event.processing.enabled setting

[jonnyg]

From an unresolved support request*

We were getting an ORA-00933 error within com.activiti.service.runtime.ActivitiEventProcessingService.findFirstLockableEventLogNr() some time back. We worked around it by setting <em>event.processing.enabled=false</em>.

In the default activiti-app.properties, this is first set to true, and <i>then later</i> to false in the section "# EVENT PROCESSING TWEAKING"
Here's the help comments:

# Set to false to not to event processing. This could be useful 
# in a clustered setup where only sone nodes do the processing
‍‍‍‍

This is vague to a fault. Do you mean to say that this should be set to true <i>on at least one server</i>?
What would happen if no server set it to true?


* it's #00663870. It was closed because I didn't have time to respond when I was pursuing this, and we just ended up working around it, so it fell off my radar. But I wanted to ask the general question here about the settings.

[jbarrez]

> This is vague to a fault. Do you mean to say that this should be set to true on at least one server?

It means that you might not want to process events on some nodes, in case your other servers have for example more resources. Each of the nodes will poll the database. If there is no need for it and you have many machines, tweaking this setting lowers the load on the db.

If no server sets it to true, no event processing will happen, meaning no events will be pumped to Elasticsearch.

Which activiti-app.properties file are your referring to? I didn't those duplications.

About the error: does it always happen? Or periodically?

[jonnyg]

In v1.4.3 the default activiti-app.properties has it on lines 182 and 444.
Reviewing the other variants (activit-app-on-premise, activiti-app-dev have it only once).

This is solely for Elastic Search? Just want to be clear – that was this thread.

Regarding our error with the database connection, the details are in #00663870.

The error we

[jbarrez]

> This is solely for Elastic Search

Yes. event.generation.enabled puts it in the database.

event.processing.enabled is for pumping them to Elastic search.

> In v1.4.3 the default activiti-app.properties has it on lines 182 and 444.

Ah you're looking at the source code. The on-premise file is the one that will eventually get in the war file (activiti-app.properties is replaced by id).