topic Re: Persistence in Alfresco Archive

Persistence

tizo — Mon, 24 Jan 2011 18:56:47 GMT

We have had some problems with persistence in Activiti. First I will describe the environment where we are using it.Activiti is used in an EJB, which is deployed in a GlassFish server. Spring is not used. The engine is created when an instance of the EJB is created (in a method annotated with @PostC

Re: Persistence

ronald_van_kuij — Mon, 24 Jan 2011 19:22:18 GMT

I know that probably this is a bad decision for the performance, but after finding a solution for the problem of persistence, we will try to start the Activiti engine as a GlassFish service, and obtain it with jndi.

We currently do it in an EJB3.1 singleton… works great.

- Making Activiti use the same Entity Manager that is used by the EJB, as it is configured with JTA.

This would mean rewriting the db core of Activiti… Nice, interesting excercise, but a decent amount of work.

- Making Activiti use a DataSource obtained from the container (with @Resource annotation).

Or have the option to pass in a datasource in another way. @Resource binds you to a container, which is currently not needed. Starting it in an EJB, where you have the datasource and use that when starting the engine would be an option I think.

But there is a third wat. Have Activiti use the same transaction as the container in which a call to Activiti is made. This is still experimental though, but feedback is appreciated…Look here: http://www.activiti.org/userguide/index.html#configurationRoot

Re: Persistence

jbarrez — Tue, 25 Jan 2011 09:00:35 GMT

Activiti doesnt yet (fully) work with JTA. It is on the roadmap for next month I believe (have to check).

We only have a dependency on Spring for parsing our configuration. You can use that same configurtation to configure your datasource from jndi and inject it into the Activiti configuration.

Re: Persistence

tizo — Tue, 25 Jan 2011 15:44:08 GMT

Ronald,

Thanks, thanks, thanks! I have tried the following (having obtained the datasource with the @Resource annotation before):


        ProcessEngineConfiguration pec = ProcessEngineConfiguration.createProcessEngineConfigurationFromResourceDefault();
        pec.setDataSource(datasource);
        pec.setTransactionsExternallyManaged(true);
        engine = pec.buildProcessEngine();

And it works like a charm!!

Besides, I have tried the Singleton EJB for the engine, and it works too. I have made the tests with others DB updates (with a JPA EntityManager configured with a totally independent datasource), and have proved that both updates are committed or rolled back together (probably with two-phase commit protocol). So everything is working great.

Activiti doesnt yet (fully) work with JTA.

What do you exactly mean?. All the tests that I have made worked fine. I would like to know what could fail and in what circumstances.

Thanks very much.

Re: Persistence

jbarrez — Wed, 26 Jan 2011 09:12:55 GMT

What do you exactly mean?. All the tests that I have made worked fine. I would like to know what could fail and in what circumstances.

I'm sorry, I had to be more specific. Activiti does not yet support the case when Activiti is the driver of the transactions: ie Activiti starts/commits/rollbacks the JTA transaction itself. Your case is indeed covered, as you call Activiti from within a transactional context already.

Re: Persistence

ronald_van_kuij — Wed, 26 Jan 2011 12:30:11 GMT

Would be good to add this to the docs… I'll make a jira for this