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| author | Andres Freund <andres@anarazel.de> | 2025-03-18 10:52:33 -0400 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2025-03-18 11:54:01 -0400 |
| commit | 55b454d0e14084c841a034073abbf1a0ea937a45 (patch) | |
| tree | 4bdd85a6acb02123b35bfeb1c33c1c071be30ba1 /doc/src | |
| parent | 549ea06e4217aca10d3a73dc09cf5018c51bc23a (diff) | |
| download | postgresql-55b454d0e14084c841a034073abbf1a0ea937a45.tar.gz postgresql-55b454d0e14084c841a034073abbf1a0ea937a45.zip | |
aio: Infrastructure for io_method=worker
This commit contains the basic, system-wide, infrastructure for
io_method=worker. It does not yet actually execute IO, this commit just
provides the infrastructure for running IO workers, kept separate for easier
review.
The number of IO workers can be adjusted with a PGC_SIGHUP GUC. Eventually
we'd like to make the number of workers dynamically scale up/down based on the
current "IO load".
To allow the number of IO workers to be increased without a restart, we need
to reserve PGPROC entries for the workers unconditionally. This has been
judged to be worth the cost. If it turns out to be problematic, we can
introduce a PGC_POSTMASTER GUC to control the maximum number.
As io workers might be needed during shutdown, e.g. for AIO during the
shutdown checkpoint, a new PMState phase is added. IO workers are shut down
after the shutdown checkpoint has been performed and walsender/archiver have
shut down, but before the checkpointer itself shuts down. See also
87a6690cc69.
Updates PGSTAT_FILE_FORMAT_ID due to the addition of a new BackendType.
Reviewed-by: Noah Misch <noah@leadboat.com>
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Co-authored-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Discussion: https://postgr.es/m/20210223100344.llw5an2aklengrmn@alap3.anarazel.de
Discussion: https://postgr.es/m/stj36ea6yyhoxtqkhpieia2z4krnam7qyetc57rfezgk4zgapf@gcnactj4z56m
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 42e96b96f21..c749bc0631a 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -2689,6 +2689,25 @@ include_dir 'conf.d' </listitem> </varlistentry> + <varlistentry id="guc-io-workers" xreflabel="io_workers"> + <term><varname>io_workers</varname> (<type>int</type>) + <indexterm> + <primary><varname>io_workers</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + Selects the number of I/O worker processes to use. The default is + 3. This parameter can only be set in the + <filename>postgresql.conf</filename> file or on the server command + line. + </para> + <para> + Only has an effect if <xref linkend="guc-io-method"/> is set to + <literal>worker</literal>. + </para> + </listitem> + </varlistentry> </variablelist> </sect2> |