HDDS-4580. Datanode can be stuck in leader not ready state after restart #1690
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Outdated suggestions cannot be applied.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.
What changes were proposed in this pull request?
On restart the transactions are reapplied for an existing ratis pipeline. ContainerStateMachine#applyTransaction while processing future can throw NullPointerException leading to the future being completed exceptionally.
In the above code snippet trx.getStateMachineContext() will be null during restart and this fails the future itself without updating the applyTransactionCompletionMap. As a result the lastAppliedIndex is not updated for the server and server is stuck in leader not ready state.
What is the link to the Apache JIRA
https://issues.apache.org/jira/browse/HDDS-4580
How was this patch tested?
Existing UT