database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2026-10-28 02:33:10 +03:00
Code Activity

doc: Improve description of pg_stat_activity.backend_type

Browse Source 
The documentation of pg_stat_activity used an incomplete list of values
for backend_type.  While on it, it is improved to use an itemized list,
now ordered alphabetically, with a short description about each item.

Author: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-By: Michael Paquier <michael@paquier.xyz>
Reviewed-By: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/5e94c0196084f648ae6a00107125494f5804318a.camel@cybertec.at
This commit is contained in:
Michael Paquier
2026-07-23 16:09:13 +09:00
parent a49b6a6109
commit abbd74ce87
1 changed files with 155 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

165
doc/src/sgml/monitoring.sgml
View File

@@ -1057,16 +1057,161 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
<structfield>backend_type</structfield> <type>text</type>
</para>
<para>
Type of current backend. Possible types are
<literal>autovacuum launcher</literal>, <literal>autovacuum worker</literal>,
<literal>logical replication launcher</literal>,
<literal>logical replication worker</literal>,
<literal>parallel worker</literal>, <literal>background writer</literal>,
<literal>client backend</literal>, <literal>checkpointer</literal>,
<literal>archiver</literal>, <literal>standalone backend</literal>,
<literal>startup</literal>, <literal>walreceiver</literal>,
<literal>walsender</literal>, <literal>walwriter</literal> and
<literal>walsummarizer</literal>.
Type of current backend. Possible types are:
<itemizedlist>
<listitem>
<para>
<literal>archiver</literal>: The WAL archiver, active when
<xref linkend="guc-archive-mode"/> is enabled.
</para>
</listitem>
<listitem>
<para>
<literal>autovacuum launcher</literal>: The background process that
launches autovacuum workers, active when
<xref linkend="guc-autovacuum"/> is <literal>on</literal>.
</para>
</listitem>
<listitem>
<para>
<literal>autovacuum worker</literal>: A background process running
<command>VACUUM</command> or <command>ANALYZE</command> on a single
table.
</para>
</listitem>
<listitem>
<para>
<literal>background writer</literal>: The background process that
makes sure that there are enough clean buffers in shared buffers.
</para>
</listitem>
<listitem>
<para>
<literal>checkpointer</literal>: The background process that
performs <link linkend="wal-configuration">checkpoints</link>
regularly.
</para>
</listitem>
<listitem>
<para>
<literal>client backend</literal>: The server process performing
work for a regular database connection.
</para>
</listitem>
<listitem>
<para>
<literal>datachecksums launcher</literal>: The background process
that launches data checksum workers.
</para>
</listitem>
<listitem>
<para>
<literal>datachecksums worker</literal>: A background process that
calculates data checksums for all pages in one database.
</para>
</listitem>
<listitem>
<para>
<literal>io worker</literal>: A background process performing
asynchronous I/O, active when <xref linkend="guc-io-method"/> is set
to <literal>worker</literal>.
</para>
</listitem>
<listitem>
<para>
<literal>logical replication apply worker</literal>: A background
process that applies data modifications on a logical subscriber.
</para>
</listitem>
<listitem>
<para>
<literal>logical replication launcher</literal>: The background
process that launches logical replication worker processes for
subscriptions.
</para>
</listitem>
<listitem>
<para>
<literal>logical replication parallel worker</literal>: A background
process that applies data modifications on a logical subscriber
for a subscription with <literal>streaming = parallel</literal>.
</para>
</listitem>
<listitem>
<para>
<literal>logical replication sequencesync worker</literal>: A
background process that replicates sequence data on a logical
subscriber.
</para>
</listitem>
<listitem>
<para>
<literal>logical replication tablesync worker</literal>: A
background process that copies table data on a logical subscriber
for a subscription with <literal>copy_data = true</literal>.
</para>
</listitem>
<listitem>
<para>
<literal>parallel worker</literal>: A background process that helps
a backend process to perform operations in parallel.
</para>
</listitem>
<listitem>
<para>
<literal>REPACK decoding worker</literal>: A background process that
decodes WAL for <command>REPACK (CONCURRENTLY)</command>.
</para>
</listitem>
<listitem>
<para>
<literal>slotsync worker</literal>: The background process that
synchronizes logical replication slots on a streaming replication
standby server, active when <xref linkend="guc-sync-replication-slots"/>
is set to <literal>on</literal>.
</para>
</listitem>
<listitem>
<para>
<literal>standalone backend</literal>: The backend process when
<productname>PostgreSQL</productname> was started in
<xref linkend="app-postgres-single-user"/>.
</para>
</listitem>
<listitem>
<para>
<literal>startup</literal>: The background process that replays WAL
during crash recovery, archive recovery or streaming replication.
</para>
</listitem>
<listitem>
<para>
<literal>walreceiver</literal>: The background process that receives
WAL records from a WAL sender, active in streaming replication
standby mode.
</para>
</listitem>
<listitem>
<para>
<literal>walsender</literal>: A background process that sends WAL
records to receivers (during streaming replication) or decodes WAL
and sends the decoded information (during logical replication).
</para>
</listitem>
<listitem>
<para>
<literal>walsummarizer</literal>: The background process that
creates summaries from WAL for use with incremental backup, active
when <xref linkend="guc-summarize-wal"/> is <literal>on</literal>.
</para>
</listitem>
<listitem>
<para>
<literal>walwriter</literal>: The background process that persists
WAL records from WAL buffers to disk.
</para>
</listitem>
</itemizedlist>
In addition, background workers registered by extensions may have
additional types.
</para></entry>