Fix poison pill bug: Make retry heap unbounded#2012
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the-mann wants to merge 2 commits intosender-block-on-failurefrom
Closed
Fix poison pill bug: Make retry heap unbounded#2012the-mann wants to merge 2 commits intosender-block-on-failurefrom
the-mann wants to merge 2 commits intosender-block-on-failurefrom
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- TestPoisonPillScenario: Validates continuous batch generation with 10 denied + 1 allowed log group - TestSingleDeniedLogGroup: Baseline test with 1 denied + 1 allowed log group - TestRetryHeapSmallerThanFailingLogGroups: Demonstrates deadlock when heap size < failing log groups (SKIPPED) The third test intentionally deadlocks to prove the bug exists when: - Retry heap size = concurrency (2) - Number of failing log groups (10) > heap size (2) - Workers block trying to push to full heap - System deadlocks, starving allowed log group
Remove max size constraint from retry heap to prevent deadlock when failing log groups exceed concurrency limit. Changes: - Remove maxSize and semaphore from retryHeap struct - Make Push() non-blocking (no semaphore wait) - Remove semaphore release from PopReady() - Update NewRetryHeap() to ignore maxSize parameter (kept for API compatibility) - Update TestRetryHeap_SemaphoreBlockingAndUnblocking -> TestRetryHeap_UnboundedPush - Update TestRetryHeapSmallerThanFailingLogGroups to validate fix Before: With concurrency=2 and 10 failing log groups, retry heap (size=2) would fill up, causing workers to block on Push(), leading to deadlock. After: Retry heap is unbounded, allowing all failed batches to be queued without blocking workers. Allowed log groups continue publishing normally. Test results: - TestRetryHeapSmallerThanFailingLogGroups: PASS (5/5 allowed batches published) - Heap grew to size 28 (beyond concurrency limit of 2) - No deadlock or starvation
This was referenced Feb 11, 2026
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Summary
Fix deadlock when failing log groups exceed concurrency limit by making the retry heap unbounded.
Problem
With bounded retry heap (size = concurrency):
Solution
Make retry heap unbounded:
Changes
maxSizeandsemaphorefrom retryHeap structPush()non-blocking (no semaphore wait)PopReady()NewRetryHeap()to ignore maxSize parameter (kept for API compatibility)TestRetryHeap_SemaphoreBlockingAndUnblocking→TestRetryHeap_UnboundedPushTestRetryHeapSmallerThanFailingLogGroupsto validate fixTest Results
Before Fix: Test deadlocked after 30s with all goroutines blocked
After Fix: ✅ Test PASSES
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