This section explains how to set up database multiplexing mode on the standby server.
In database multiplexing, the files that are required for operations are managed in the Mirroring Controller management directory.
There is one Mirroring Controller management directory for each instance.
Note
Do not place the Mirroring Controller management directory in a directory managed by Fujitsu Enterprise Postgres, otherwise it may be deleted by mistake with the directories managed by Fujitsu Enterprise Postgres, and an old version of files may be restored.
When creating a standby server for a large database, stop job system operations, specify a large value for the wal_keep_size parameter, or use replication slots.
This is because WALs generated after the standby server is built using the pg_basebackup command, but before it is started, need to be retained. However, the number of WAL segments that can be retained is constrained by the wal_keep_size parameter.
Additionally, setting the wal_keep_size parameter requires consideration regarding stabilization of the database multiplexing mode (refer to "2.11.1 Tuning to Stabilize the Database Multiplexing Mode" for details).
See
Refer to "Preparing Directories for Resource Deployment" in the Installation and Setup Guide for Server for details on the directories that are managed by Fujitsu Enterprise Postgres.
Refer to "pg_basebackup" in "Reference" in the PostgreSQL Documentation for information on the pg_basebackup command.
Refer to "mc_ctl" in Reference for information on the command.
Refer to "Appendix A Parameters" for details on each parameter to be edited for the setup.
Refer to "Replication Slots" in the PostgreSQL Documentation for information on replication slots.
Perform the following procedure:
Log in to the standby server.
Create the Mirroring Controller management directory that will store the files required by database multiplexing.
Use ASCII characters in the Mirroring Controller management directory.
Additionally, grant "Write" permission to the instance administrator user for the Mirroring Controller management directory.
Copy, and then deploy, the network.conf file of the primary server.
Copy the network.conf file that was defined in the primary server setup, and deploy it to the Mirroring Controller management directory of the standby server.
Set read and write permissions for the instance administrator user only. If users other than the instance administrator user are granted access, the mc_ctl command will not work. Accordingly, users other than the instance administrator user are prevented from operating Mirroring Controller.
Register in /etc/services the port number of the standby server that was specified in the network.conf file, because programs such as WebAdmin use it to search for available port numbers.
Register any name as the service name.
Copy, and then deploy, the serverIdentifier.conf file of the primary server.
Copy the serverIdentifier.conf file that was defined in the primary server setup, and deploy it to the Mirroring Controller management directory of the standby server.
Set read and write permissions for the instance administrator user only. If users other than the instance administrator user are granted access permissions, the mc_ctl command will not work.
