diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/pgupgrade.sgml | 78 |
1 files changed, 76 insertions, 2 deletions
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml index 608193b3070..46e8a0b7467 100644 --- a/doc/src/sgml/ref/pgupgrade.sgml +++ b/doc/src/sgml/ref/pgupgrade.sgml @@ -384,6 +384,79 @@ make prefix=/usr/local/pgsql.new install </step> <step> + <title>Prepare for publisher upgrades</title> + + <para> + <application>pg_upgrade</application> attempts to migrate logical + slots. This helps avoid the need for manually defining the same + logical slots on the new publisher. Migration of logical slots is + only supported when the old cluster is version 17.0 or later. + Logical slots on clusters before version 17.0 will silently be + ignored. + </para> + + <para> + Before you start upgrading the publisher cluster, ensure that the + subscription is temporarily disabled, by executing + <link linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION ... DISABLE</command></link>. + Re-enable the subscription after the upgrade. + </para> + + <para> + There are some prerequisites for <application>pg_upgrade</application> to + be able to upgrade the logical slots. If these are not met an error + will be reported. + </para> + + <itemizedlist> + <listitem> + <para> + The new cluster must have + <link linkend="guc-wal-level"><varname>wal_level</varname></link> as + <literal>logical</literal>. + </para> + </listitem> + <listitem> + <para> + The new cluster must have + <link linkend="guc-max-replication-slots"><varname>max_replication_slots</varname></link> + configured to a value greater than or equal to the number of slots + present in the old cluster. + </para> + </listitem> + <listitem> + <para> + The output plugins referenced by the slots on the old cluster must be + installed in the new PostgreSQL executable directory. + </para> + </listitem> + <listitem> + <para> + The old cluster has replicated all the transactions and logical decoding + messages to subscribers. + </para> + </listitem> + <listitem> + <para> + All slots on the old cluster must be usable, i.e., there are no slots + whose + <link linkend="view-pg-replication-slots">pg_replication_slots</link>.<structfield>conflicting</structfield> + is <literal>true</literal>. + </para> + </listitem> + <listitem> + <para> + The new cluster must not have permanent logical slots, i.e., + there must be no slots where + <link linkend="view-pg-replication-slots">pg_replication_slots</link>.<structfield>temporary</structfield> + is <literal>false</literal>. + </para> + </listitem> + </itemizedlist> + + </step> + + <step> <title>Stop both servers</title> <para> @@ -650,8 +723,9 @@ rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tb Configure the servers for log shipping. (You do not need to run <function>pg_backup_start()</function> and <function>pg_backup_stop()</function> or take a file system backup as the standbys are still synchronized - with the primary.) Replication slots are not copied and must - be recreated. + with the primary.) Only logical slots on the primary are copied to the + new standby, but other slots on the old standby are not copied so must + be recreated manually. </para> </step> |