[FLINK-14434] Dispatcher#createJobManagerRunner should not start JobManagerRunner

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.2, 1.9.1, 1.10.0
• Fix Version/s: 1.8.3, 1.9.2, 1.10.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Zili Chen
• Reporter: Zili Chen
• Created: 17/Oct/19 10:11
• Updated: 29/Nov/19 15:19
• Resolved: 21/Oct/19 21:23

Description

In an edge case, let's said

1) job finished nearly immediately
2) Dispatcher has been suspended in #startJobManagerRunner after jobManagerRunner.start(); but before return jobManagerRunner;

due to

1) we put jobManagerRunnerFutures with #startJobManagerRunner finished.
2) the creation of JobManagerRunner doesn't happen in MainThread.

it is a possible execution order

1) JobManagerRunner created in akka-dispatcher thread
2) then apply Dispatcher#startJobManagerRunner
3) until jobManagerRunner.start(); and before return jobManagerRunner;
4) this thread suspended
5) job finished, execute callback on MainThread
6) jobManagerRunnerFutures.get(jobID).getNow(null) returns null because akka-dispatcher thread doesn't return jobManagerRunner;
7) it report There is a newer JobManagerRunner for the job but actually not.

*Solution*

Two perspective but we can even have them both.

1. return jobManagerRunnerFuture in #createJobManagerRunner, let #startJobManagerRunner an action
2. on JobManagerRunner created, execute #startJobManagerRunner in MainThread.

CC trohrmann

Issue Links

• links to: GitHub Pull Request #9940