exporter: fix flaky Test_rateLimitExport with polling #4280
Conversation
This file contains hidden or 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
Replace fixed sleep with polling-based synchronization to eliminate timing-dependent race condition that caused intermittent test failures. The test was using a fixed 200ms sleep which created a window where multiple ticker intervals could fire, causing off-by-one errors in event counts. The new approach polls every 10ms until expected events are received, with a 500ms timeout for robustness. Fixes cilium#2789 Signed-off-by: Farooq Shaikh <[email protected]>
calghar
force-pushed
the
fix/flaky-rate-limit-test-2789
branch
from
299f80b to
57d5e47
Compare
calghar
changed the title
Contributor
Author
|
This PR fixes a flaky test with no user-facing changes. Could a maintainer please add the |
sayboras
added
release-note/ci
mtardy
approved these changes
Nov 21, 2025
Member
mtardy
left a comment
mtardy
left a comment
There was a problem hiding this comment.
lgtm as well, only a few golang nits. Will merge this later, give you some time to update the patch or not depending on what you prefer! thanks
Comment on lines
+125
to
+126
| func countEvents(eventsJSON []string) (int, int, uint64) { | ||
| gotEvents, gotRateLimitInfo, gotDropped := 0, 0, uint64(0) |
Member
There was a problem hiding this comment.
I'd used the named return parameters feature if you are anyway going to do it
Suggested change
| func countEvents(eventsJSON []string) (int, int, uint64) { | |
| gotEvents, gotRateLimitInfo, gotDropped := 0, 0, uint64(0) | |
| func countEvents(eventsJSON []string) (gotEvents int, gotRateLimitInfo int, gotDropped uint64) { |
Comment on lines
+252
to
+257
| pollLoop: | ||
| for { | ||
| gotEvents, gotRateLimitInfo, _ := countEvents(results.items) | ||
| if gotEvents >= tt.wantEvents && gotRateLimitInfo >= tt.wantRateLimitInfo { | ||
| // We have all the expected output, proceed to cleanup and assertions. | ||
| break pollLoop |
Member
There was a problem hiding this comment.
I don't think you need to name it in your case?
Suggested change
| pollLoop: | |
| for { | |
| gotEvents, gotRateLimitInfo, _ := countEvents(results.items) | |
| if gotEvents >= tt.wantEvents && gotRateLimitInfo >= tt.wantRateLimitInfo { | |
| // We have all the expected output, proceed to cleanup and assertions. | |
| break pollLoop | |
| for { | |
| gotEvents, gotRateLimitInfo, _ := countEvents(results.items) | |
| if gotEvents >= tt.wantEvents && gotRateLimitInfo >= tt.wantRateLimitInfo { | |
| // We have all the expected output, proceed to cleanup and assertions. | |
| break |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
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.
Summary
This PR fixes the flaky Test_rateLimitExport test by replacing the fixed sleep duration with a polling-based synchronization mechanism, addressing the timing race condition reported in #2789.
Related Issue
Fixes #2789
Root Cause
The test used a fixed 200ms sleep which allowed multiple rate limiter ticker intervals (50ms each) to fire during the wait period. This created a timing window where:
Proposed Changes
Testing Performed
Backward Compatibility
No breaking changes. The fix only modifies the test implementation, not the rate limiter functionality itself.
Changelog