The content for the parameters set in the postgresql.conf file of the primary server is shown in the table below.
Parameter | Value set | Explanation |
|---|---|---|
wal_level | Literal "hot_standby" | Specify the output level for the transaction log. Specify "hot_standby". |
max_wal_senders | Number of standby servers + 1 | Specify the number of standby servers + 1. In Symfoware Server Enterprise Edition and Standard Edition, 1:1 standby is used, so specify 2. |
synchronous_standby_names | 'standbyServerName' | Use single quotation marks (') to enclose the name that will identify the standby server. Any name can be specified. The value specified for this parameter must also be specified in the --standby-names parameter when the mc_ctl command is executed in setup mode. Do not change this parameter while Mirroring Controller is running. |
hot_standby | on | Specify whether queries can be run on the standby server. Specify this to execute reference jobs on the standby server. (*1) |
wal_receiver_status_interval | Time interval (seconds) | This value must be smaller than the value set for replication_timeout in the postgresql.conf file of the primary server. |
wal_keep_segments | Number of file segments | If a delay exceeding the value set in this parameter occurs, the WAL segment required later by the primary server may be deleted. Additionally, if you stop a standby server (for maintenance, for example), consider the stop time and set a value that will not cause the WAL segment to be deleted. Setting this parameter requires consideration regarding stabilization of the database multiplexing mode (refer to "6.9.1 Tuning to Stabilize the Database Multiplexing Mode" for details). Refer to "Estimating Transaction Log Space Requirements" in the Installation and Setup Guide for Server for information on estimating the WAL segment. |
replication_timeout | Timeout (seconds) | Specify the time period after which it is determined that the receiver process (walreceiver) of the transaction log is in an abnormal state. The specified value must be larger than the value set for the wal_receiver_status_interval parameter set in the postgresql.conf file of the standby server. By aligning this value with the value of (heartbeat_interval + heartbeat_timeout) x heartbeat_retry of the serverIdentifier.conf file, you can unify the time after which it is determined that an error has occurred. |
archive_mode | on | Specify the archive log mode. |
archive_command | 'installDir/bin/pgx_xlogcopy.cmd "%p" "backupDataStorageDestinationDirectory/archived_xlog/%f"' | Specify the command and storage destination to save the transaction log. |
backup_destination | Backup data storage destination directory | Specify the name of directory where to store the backup data. Set the permissions so that only the instance administrator user can access the specified directory. Specify the same full path on all servers, so that the backup data of other servers can be used to perform recovery. |
listen_addresses | Standby server IP address, host name, or "*" | Specify the IP address or host name of the standby server. Specify the IP address or host name of the standby server. Specify the IP address or corresponding host name that will be used to connect to the log transfer network. The content specified is also used to allow connections from client applications. To receive the connection and the transaction log from any client or standby server, specify "*". Refer to "Connections and Authentication" in the PostgreSQL Documentation for details. |
max_connections | The limit value for the number of standby server connections + number of simultaneous executions of mc_ctl status (*2) + 2 + number of simultaneous client connections to the instance + superuser_reserved_connections value | Specify the maximum value for the number of standby server connections. The value specified is also used to restrict the number of connections from client applications and the number of connections for the management of instances. Refer to "When an Instance was Created with the initdb Command" in the Installation and Setup Guide for Server, and "Connections and Authentication" in the PostgreSQL Documentation, for details. |
*1: Used in the Mirroring Controller option feature.
*2: Number of simultaneous executions of the mc_ctl command in the status mode.
