Enabling Master Mirroring
Enabling Master Mirroring
You can configure a new Greenplum Database system with a standby master using gpinitsystem or enable it later using gpinitstandby. This topic assumes you are adding a standby master to an existing system that was initialized without one.
For information about the utilities gpinitsystem and gpinitstandby, see the Greenplum Database Utility Guide.
To add a standby master to an existing system
- Ensure the standby master host is installed and configured: gpadmin system user created, Greenplum Database binaries installed, environment variables set, SSH keys exchanged, and data directory created. Greenplum Database
- Run the gpinitstandby utility on the currently active
primary master host to add a standby master host to your Greenplum Database system. For example:
$ gpinitstandby -s smdw
Where -s specifies the standby master host name.
- To switch operations to a standby master, see Recovering a Failed Master.
You can display the information in the Greenplum Database system view pg_stat_replication. The view lists information about the walsender process that is used for Greenplum Database master mirroring. For example, this command displays the process ID and state of the walsender process:
$ psql dbname -c 'SELECT procpid, state FROM pg_stat_replication;'
For information about the pg_stat_replication system view, see the Greenplum Database Reference Guide.