[FLINK-7078] Support fencing tokens to filter out outdated messages

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Done
• Fix Version/s: 1.4.0
• Component/s: Runtime / Coordination
• Labels: flip-6
• Assignee: Till Rohrmann
• Reporter: Till Rohrmann
• Created: 03/Jul/17 22:23
• Updated: 03/Sep/17 21:38
• Resolved: 03/Sep/17 21:38

Description

In order to guard against split brain situations, it is important that RPC calls are guarded with a fencing token. The sender attaches his fencing token to a RPC message which is then used on the receiver side to compare against the expected fencing token. An example is the leader session ID which we attach to all critical RPC messages.

So far, in the Flip-6 code base we send fencing tokens explicitly. This is not only cumbersome but also error-prone because you have to do it for all RPCs. Therefore, it would be better if we could automatically compare fencing tokens for a given RPC from a given source. This should ideally happen on the level of the RPC server.

Issue Links

• links to: GitHub Pull Request #4578