Add metrics for broken files during async distributed sends#23885
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alexey-milovidov merged 2 commits intoClickHouse:masterfrom May 5, 2021
Merged
Add metrics for broken files during async distributed sends#23885alexey-milovidov merged 2 commits intoClickHouse:masterfrom
alexey-milovidov merged 2 commits intoClickHouse:masterfrom
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Number of files for asynchronous insertion into Distributed tables that has been marked as broken. This metric will starts from 0 on start. Number of files for every shard is summed.
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Previously it was possible to have a race while updating files_count/bytes_count, since INSERT updates it those counters from one thread and the same metrics are updated from filesystem in a separate thread, and even though the access is synchronized with the mutex it avoids the race only for accessing the variables not the logical race, since it is possible that getFiles() from a separate thread will increment counters and later addAndSchedule() will increment them again. Here you can find an example of this race [1]. [1]: https://pastila.nl/?00950e00/41a3c7bbb0a7e75bd3f2922c58b02334 Note, that I analyzed logs from production system with lots of async Distributed INSERT and everything is OK there, even though the logs contains the following: 2022.11.20 02:21:15.459483 [ 11528 ] {} <Trace> v21.dist_out.DirectoryMonitor: Files set to 35 (was 34) 2022.11.20 02:21:15.459515 [ 11528 ] {} <Trace> v21.dist_out.DirectoryMonitor: Bytes set to 4035418 (was 3929008) 2022.11.20 02:21:15.819488 [ 11528 ] {} <Trace> v21.dist_out.DirectoryMonitor: Files set to 1 (was 2) 2022.11.20 02:21:15.819502 [ 11528 ] {} <Trace> v21.dist_out.DirectoryMonitor: Bytes set to 190072 (was 296482) As you may see it first increases the counters and next update decreases (and 4035418-3929008 == 296482-190072) Refs: ClickHouse#23885 Reported-by: @tavplubix Signed-off-by: Azat Khuzhin <[email protected]>
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Add
broken_data_files/broken_data_compressed_bytesintosystem.distribution_queue. Add metric for number of files for asynchronous insertion into Distributed tables that has been marked as broken (BrokenDistributedFilesToInsert).