[SAMZA-1084] User thread does not see errors from the processor thread when using the StreamProcessor API

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Resolved
• Fix Version/s: 0.13.0
• Assignee: Navina Ramesh
• Reporter: Navina Ramesh
• Created: 08/Feb/17 19:52
• Updated: 03/May/17 22:14
• Resolved: 03/May/17 22:14

Description

The current user model for StreamProcessor API allows the user to start (asynchronous) and stop processor. awaitStart allows the user to wait until the processor actually initializes and starts processing messages. There are certain limitations to this API:
1. In case the processor fails during processing or prior to processing, the error is not propagated to the user context. It is very hard to troubleshoot and take action on error/shutdown.
2. There is also no way for the user to check the status of the processor.
3. (More of implementation detail than an API issue) Another issue is that we are using an Executor to run the container in a separate thread. The container uses another Executor to run the tasks. We need to understand the performance impact of using 2 levels of Executors in a single StreamProcessor instance.

Issue Links

• is related to: SAMZA-1147 ZkJobCoordinator does not honor the interface contract of JobCoordinator
• is required by: SAMZA-1064 Standalone Samza with Zookeeper for Coordination
• links to: GitHub Pull Request #54