[NIFI-9293] Stateless engine does not stop processors properly

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.16.0
• Component/s: NiFi Stateless
• Assignee: Mark Payne
• Reporter: Peter Turcsanyi
• Created: 11/Oct/21 07:49
• Updated: 25/Jan/22 16:41
• Resolved: 24/Jan/22 21:09

Description

When the embedding application calls StatelessDataflow.shutdown() to stop the stateless flow and all its processors, then the expected behaviour would be (similar to traditional NiFi):

• call @OnUnscheduled method(s) of the processor
• wait for onTrigger() to finish up
• call @OnStopped method(s) of the processor

Currently @OnUnscheduled is not called at all and @OnStopped gets called while onTrigger() is still running.
These may lead to improper shutdown of the components: e.g. ConsumeJMS stays connected to the message broker after is has been stopped (up until the JVM exits).
It is more problematic for long-running embedding applications that can start/stop flows dynamically within their JVM uptime (like Kafka Connect and NiFi Stateless connectors).

Issue Links

• links to: GitHub Pull Request #5706