Handle view changes during election #263
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Created test cases for the scenarios mentioned in the GitHub issue and the fixes. Elected leader leaving before the voting thread has finished. This causes a liveness issue on both ELECTION and ELECTION2. We can fix this by stopping the voting thread before starting it again. Scenarios the coordinator leaves before finishing the election process and a majority still exists. ELECTION algorithm has a liveness issue in this case, since it does not take into account changes in the view coordinator. We handle this case by calculating if the coordinator has changed between views, there is a majority, it is currently the coordinator, and there is no leader elected. Close jgroups-extras#259.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
More details on #259.
When the elected leader leaves before the voting thread has finished and a majority is present. This causes a liveness issue on both ELECTION and ELECTION2. We can fix this by stopping the voting thread before starting it again.
Scenarios the coordinator leaves before finishing the election process and a majority still exists. The ELECTION algorithm has a liveness issue since it does not verify changes in the view coordinator. We handle this case by calculating if the coordinator has changed between views, there is a majority, it is currently the coordinator, and there is no leader.