QQ: handle case where a stale read request results in member crash. (backport #12636) #12637
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Outdated suggestions cannot be applied.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.
It is possible for a slow running follower with local consumers to crash after a snapshot installation as it tries to read an entry from its log that is no longer there (as it has been consumed and completed by another node but still refers to prior consumers on the current node).
This commit makes the log effect callback function more defensive to check that the number of commands returned by the log effect isn't different from what was requested. if it is different we consider this a stale read request and return no further effects.
Fixes #12635
This is an automatic backport of pull request #12636 done by Mergify.