[CURATOR-168] Background protected mode incorrectly sets Event name to just ZNode name. Should be full path.

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.7.0
• Fix Version/s: 2.8.0
• Component/s: Recipes
• Environment: operating system:ubuntu
• Assignee: Unassigned
• Reporter: zhaogang
• Created: 27/Nov/14 09:19
• Updated: 26/Nov/19 14:42
• Resolved: 21/Apr/15 01:17

Description

We use LeaderLatch for leader election within our several zookeeper clients,but sometimes our leaderLatch stopped to work due to a error "Background exception was not retry-able or retry gave up java.lang.IllegalArgumentException: Path must start with / characte".

To found the reason we tracked the execution of program in class LeaderLatch with debug mode,we found the code "setNode(event.getName());" in line 487 of LeaderLatch.class in which "event.getName()" code sometimes didn't return the full path of the znode but only return the last part of the full path,like "_c_b1097329-4a77-493b-806c-5c888067eeab-latch-0000004068", but the full path should be "/api1/leaders/_c_b1097329-4a77-493b-806c-5c888067eeab-latch-0000004068".

So the when event.getName()=="_c_b1097329-4a77-493b-806c-5c888067eeab-latch-0000004068", the program will fail to go through the codes below:
1.LeaderLatch.checkLeadership() line 526
2.ZKPaths.getNodeFromPath() line 61
3.PathUtils.validatePath(path) line 46
And then the LeaderLatch stopped to work.

Issue Links

• is duplicated by: CURATOR-165 LeaderLatch.checkLeadership(LeaderLatch.java:478) will throw a exception, then no leader will be elected.
• is related to: SPARK-20884 Spark' masters will be both standby due to the bug of curator