topic Re: How to have only one instance of a service Task running in Alfresco Archive

How to have only one instance of a service Task running

mimani — Mon, 20 Oct 2014 06:11:57 GMT

HI,I am developing a workflow using activiti-5.15.1, where I am picking some data from a system and doing processing on it. I am using a Service Task in the beginning of the flow to fetch data from the other system. Now, there is possibility, that if multiple processes of this workflow runs in paral

Re: How to have only one instance of a service Task running

jbarrez — Mon, 20 Oct 2014 09:31:53 GMT

This looks to me like the data needs to be fetched from a typical queue (eg JMS) to guarantee that only one consumer can take the data

Re: How to have only one instance of a service Task running

mimani — Fri, 24 Oct 2014 17:44:27 GMT

This is not just about reading serially but I want to block the read until This service task completes and I mark the data as processed.

So I was thinking, I will fetch the data and after processing, mark the data in the service task as processed so if only one service task executes at a time, It will never fetch same data in different processes. I am not sure what should be correct approach for this case.

Re: How to have only one instance of a service Task running

jbarrez — Mon, 27 Oct 2014 11:14:48 GMT

I'm not sure if I'm fully following what you are trying to do here … but as far as I read it, you should be able to do this with a typical queue implementation. You need one producer that puts the data on the queue, and then the queue guarantees only one will process it.