diff options
| -rw-r--r-- | doc/src/sgml/config.sgml | 66 | ||||
| -rw-r--r-- | doc/src/sgml/logical-replication.sgml | 86 |
2 files changed, 114 insertions, 38 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index ff6fcd902a8..8e4145979dc 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -4156,7 +4156,13 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows <para> These settings control the behavior of the built-in <firstterm>streaming replication</firstterm> feature (see - <xref linkend="streaming-replication"/>). Servers will be either a + <xref linkend="streaming-replication"/>), and the built-in + <firstterm>logical replication</firstterm> feature (see + <xref linkend="logical-replication"/>). + </para> + + <para> + For <emphasis>streaming replication</emphasis>, servers will be either a primary or a standby server. Primaries can send data, while standbys are always receivers of replicated data. When cascading replication (see <xref linkend="cascading-replication"/>) is used, standby servers @@ -4166,6 +4172,17 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows across the cluster without problems if that is required. </para> + <para> + For <emphasis>logical replication</emphasis>, <firstterm>publishers</firstterm> + (servers that do <link linkend="sql-createpublication"><command>CREATE PUBLICATION</command></link>) + replicate data to <firstterm>subscribers</firstterm> + (servers that do <link linkend="sql-createsubscription"><command>CREATE SUBSCRIPTION</command></link>). + Servers can also be publishers and subscribers at the same time. Note, + the following sections refer to publishers as "senders". For more details + about logical replication configuration settings refer to + <xref linkend="logical-replication-config"/>. + </para> + <sect2 id="runtime-config-replication-sender"> <title>Sending Servers</title> @@ -4213,6 +4230,7 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows <term><varname>max_replication_slots</varname> (<type>integer</type>) <indexterm> <primary><varname>max_replication_slots</varname> configuration parameter</primary> + <secondary>in a sending server</secondary> </indexterm> </term> <listitem> @@ -4229,14 +4247,8 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows </para> <para> - On the subscriber side, specifies how many replication origins (see - <xref linkend="replication-origins"/>) can be tracked simultaneously, - effectively limiting how many logical replication subscriptions can - be created on the server. Setting it to a lower value than the current - number of tracked replication origins (reflected in - <link linkend="view-pg-replication-origin-status">pg_replication_origin_status</link>, - not <link linkend="catalog-pg-replication-origin">pg_replication_origin</link>) - will prevent the server from starting. + Note that this parameter also applies on the subscriber side, but with + a different meaning. </para> </listitem> </varlistentry> @@ -4914,17 +4926,39 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class=" <para> These settings control the behavior of a logical replication subscriber. Their values on the publisher are irrelevant. - </para> - - <para> - Note that <varname>wal_receiver_timeout</varname>, - <varname>wal_receiver_status_interval</varname> and - <varname>wal_retrieve_retry_interval</varname> configuration parameters - affect the logical replication workers as well. + See <xref linkend="logical-replication-config"/> for more details. </para> <variablelist> + <varlistentry id="guc-max-replication-slots-subscriber" xreflabel="max_replication_slots"> + <term><varname>max_replication_slots</varname> (<type>integer</type>) + <indexterm> + <primary><varname>max_replication_slots</varname> configuration parameter</primary> + <secondary>in a subscriber</secondary> + </indexterm> + </term> + <listitem> + <para> + Specifies how many replication origins (see + <xref linkend="replication-origins"/>) can be tracked simultaneously, + effectively limiting how many logical replication subscriptions can + be created on the server. Setting it to a lower value than the current + number of tracked replication origins (reflected in + <link linkend="view-pg-replication-origin-status">pg_replication_origin_status</link>) + will prevent the server from starting. + <literal>max_replication_slots</literal> must be set to at least the + number of subscriptions that will be added to the subscriber, plus some + reserve for table synchronization. + </para> + + <para> + Note that this parameter also applies on a sending server, but with + a different meaning. + </para> + </listitem> + </varlistentry> + <varlistentry id="guc-max-logical-replication-workers" xreflabel="max_logical_replication_workers"> <term><varname>max_logical_replication_workers</varname> (<type>integer</type>) <indexterm> diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml index f8756389a3b..7fdf08b59d0 100644 --- a/doc/src/sgml/logical-replication.sgml +++ b/doc/src/sgml/logical-replication.sgml @@ -1765,31 +1765,73 @@ CONTEXT: processing remote data for replication origin "pg_16395" during "INSER <title>Configuration Settings</title> <para> - Logical replication requires several configuration options to be set. + Logical replication requires several configuration options to be set. Most + options are relevant only on one side of the replication. However, + <varname>max_replication_slots</varname> is used on both the publisher and + the subscriber, but it has a different meaning for each. </para> - <para> - On the publisher side, <varname>wal_level</varname> must be set to - <literal>logical</literal>, and <varname>max_replication_slots</varname> - must be set to at least the number of subscriptions expected to connect, - plus some reserve for table synchronization. And - <varname>max_wal_senders</varname> should be set to at least the same as - <varname>max_replication_slots</varname> plus the number of physical - replicas that are connected at the same time. - </para> + <sect2 id="logical-replication-config-publisher"> + <title>Publishers</title> + + <para> + <link linkend="guc-wal-level"><varname>wal_level</varname></link> must be + set to <literal>logical</literal>. + </para> + + <para> + <link linkend="guc-max-replication-slots"><varname>max_replication_slots</varname></link> + must be set to at least the number of subscriptions expected to connect, + plus some reserve for table synchronization. + </para> + + <para> + <link linkend="guc-max-wal-senders"><varname>max_wal_senders</varname></link> + should be set to at least the same as + <varname>max_replication_slots</varname>, plus the number of physical + replicas that are connected at the same time. + </para> + + </sect2> + + <sect2 id="logical-replication-config-subscriber"> + <title>Subscribers</title> + + <para> + <link linkend="guc-max-replication-slots-subscriber"><varname>max_replication_slots</varname></link> + must be set to at least the number of subscriptions that will be added to + the subscriber, plus some reserve for table synchronization. + </para> + + <para> + <link linkend="guc-max-logical-replication-workers"><varname>max_logical_replication_workers</varname></link> + must be set to at least the number of subscriptions (for apply workers), plus + some reserve for the table synchronization workers. + </para> + + <para> + <link linkend="guc-max-worker-processes"><varname>max_worker_processes</varname></link> + may need to be adjusted to accommodate for replication workers, at least + (<link linkend="guc-max-logical-replication-workers"><varname>max_logical_replication_workers</varname></link> + + <literal>1</literal>). Note, some extensions and parallel queries also + take worker slots from <varname>max_worker_processes</varname>. + </para> + + <para> + <link linkend="guc-max-sync-workers-per-subscription"><varname>max_sync_workers_per_subscription</varname></link> + controls the amount of parallelism of the initial data copy during the + subscription initialization or when new tables are added. + </para> + + <para> + Logical replication workers are also affected by + <link linkend="guc-wal-receiver-timeout"><varname>wal_receiver_timeout</varname></link>, + <link linkend="guc-wal-receiver-status-interval"><varname>wal_receiver_status_interval</varname></link> and + <link linkend="guc-wal-retrieve-retry-interval"><varname>wal_receiver_retry_interval</varname></link>. + </para> + + </sect2> - <para> - <varname>max_replication_slots</varname> must also be set on the subscriber. - It should be set to at least the number of subscriptions that will be added - to the subscriber, plus some reserve for table synchronization. - <varname>max_logical_replication_workers</varname> must be set to at least - the number of subscriptions, again plus some reserve for the table - synchronization. Additionally the <varname>max_worker_processes</varname> - may need to be adjusted to accommodate for replication workers, at least - (<varname>max_logical_replication_workers</varname> - + <literal>1</literal>). Note that some extensions and parallel queries - also take worker slots from <varname>max_worker_processes</varname>. - </para> </sect1> <sect1 id="logical-replication-quick-setup"> |