During peak times, the load on the primary server
may starve the replication process, causing the standby to be several minutes behind.
Although warm standby replication is excellent for automatic database server failover, it
is of no help with client failover. In general, client applications must restart to connect to
the new server after failover. To get around this limitation, warm standby replication can
be complemented with a switching mechanism, which ensures that clients do not need to
reconnect in the event of a failover. With switching technologies, automatic client failover
is transparent to most end-users who see only a slight delay while the switch is made.
In short, warm standby replication (combined with switching) approaches the low data
latency, and seamless server and client failover of a cluster. However its geographic flexibility
makes warm standby replication ideal for disaster recovery after the catastrophic
loss of a data center.
Cold.Standby.
As a low-end strategy for database availability, many companies depend on backup and
restore. After all, the utility programs that come with a database management system as
well as assistant tools have reached a mature stage where they are feature-rich, robust, and
fast.
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