fix: TSI concurrent write and iteration fatal errors#27344
Merged
gwossum merged 1 commit intomaster-1.xfrom Apr 9, 2026
Merged
fix: TSI concurrent write and iteration fatal errors#27344gwossum merged 1 commit intomaster-1.xfrom
gwossum merged 1 commit intomaster-1.xfrom
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Fix `fatal error: concurrent map iteration and map write` errors in TSI code. This appears to have been introduced with #27343. This was a backport from main-2.x. A PR comment in #27343 indicates this PR is not necessary for correctness in master-1.x at this time. To fix the issue, #27343 is rolled back. A test (TestLogFile_TagValueIterator_ConcurrentWrite) is able consistently reproduce the error when #27343 is present. This bug was introduced in v1.12.3 and does impact previous versions. Closes: #27343
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Pull request overview
Fixes a fatal error: concurrent map iteration and map write panic in TSI log file tag value iteration by ensuring the relevant read lock is held during snapshot creation, and adds a regression test that reliably reproduces the issue when the lock is released too early.
Changes:
- Hold
LogFile’sRLockfor the full duration ofTagValueIterator()’s snapshot/iterator creation. - Add a concurrent writer/reader regression test for
TagValueIterator()vsAddSeriesList().
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
tsdb/index/tsi1/log_file.go |
Keeps RLock held while building the tag value iterator snapshot to prevent concurrent map iteration/write panics. |
tsdb/index/tsi1/log_file_test.go |
Adds a regression test that concurrently mutates and iterates tag values to catch the panic reliably. |
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| // Ensure TagValueIterator is safe to call concurrently with AddSeriesList. | ||
| // Regression test for a "concurrent map iteration and map write" fatal | ||
| // introduced when LogFile.TagValueIterator released its RLock before the | ||
| // underlying logTagKey.tagValues map was snapshotted. This is able to | ||
| // consistently reproduce the fatal error introduced by #26372. | ||
| func TestLogFile_TagValueIterator_ConcurrentWrite(t *testing.T) { |
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davidby-influx
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If the test fails, it panics, and the test harness recovers?
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Yes, the Go |
gwossum
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Fix
fatal error: concurrent map iteration and map writeerrors in TSI code. This appears to have been introduced with #27343. This was a backport from main-2.x. A PR comment in #27343 indicates this PR is not necessary for correctness in master-1.x at this time.To fix the issue, #27343 is rolled back. A test
(TestLogFile_TagValueIterator_ConcurrentWrite) is able consistently reproduce the error when #27343 is present.
This bug was introduced in v1.12.3 and does impact previous versions.
Closes: #27343