diff options
| -rw-r--r-- | doc/src/sgml/ref/pg_createsubscriber.sgml | 7 | ||||
| -rw-r--r-- | src/bin/pg_basebackup/pg_createsubscriber.c | 20 |
2 files changed, 26 insertions, 1 deletions
diff --git a/doc/src/sgml/ref/pg_createsubscriber.sgml b/doc/src/sgml/ref/pg_createsubscriber.sgml index 26b8e64a4e0..d56487fe2ca 100644 --- a/doc/src/sgml/ref/pg_createsubscriber.sgml +++ b/doc/src/sgml/ref/pg_createsubscriber.sgml @@ -377,6 +377,13 @@ PostgreSQL documentation server. If the target server has a standby, replication will break and a fresh standby should be created. </para> + + <para> + Replication failures can occur if required WAL files are missing. To prevent + this, the source server must set + <xref linkend="guc-max-slot-wal-keep-size"/> to <literal>-1</literal> to + ensure that required WAL files are not prematurely removed. + </para> </refsect2> <refsect2> diff --git a/src/bin/pg_basebackup/pg_createsubscriber.c b/src/bin/pg_basebackup/pg_createsubscriber.c index 2d881d54f5b..37fdf150b41 100644 --- a/src/bin/pg_basebackup/pg_createsubscriber.c +++ b/src/bin/pg_basebackup/pg_createsubscriber.c @@ -849,6 +849,7 @@ check_publisher(const struct LogicalRepInfo *dbinfo) int max_walsenders; int cur_walsenders; int max_prepared_transactions; + char *max_slot_wal_keep_size; pg_log_info("checking settings on publisher"); @@ -872,6 +873,7 @@ check_publisher(const struct LogicalRepInfo *dbinfo) * - wal_level = logical * - max_replication_slots >= current + number of dbs to be converted * - max_wal_senders >= current + number of dbs to be converted + * - max_slot_wal_keep_size = -1 (to prevent deletion of required WAL files) * ----------------------------------------------------------------------- */ res = PQexec(conn, @@ -880,7 +882,8 @@ check_publisher(const struct LogicalRepInfo *dbinfo) " (SELECT count(*) FROM pg_catalog.pg_replication_slots)," " pg_catalog.current_setting('max_wal_senders')," " (SELECT count(*) FROM pg_catalog.pg_stat_activity WHERE backend_type = 'walsender')," - " pg_catalog.current_setting('max_prepared_transactions')"); + " pg_catalog.current_setting('max_prepared_transactions')," + " pg_catalog.current_setting('max_slot_wal_keep_size')"); if (PQresultStatus(res) != PGRES_TUPLES_OK) { @@ -895,6 +898,7 @@ check_publisher(const struct LogicalRepInfo *dbinfo) max_walsenders = atoi(PQgetvalue(res, 0, 3)); cur_walsenders = atoi(PQgetvalue(res, 0, 4)); max_prepared_transactions = atoi(PQgetvalue(res, 0, 5)); + max_slot_wal_keep_size = pg_strdup(PQgetvalue(res, 0, 6)); PQclear(res); @@ -905,6 +909,8 @@ check_publisher(const struct LogicalRepInfo *dbinfo) pg_log_debug("publisher: current wal senders: %d", cur_walsenders); pg_log_debug("publisher: max_prepared_transactions: %d", max_prepared_transactions); + pg_log_debug("publisher: max_slot_wal_keep_size: %s", + max_slot_wal_keep_size); disconnect_database(conn, false); @@ -939,6 +945,18 @@ check_publisher(const struct LogicalRepInfo *dbinfo) "Prepared transactions will be replicated at COMMIT PREPARED."); } + /* + * Validate 'max_slot_wal_keep_size'. If this parameter is set to a + * non-default value, it may cause replication failures due to required + * WAL files being prematurely removed. + */ + if (dry_run && (strcmp(max_slot_wal_keep_size, "-1") != 0)) + { + pg_log_warning("required WAL could be removed from the publisher"); + pg_log_warning_hint("Set the configuration parameter \"%s\" to -1 to ensure that required WAL files are not prematurely removed.", + "max_slot_wal_keep_size"); + } + pg_free(wal_level); if (failed) |