topic Trying to understand how service tasks and listeners work in Alfresco Archive https://connect.hyland.com/t5/alfresco-archive/trying-to-understand-how-service-tasks-and-listeners-work/m-p/204774#M157904 <HTML><HEAD></HEAD><BODY><SPAN>We are having a problem and we'd like to understand a bit how Activiti's Engine works. Let assume the following flow example:</SPAN><BR /><BR /><SPAN>start -&gt; ServiceTask1 -&gt; ServiceTask2 -&gt; end</SPAN><BR /><BR /><UL><LI>Both ServiceTasks are async</LI><LI>Both ServiceTasks has a Listener when each of them starts.</LI><LI>Both Listeners update a row in one of our business tables.</LI></UL><HR /><BR /><SPAN>The problem is that we are having Optimistic Lock errors because it seems that both listeners are trying to update the same row at the same time.</SPAN><BR /><BR /><SPAN>We guess that what is happening is:</SPAN><BR /><UL><LI>The ServiceTask doesn't wait for the start Listener to finish</LI><LI>So ServiceTask1 finishes before its start Listener finishes and the start Listener of ServiceTask2 reads the db row before the Listener of ServiceTask1 writes the update</LI><LI>ServiceTask1's Listener writes the update</LI><LI>When ServiceTask2's Listener wants to write the update, the version is different so it throws an optimistic lock.</LI></UL><HR /><BR /><SPAN>So, the questions we need to answer are:</SPAN><BR /><BR /><UL><LI>Is this how ServiceTask's Listeners works or are we missing something?</LI><LI>Is there any way to make ServiceTasks to wait for the start Listener?</LI></UL><SPAN>Thanks in advance!</SPAN><BR /></BODY></HTML> Thu, 16 Apr 2015 14:12:49 GMT neuquino 2015-04-16T14:12:49Z Trying to understand how service tasks and listeners work https://connect.hyland.com/t5/alfresco-archive/trying-to-understand-how-service-tasks-and-listeners-work/m-p/204774#M157904 We are having a problem and we'd like to understand a bit how Activiti's Engine works. Let assume the following flow example:start -&gt; ServiceTask1 -&gt; ServiceTask2 -&gt; endBoth ServiceTasks are asyncBoth ServiceTasks has a Listener when each of them starts.Both Listeners update a row in one of Thu, 16 Apr 2015 14:12:49 GMT https://connect.hyland.com/t5/alfresco-archive/trying-to-understand-how-service-tasks-and-listeners-work/m-p/204774#M157904 neuquino 2015-04-16T14:12:49Z Re: Trying to understand how service tasks and listeners work https://connect.hyland.com/t5/alfresco-archive/trying-to-understand-how-service-tasks-and-listeners-work/m-p/204775#M157905 <HTML><HEAD></HEAD><BODY><SPAN>Hi,</SPAN><BR /><BR /><BLOCKQUOTE class="jive-quote">Is this how ServiceTask's Listeners works or are we missing something?</BLOCKQUOTE><SPAN>No, It should not work in this way. ServiceTask1 transaction is committed after the ServiceTask2&nbsp; job is created. But I do not know what you missed. </SPAN><BR /><SPAN>(can you create jUnit test? </SPAN><A href="http://forums.activiti.org/content/sticky-how-write-unit-test" rel="nofollow noopener noreferrer">http://forums.activiti.org/content/sticky-how-write-unit-test</A><SPAN>)</SPAN><BR /><BR /><SPAN>Regards</SPAN><BR /><SPAN>Martin</SPAN></BODY></HTML> Fri, 17 Apr 2015 06:47:03 GMT https://connect.hyland.com/t5/alfresco-archive/trying-to-understand-how-service-tasks-and-listeners-work/m-p/204775#M157905 martin_grofcik 2015-04-17T06:47:03Z