Multiple process engines - one database

[Stefan Schulz]

Hello.

Is it possible/a good idea to let more that one process engine talk to one database (i think i heard bernd say that this is not the case somewhere on youtube, but i can not find the video anymore)? The IT architecture of my company mainly consists of two debian servers having one jboss each (talking to the same db, running in parallel if needed). If the relation between process engine and (process) db could be different from 1:1, then we could just boot one process engine for each of our debians and the let the delegate code of our processes talk to the 'localhost' jboss. If we would have to guarantee a 1:1 relation, the alternative i see is to just boot a process engine on one of the debians and implement a mechanism which can switch between the jbosses (debian1:1099 <-> debian2:1099) the delegate code is talking to.

As the first possibility would be far more simple to implement, it would be nice if anyone could give a comment about this.

Thanks,

Stefan

[webcyberrob]

Hi Stefan,

Have a look in the Clustered Deployment section of the user guide;

"...In order to provide scale-up or fail-over capabilities, the process engine can be distributed to different nodes in a cluster. Each process engine instance must then connect to a shared database...."

One 'feature' of this architecture Im aware of is there are occasional warnings as the jobexcutors optimistic locking mechanisms 'trip over' each other...

Rob

[Christian Lipphardt]

Hi Stefan,

Like Rob already wrote, you can install the bpm platform on each of your nodes and point them to the same database. Then just deploy your process applications to each node, creating a homogeneous cluster.

See our documentation for clustering.

Cheers
Christian

[Christian Lipphardt]

Link to our clustering documentation: http://docs.camunda.org/latest/guides/user-guide/#process-engine-the-job-executor-cluster-setups