[CURATOR-104] LeaderSelector issue after losing ZooKeeper leader

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.1
• Fix Version/s: 2.4.2
• Assignee: Jordan Zimmerman
• Reporter: Greg Moulliet
• Created: 18/Apr/14 20:14
• Updated: 23/May/23 02:57
• Resolved: 21/Apr/14 19:53

Description

LeaderSelectors are not re-attempting leadership after a ZooKeeper leader is stopped and a client with leadership is stopped.

I have a client process running on 2 servers. Each process is using LeaderSelectors for the same set of leaderPaths.

The scenario:
1 - Both clients running, with one client being the leader of each path (2 children are under each leaderPath)
2 - Stop the ZooKeeper leader
3 - All clients temporarily lose leadership (0 children are under each leaderPath)
4 - Leadership is regained by the same clients that had leadership in step 1 (1 child is under each leaderPath)
5 - Stop a client with leadership
6 - No other clients pick up leadership of the leaderPaths from step 5 (0 children are under each leaderPath)
Sometimes, a client will pick up one of the leaderPaths, but not more than one.

I’m using Curator 2.4.1 and ZooKeeper 3.4.5.
I originally saw the issue with Curator 2.3.0, and was hoping it was the same as https://issues.apache.org/jira/browse/CURATOR-73.

Issue Links

• fixes: CURATOR-15 LeaderSelector may (undetectably) fail to elect