Any input from anyone, please?
On Tue, 10 Oct 2023 at 09:44, Zakhar Kirpichenko <zakhar@xxxxxxxxx> wrote:
> Any input from anyone, please?
>
> It's another thing that seems to be rather poorly documented: it's unclear
> what to expect, what 'normal' behavior should be, and what can be done
> about the huge amount of writes by monitors.
>
> /Z
>
> On Mon, 9 Oct 2023 at 12:40, Zakhar Kirpichenko <zakhar@xxxxxxxxx> wrote:
>
>> Hi,
>>
>> Monitors in our 16.2.14 cluster appear to quite often run "manual
>> compaction" tasks:
>>
>> debug 2023-10-09T09:30:53.888+0000 7f48a329a700 4 rocksdb: EVENT_LOG_v1
>> {"time_micros": 1696843853892760, "job": 64225, "event": "flush_started",
>> "num_memtables": 1, "num_entries": 715, "num_deletes": 251,
>> "total_data_size": 3870352, "memory_usage": 3886744, "flush_reason":
>> "Manual Compaction"}
>> debug 2023-10-09T09:30:53.904+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:30:53.908+0000 7f48a3a9b700 4 rocksdb: (Original Log
>> Time 2023/10/09-09:30:53.910204) [db_impl/db_impl_compaction_flush.cc:2516]
>> [default] Manual compaction from level-0 to level-5 from 'paxos .. 'paxos;
>> will stop at (end)
>> debug 2023-10-09T09:30:53.908+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:30:53.908+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:30:53.908+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:30:53.908+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:30:53.908+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:30:53.908+0000 7f48a3a9b700 4 rocksdb: (Original Log
>> Time 2023/10/09-09:30:53.911004) [db_impl/db_impl_compaction_flush.cc:2516]
>> [default] Manual compaction from level-5 to level-6 from 'paxos .. 'paxos;
>> will stop at (end)
>> debug 2023-10-09T09:32:08.956+0000 7f48a329a700 4 rocksdb: EVENT_LOG_v1
>> {"time_micros": 1696843928961390, "job": 64228, "event": "flush_started",
>> "num_memtables": 1, "num_entries": 1580, "num_deletes": 502,
>> "total_data_size": 8404605, "memory_usage": 8465840, "flush_reason":
>> "Manual Compaction"}
>> debug 2023-10-09T09:32:08.972+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:08.976+0000 7f48a3a9b700 4 rocksdb: (Original Log
>> Time 2023/10/09-09:32:08.977739) [db_impl/db_impl_compaction_flush.cc:2516]
>> [default] Manual compaction from level-0 to level-5 from 'logm .. 'logm;
>> will stop at (end)
>> debug 2023-10-09T09:32:08.976+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:08.976+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:08.976+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:08.976+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:08.976+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:08.976+0000 7f48a3a9b700 4 rocksdb: (Original Log
>> Time 2023/10/09-09:32:08.978512) [db_impl/db_impl_compaction_flush.cc:2516]
>> [default] Manual compaction from level-5 to level-6 from 'logm .. 'logm;
>> will stop at (end)
>> debug 2023-10-09T09:32:12.764+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:12.764+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:12.764+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:12.764+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:12.764+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:32:12.764+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.028+0000 7f48a329a700 4 rocksdb: EVENT_LOG_v1
>> {"time_micros": 1696844009033151, "job": 64231, "event": "flush_started",
>> "num_memtables": 1, "num_entries": 1430, "num_deletes": 251,
>> "total_data_size": 8975535, "memory_usage": 9035920, "flush_reason":
>> "Manual Compaction"}
>> debug 2023-10-09T09:33:29.044+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.048+0000 7f48a3a9b700 4 rocksdb: (Original Log
>> Time 2023/10/09-09:33:29.049585) [db_impl/db_impl_compaction_flush.cc:2516]
>> [default] Manual compaction from level-0 to level-5 from 'paxos .. 'paxos;
>> will stop at (end)
>> debug 2023-10-09T09:33:29.048+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.048+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.048+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.048+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.048+0000 7f4899286700 4 rocksdb:
>> [db_impl/db_impl_compaction_flush.cc:1443] [default] Manual compaction
>> starting
>> debug 2023-10-09T09:33:29.048+0000 7f48a3a9b700 4 rocksdb: (Original Log
>> Time 2023/10/09-09:33:29.050355) [db_impl/db_impl_compaction_flush.cc:2516]
>> [default] Manual compaction from level-5 to level-6 from 'paxos .. 'paxos;
>> will stop at (end)
>>
>> I have removed a lot of interim log messages to save space.
>>
>> During each compaction the monitor process writes approximately 500-600
>> MB of data to disk over a short period of time. These writes add up to tens
>> of gigabytes per hour and hundreds of gigabytes per day.
>>
>> Monitor rocksdb and compaction options are default:
>>
>> "mon_compact_on_bootstrap": "false",
>> "mon_compact_on_start": "false",
>> "mon_compact_on_trim": "true",
>> "mon_rocksdb_options":
>> "write_buffer_size=33554432,compression=kNoCompression,level_compaction_dynamic_level_bytes=true",
>>
>> Is this expected behavior? Is this something I can adjust in order to
>> extend the system storage life?
>>
>> Best regards,
>> Zakhar
>>
>
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