fix(query-frontend): ensure slow query and stats logging on request failures#8618
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GiedriusS merged 2 commits intothanos-io:mainfrom Jan 22, 2026
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Ensure we log slow queries and query statistics regardless of how the request completes Signed-off-by: Pavel Litvyak <pvlltvk@gmail.com>
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Thanks for the ping and sorry for the delay. It's on my todo list. |
…uery Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>
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PR thanos-io#8618 moved slow query logging into a defer and switched from using w.Header() (ResponseWriter headers) to resp.Header (round-trip response headers). The X-Thanos-Trace-Id header is set on w.Header() by the tracing middleware before the handler runs, so it was never present in resp.Header, causing trace IDs to be missing from slow query logs. Pass w.Header() to reportQueryStatsAndSlowQueries instead of the response object so the trace ID is available on both success and error paths. Fixes: thanos-io#8760 Signed-off-by: Pavel Litvyak <pvlltvk@gmail.com>
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This PR fix the query-frontend handler to guarantee that slow query logging and query statistics are reported even when requests fail or panic.
Fixes: #6219
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internal/cortex/frontend/transport/handler.go:reportQueryStatsAndSlowQueriesfunction for clarityreportQueryStatsAndSlowQueriesin a defer to ensure it runs regardless of how the request completes (success, error, or panic)reportQueryStatswhere return values fromaddStatsToLogMessageandaddQueryRangeToLogMessagewere ignored, causing stats and query range to be missing from log outputVerification
make lintmake format