Gracefully handle short lived outages by holding RPC calls #2175
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
| return false, nil | ||
|
|
||
| // Gate the request until there is a leader | ||
| if firstCheck.IsZero() { |
There was a problem hiding this comment.
Why not just set firstCheck to time.Now() above?
There was a problem hiding this comment.
It's a nano-optimization.
|
@armon this looks great! One tiny comment and it would be good to add a unit test for this :-) |
slackpad
pushed a commit
that referenced
this pull request
Jul 11, 2016
This adds some extra tests for #2175.
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Outdated suggestions cannot be applied.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.
This PR modifies the RPC forwarding behavior from a fast-fail in the case there is no known leader, to adding a small hold period. In the case of a short lived outage, this will cause RPCs to return successfully. In the case of a long lived outage, the call will still error out in a reasonable time. It also prevents callers who have while-true retry logic from abusing the system.