fix(inputs.tail): Fix data race when cleaning up unused tailers#17613
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mstrandboge merged 5 commits intoSep 12, 2025
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Remove Tell() call during tailer cleanup to avoid race condition with the tail library's internal file reopening goroutine. The race occurred when Tell() tried to read the file handle while the tail library was concurrently modifying it during reopen(). This fix prioritizes stability by not saving offsets for files that no longer match glob patterns, as these are typically rotated logs that won't return with the same name. Fixes influxdata#17571
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Thanks @skartikey! One question in the code...
… preserve offsets Stop the tailer before calling Tell() during cleanup to eliminate the race condition while still preserving file offsets for state persistence. This ensures that files temporarily removed from glob patterns can resume from the correct position if they return.
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Thanks for the update @skartikey! Looks good to me, just some style comments...
Co-authored-by: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
Co-authored-by: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
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Download PR build artifacts for linux_amd64.tar.gz, darwin_arm64.tar.gz, and windows_amd64.zip. 📦 Click here to get additional PR build artifactsArtifact URLs |
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Co-authored-by: Sven Rebhan <36194019+srebhan@users.noreply.github.com> (cherry picked from commit 2586690)
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…uxdata#17613) Co-authored-by: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
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Summary
Fixes a critical data race condition in the tail input plugin that was blocking multiple dependency updates due to increased detection frequency with testify v1.11.x.
The race condition occurred in
cleanupUnusedTailers()between:Tell()to get the current file offsetreopen()which modifies the file handleSolution
Removed the
Tell()call during cleanup of tailers for files that no longer match glob patterns. This is a safe trade-off because:app.log→app.log.1) that won't return with the same nameChecklist
Related issues
resolves #17571