock_(database) and ofcourse the MS site: http://msdn.microsoft.com/en-us/library/ms184286(v=sql.105).aspx