On Sat, Jul 17, 2021 at 10:45:52AM -0400, Alvaro Herrera wrote: > On 2021-Jul-17, Bharath Rupireddy wrote: > > On Thu, Jul 15, 2021 at 8:17 PM Justin Pryzby wrote: > > > It sounds like something that should be in the glossary, which currently > > > refers > > > to but doesn't define "auxiliary processes". > > > > Thanks. I strongly feel that it should be documented somewhere. I will > > be happy if someone with a clear idea about these various processes > > does it. > > Auxiliary process
I elaborated on your definition and added here. https://commitfest.postgresql.org/34/3285/
>From 9855c0d186251407c868fe0b0d93571541313f55 Mon Sep 17 00:00:00 2001 From: Justin Pryzby <pryz...@telsasoft.com> Date: Sat, 14 Aug 2021 18:51:37 -0500 Subject: [PATCH] glossary definitions for auxiliary processes --- doc/src/sgml/glossary.sgml | 58 ++++++++++++++++++++++++++++++++++---- 1 file changed, 53 insertions(+), 5 deletions(-) diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml index 63ff4bbdf0..881d16d6c4 100644 --- a/doc/src/sgml/glossary.sgml +++ b/doc/src/sgml/glossary.sgml @@ -123,6 +123,27 @@ </glossdef> </glossentry> + <glossentry id="glossary-auxiliary"> + <glossterm>Auxiliary process</glossterm> + <glossdef> + <para> + Process that is in charge of a specific, hardcoded, background task for + an <glossterm linkend="glossary-instance">instance</glossterm>. + The auxiliary processes consist of +<!-- the autovacuum launcher (but not the autovacuum workers), --> + the <glossterm linkend="glossary-background-writer">background writer</glossterm>, + the <glossterm linkend="glossary-checkpointer">checkpointer</glossterm>, + the <glossterm linkend="glossary-stats-collector">statistics collector</glossterm>, + the <glossterm linkend="glossary-logger">logger</glossterm>, + the <glossterm linkend="glossary-startup-process">startup process</glossterm>, + the <glossterm linkend="glossary-wal-archiver">WAL archiver</glossterm>. + the <glossterm linkend="glossary-wal-receiver">WAL receiver</glossterm> + (but not the WAL senders), and the + <glossterm linkend="glossary-wal-writer">WAL writer</glossterm>. + </para> + </glossdef> + </glossentry> + <glossentry id="glossary-backend"> <glossterm>Backend (process)</glossterm> <glossdef> @@ -163,7 +184,7 @@ <glossterm>Background writer (process)</glossterm> <glossdef> <para> - A process that writes dirty + An auxiliary process that writes dirty <glossterm linkend="glossary-data-page">data pages</glossterm> from <glossterm linkend="glossary-shared-memory">shared memory</glossterm> to the file system. It wakes up periodically, but works only for a short @@ -285,7 +306,7 @@ <glossterm>Checkpointer (process)</glossterm> <glossdef> <para> - A specialized process responsible for executing checkpoints. + An auxiliary process that is responsible for executing checkpoints. </para> </glossdef> </glossentry> @@ -881,7 +902,7 @@ <glossterm>Logger (process)</glossterm> <glossdef> <para> - If activated, the process + An auxiliary process which (if enabled) writes information about database events into the current <glossterm linkend="glossary-log-file">log file</glossterm>. When reaching certain time- or @@ -1452,6 +1473,16 @@ </glossdef> </glossentry> + <glossentry id="glossary-startup-process"> + <glossterm>Startup process</glossterm> + <glossdef> + <para> + An auxiliary process that replays WAL during crash recovery and (on + replicas) archive recovery. + </para> + </glossdef> + </glossentry> + <glossentry id="glossary-sql-object"> <glossterm>SQL object</glossterm> <glossdef> @@ -1514,7 +1545,7 @@ <glossterm>Stats collector (process)</glossterm> <glossdef> <para> - This process collects statistical information about the + An auxiliary process that collects statistical information about the <glossterm linkend="glossary-instance">instance</glossterm>'s activities. </para> <para> @@ -1856,7 +1887,8 @@ <glossterm>WAL archiver (process)</glossterm> <glossdef> <para> - A process that saves copies of <glossterm linkend="glossary-wal-file">WAL files</glossterm> + An auxiliary process that saves copies of + <glossterm linkend="glossary-wal-file">WAL files</glossterm> for the purpose of creating backups or keeping <glossterm linkend="glossary-replica">replicas</glossterm> current. </para> @@ -1914,6 +1946,22 @@ </glossdef> </glossentry> + <glossentry id="glossary-wal-receiver"> + <glossterm>WAL receiver</glossterm> + <glossdef> + <para> + An auxiliary process that runs on a + <glossterm linkend="glossary-replica">replica</glossterm> + to receive and replay WAL from the primary server. + </para> + + <para> + For more information, see + <xref linkend="warm-standby"/>. + </para> + </glossdef> + </glossentry> + <glossentry> <glossterm>WAL segment</glossterm> <glosssee otherterm="glossary-wal-file" /> -- 2.17.0