Oozie: Does oozie generate output-events?
The official Oozie documentation for Oozie Coordinator is not very clear on the exact purpose of the output-events element. However, the book "Apache Oozie: The Workflow Scheduler for Hadoop" mentions the following:
During reprocessing of a coordinator, Oozie tries to help the retry attempt by cleaning up the output directories by default. For this, it uses the
<output-events>specification in the coordinator XML to remove the old output before running the new attempt. Users can override this default behavior using the–noCleanupoption.
So, in summary:
- No, files specified in
output-eventsare not automatically created by Oozie, you need to create those files in your Oozie workflow actions. - The
output-eventsconfiguration is for giving Oozie information on what files will be created by your Oozie workflow actions, which Oozie would use to cleanup files when rerunning/reprocessing a coordinator.
Always the actions generate the data, these settings are just for control.You'll find some examples here