Fix flaky test_write_failover in test_merge_tree_s3_failover#96716
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alexey-milovidov merged 1 commit intomasterfrom Feb 12, 2026
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Fix flaky test_write_failover in test_merge_tree_s3_failover#96716alexey-milovidov merged 1 commit intomasterfrom
alexey-milovidov merged 1 commit intomasterfrom
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The S3 proxy endpoint counted all HTTP methods (GET, POST, PUT, DELETE) toward its fail counter. When a previous INSERT failed partway through writing part files, ClickHouse would clean up the partially written files via DELETE requests. These background DELETE/GET requests could race with the next iteration's `fail_request()` call, consuming the counter before the INSERT's PUT requests, causing the INSERT to succeed earlier than expected. The fix adds optional HTTP method filtering to the proxy's `fail_request` endpoint (`/fail_request/<N>/<method>`). The `test_write_failover` test now uses `fail_request(N, "PUT")` to only count PUT requests, so background cleanup operations no longer interfere with the counter. Other tests (`test_move_failover`, `test_retry_loading_parts`, `test_throttle_retry`) are unaffected as they continue using the unfiltered `fail_request(N)`. CI report: https://s3.amazonaws.com/clickhouse-test-reports/json.html?PR=96705&sha=8a70737430373209132a005dc88f94f9bd2962af&name_0=PR&name_1=Integration%20tests%20%28arm_binary%2C%20distributed%20plan%2C%202%2F4%29 Closes #96649 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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The S3 proxy endpoint's fail counter was consumed by background GET/DELETE requests (e.g. cleanup of partially written parts from failed INSERTs), causing the INSERT to succeed earlier than expected.
Added optional HTTP method filtering to the proxy's
fail_requestendpoint sotest_write_failovercounts only PUT requests. Other tests in the same suite are unaffected (they use unfilteredfail_request).CI report: https://s3.amazonaws.com/clickhouse-test-reports/json.html?PR=96705&sha=8a70737430373209132a005dc88f94f9bd2962af&name_0=PR&name_1=Integration%20tests%20%28arm_binary%2C%20distributed%20plan%2C%202%2F4%29
#96705
Closes #96649
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