diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 34 | ||||
| -rw-r--r-- | doc/src/sgml/high-availability.sgml | 5 | ||||
| -rw-r--r-- | doc/src/sgml/runtime.sgml | 10 |
3 files changed, 27 insertions, 22 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 7e208a4b812..07b847a8e96 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -697,8 +697,7 @@ include_dir 'conf.d' <para> The default value is three connections. The value must be less - than <varname>max_connections</varname> minus - <xref linkend="guc-max-wal-senders"/>. + than <varname>max_connections</varname>. This parameter can only be set at server start. </para> </listitem> @@ -3495,24 +3494,25 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows </term> <listitem> <para> - Specifies the maximum number of concurrent connections from - standby servers or streaming base backup clients (i.e., the - maximum number of simultaneously running WAL sender - processes). The default is 10. The value 0 means replication is - disabled. WAL sender processes count towards the total number - of connections, so this parameter's value must be less than - <xref linkend="guc-max-connections"/> minus - <xref linkend="guc-superuser-reserved-connections"/>. - Abrupt streaming client disconnection might leave an orphaned - connection slot behind until - a timeout is reached, so this parameter should be set slightly - higher than the maximum number of expected clients so disconnected - clients can immediately reconnect. This parameter can only - be set at server start. - Also, <varname>wal_level</varname> must be set to + Specifies the maximum number of concurrent connections from standby + servers or streaming base backup clients (i.e., the maximum number of + simultaneously running WAL sender processes). The default is + <literal>10</literal>. The value <literal>0</literal> means + replication is disabled. Abrupt streaming client disconnection might + leave an orphaned connection slot behind until a timeout is reached, + so this parameter should be set slightly higher than the maximum + number of expected clients so disconnected clients can immediately + reconnect. This parameter can only be set at server start. Also, + <varname>wal_level</varname> must be set to <literal>replica</literal> or higher to allow connections from standby servers. </para> + + <para> + When running a standby server, you must set this parameter to the + same or higher value than on the master server. Otherwise, queries + will not be allowed in the standby server. + </para> </listitem> </varlistentry> diff --git a/doc/src/sgml/high-availability.sgml b/doc/src/sgml/high-availability.sgml index bbab7395a21..2b4dcd03c87 100644 --- a/doc/src/sgml/high-availability.sgml +++ b/doc/src/sgml/high-availability.sgml @@ -2179,6 +2179,11 @@ LOG: database system is ready to accept read only connections </listitem> <listitem> <para> + <varname>max_wal_senders</varname> + </para> + </listitem> + <listitem> + <para> <varname>max_worker_processes</varname> </para> </listitem> diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 1f78f6c9569..7de26e98ad8 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -720,13 +720,13 @@ psql: could not connect to server: No such file or directory <row> <entry><varname>SEMMNI</varname></entry> <entry>Maximum number of semaphore identifiers (i.e., sets)</entry> - <entry>at least <literal>ceil((max_connections + autovacuum_max_workers + max_worker_processes + 5) / 16)</literal> plus room for other applications</entry> + <entry>at least <literal>ceil((max_connections + autovacuum_max_workers + wax_wal_senders + max_worker_processes + 5) / 16)</literal> plus room for other applications</entry> </row> <row> <entry><varname>SEMMNS</varname></entry> <entry>Maximum number of semaphores system-wide</entry> - <entry><literal>ceil((max_connections + autovacuum_max_workers + max_worker_processes + 5) / 16) * 17</literal> plus room for other applications</entry> + <entry><literal>ceil((max_connections + autovacuum_max_workers + max_wal_senders + max_worker_processes + 5) / 16) * 17</literal> plus room for other applications</entry> </row> <row> @@ -785,13 +785,13 @@ psql: could not connect to server: No such file or directory other applications. The maximum number of semaphores in the system is set by <varname>SEMMNS</varname>, which consequently must be at least as high as <varname>max_connections</varname> plus - <varname>autovacuum_max_workers</varname> plus <varname>max_worker_processes</varname>, - plus one extra for each 16 + <varname>autovacuum_max_workers</varname> plus <varname>max_wal_senders</varname>, + plus <varname>max_worker_processes</varname>, plus one extra for each 16 allowed connections plus workers (see the formula in <xref linkend="sysvipc-parameters"/>). The parameter <varname>SEMMNI</varname> determines the limit on the number of semaphore sets that can exist on the system at one time. Hence this parameter must be at - least <literal>ceil((max_connections + autovacuum_max_workers + max_worker_processes + 5) / 16)</literal>. + least <literal>ceil((max_connections + autovacuum_max_workers + max_wal_senders + max_worker_processes + 5) / 16)</literal>. Lowering the number of allowed connections is a temporary workaround for failures, which are usually confusingly worded <quote>No space |