You can replicate vPostgres databases to improve reliability, fault tolerance, and accessibility if a database instance fails, or otherwise becomes unavailable.

The vPostgres database within Data Director uses Write-Ahead Logging (WAL) to replicate data between master and slave instances. WAL is a standard approach to transaction logging in which changes to data files are written to only after those changes have been logged. WAL allows for a significant reduction in the number of disk writes because only the log file needs to be flushed to disk at the time of transaction committal, rather than every data file changed by the transaction. Using WAL to replicate data is the fastest type of replication available, allowing you to quickly create slave instances of vPostgres databases.

You can replicate a vPostgres database without any performance penalty to clients accessing the master instance. However, when you failover to a slave instance, all connections to the database are terminated.

Verify that you have provisioned a vPostgres database within Data Director to replicate.

Create slave instances on different datastores assigned to different database groups.

To ensure fault tolerance, replicate slave instances on different datastores than that of the master instance. Create slave instances in different database groups, where each group is assigned to a different resource pool to ensure that slave instances have their own resources with which to operate in the event of a system failure.

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You can replicate a vPostgres database to provide an added degree of fault tolerance and redundancy to your database environment.

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You can manually failover by promoting a slave (or standby) database to take over from its master (or primary) database. When you promote a slave database to take over from its master database, all other slave instances are redirected to use the newly created master instance.