Re: About to add WAL write/fsync statistics to pg_stat_wal view
Masahiro Ikeda <ikedamsh@oss.nttdata.com>
From: Masahiro Ikeda <ikedamsh@oss.nttdata.com>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>, Masahiko Sawada
<sawada.mshk@gmail.com>, Li Japin <japinli@hotmail.com>,
kuroda.hayato@fujitsu.com, "David G. Johnston" <david.g.johnston@gmail.com>
Date: 2021-02-15T02:32:12Z
Lists: pgsql-hackers
On 2021-02-08 13:01, Fujii Masao wrote: > On 2021/02/05 8:45, Masahiro Ikeda wrote: >> I pgindented the patches. > > Thanks for updating the patches! Thanks for checking the patches. > + <function>XLogWrite</function>, which nomally called by an > + <function>issue_xlog_fsync</function>, which nomally called by > an > > Typo: "nomally" should be "normally"? Yes, I'll fix it. > + <function>XLogFlush</function> request(see <xref > linkend="wal-configuration"/>) > + <function>XLogFlush</function> request(see <xref > linkend="wal-configuration"/>), > > Isn't it better to add a space character just after "request"? Thanks, I'll fix it. > + INSTR_TIME_SET_CURRENT(duration); > + INSTR_TIME_SUBTRACT(duration, start); > + WalStats.m_wal_write_time = INSTR_TIME_GET_MICROSEC(duration); > > If several cycles happen in the do-while loop, m_wal_write_time should > be > updated with the sum of "duration" in those cycles instead of > "duration" > in the last cycle? If yes, "+=" should be used instead of "=" when > updating > m_wal_write_time? > + INSTR_TIME_SET_CURRENT(duration); > + INSTR_TIME_SUBTRACT(duration, start); > + WalStats.m_wal_sync_time = INSTR_TIME_GET_MICROSEC(duration); > > Also "=" should be "+=" in the above? Yes, they are my mistake when changing the unit from milliseconds to microseconds. Regards, -- Masahiro Ikeda NTT DATA CORPORATION
Commits
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Send statistics collected during shutdown checkpoint to the stats collector.
- b82640df0062 14.0 landed
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Force to send remaining WAL stats to the stats collector at walwriter exit.
- 33394ee6f243 14.0 landed
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Track total amounts of times spent writing and syncing WAL data to disk.
- ff99918c625a 14.0 landed
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Retry short writes when flushing WAL.
- 79ce29c734c6 9.4.0 cited