diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 631f302d7f286c04b115cd61a43930ccdaa0caaf..31ada47b287edd70d511a4bdfddcb2b5ef5174dc 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -2114,12 +2114,16 @@ SET ENABLE_SEQSCAN TO OFF; </indexterm> <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 zero. This parameter can only be set at - server start. <varname>wal_level</> must be set to <literal>archive</> - or <literal>hot_standby</> to allow connections from standby servers. + 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 zero, meaning replication is + disabled. WAL sender processes count towards the total number + of connections, so the parameter cannot be set higher than + <xref linkend="guc-max-connections">. This parameter can only + be set at server start. <varname>wal_level</> must be set + to <literal>archive</> or <literal>hot_standby</> to allow + connections from standby servers. </para> </listitem> </varlistentry> diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 94e22da41e15a92037173ac14e1ead714b039326..3a4cef3448672fa3667968633e7499be4e63784d 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -759,11 +759,16 @@ PostmasterMain(int argc, char *argv[]) /* * Check for invalid combinations of GUC settings. */ - if (ReservedBackends >= MaxBackends) + if (ReservedBackends >= MaxConnections) { write_stderr("%s: superuser_reserved_connections must be less than max_connections\n", progname); ExitPostmaster(1); } + if (max_wal_senders >= MaxConnections) + { + write_stderr("%s: max_wal_senders must be less than max_connections\n", progname); + ExitPostmaster(1); + } if (XLogArchiveMode && wal_level == WAL_LEVEL_MINIMAL) ereport(ERROR, (errmsg("WAL archival (archive_mode=on) requires wal_level \"archive\" or \"hot_standby\"")));