PRW2: Fix data corruption caused by shallow copy#7337
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friedrichg merged 3 commits intoMar 9, 2026
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Signed-off-by: SungJin1212 <tjdwls1201@gmail.com>
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* Fix data corruption casused by shallow copy Signed-off-by: SungJin1212 <tjdwls1201@gmail.com> * fix test Signed-off-by: SungJin1212 <tjdwls1201@gmail.com> * fix lint Signed-off-by: SungJin1212 <tjdwls1201@gmail.com> --------- Signed-off-by: SungJin1212 <tjdwls1201@gmail.com>
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This PR fixes a data corruption in the push handler by using a deep copy instead of a shallow copy. This ensures that a new backing array is allocated for the V1 request, decoupling it from the V2 request's lifecycle.
The problem
I have noticed that the data has been corrupted when Prometheus sends V1 and V2 requests with different users (V1 request for user1 and V2 request for user2); the samples in the V2 request are overwritten by V1 or vice versa.
The bug was caused by a shallow copy of Samples and Histograms when converting V2 requests to V1, leading to memory overlap and data corruption when objects were reused from the
sync.Pool.In the
convertV2RequestToV1function, the code was directly assigning slices from the V2 request to the V1 structure. Since these slices share the same underlying memory (backing array), when a V2 request was returned to thesync.Pooland subsequently overwritten by a new incoming request, the V1 request (which was still referencing that memory) would see its data change unexpectedly.The test
TestIngest_PRW2_MemoryIndependenceshows this situation.Which issue(s) this PR fixes:
Fixes #
Checklist
CHANGELOG.mdupdated - the order of entries should be[CHANGE],[FEATURE],[ENHANCEMENT],[BUGFIX]