ingester: use a 64-bit hash to avoid collisions #5276
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mdisibio
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Jun 13, 2025
We had this issue in the distributor, it it can happen in the ingester too with live traces.
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@mdisibio I've added a test to check for collisions. I've also run the same test in main and the same span IDs where found in multiple traces, so I can confirm that this fixes the issue for live traces. |
mdisibio
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Jun 16, 2025
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* ingester: use a 64-bit hash to avoid collisions We had this issue in the distributor, it it can happen in the ingester too with live traces. * Update changelog * Add test for live traces collision
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* ingester: use a 64-bit hash to avoid collisions We had this issue in the distributor, it it can happen in the ingester too with live traces. * Update changelog * Add test for live traces collision
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* ingester: use a 64-bit hash to avoid collisions We had this issue in the distributor, it it can happen in the ingester too with live traces. * Update changelog * Add test for live traces collision
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We had this issue in the distributor (#5186), it it can happen in the ingester too with live traces.
In the ingester we use a map to store live traces where the key is a hash of the Trace ID. Because we were using 32-bit hashes, in cases where tens of thousands of traces were pushed, there was a high chance of collision in which case spans from different traces would be incorrectly combined. By using a 64-bit we minimize the collision chance.
What this PR does:
Which issue(s) this PR fixes:
Fixes #
Checklist
CHANGELOG.mdupdated - the order of entries should be[CHANGE],[FEATURE],[ENHANCEMENT],[BUGFIX]