Warm Standby Applications

A warm standby application is a pair of Adaptive Server databases, one of which is a backup copy of the other.

Client applications update the active database; Replication Server maintains the standby database as a copy of the active database. If the active database fails, or if you need to perform maintenance on the active database or on the data server, a switch to the standby database allows client applications to resume work with little interruption. Warm standby applications topics describe how to set up and configure a warm standby application between two Adaptive Server databases—the active database and the standby database.

See the Replication Server Administration Guide Volume 2 > Manage Warm Standby Applications for detailed information about warm standby applications, how it works in Replication Server, and other related topics.

Most of the times in Replication Server, databases are defined as "primary" and "replicate." However, in discussing warm standby applications databases are also defined as "active" and "standby."

• Warm Standby Application Diagrams
  Learn how a warm standby works. The diagrams illustrate the normal operation, and switching of active and standby databases of an example warm standby application.
• Creating a Logical Connection
  Create a logical connection, which establishes one symbolic name for both the active and standby databases.
• Adding the Active Database to the Replication Server
  Add the active database.
• Marking the Active Database for Replication
  Use sp_reptostandby or sp_setreptable to replicate tables in the active database.
• Adding the Standby Database to the Replication Server
  Add the standby database. The example procedure for configuring warm standby uses a dump of the active database to load the standby database and starts replication after the setup is complete.
• Initializing the Standby Database
  Use Adaptive Server commands and utilities to initialize the standby database.
• Switching the Active and Standby Databases
  Switch from the active to the standby database if the active database will be unavailable for a long time.
• Replicating DDL in a Warm Standby Environment
  Replicate DDL in a warm standby environment.
• Replicating DML in a Warm Standby Environment
  Replicate DML in a warm standby.
• Tracing the Replication Server Transactions to Target Databases
  Trace transactions that Replication Server sends to all replicate databases.
• Replication Definitions for Improving Performance
  A replication definition describes the source table to Replication Server, specifying the columns you want to copy. It may also describe attributes of the destination table. Destination tables that match the specified characteristics can subscribe to the replication definition.
• Using SQL Statement Replication for Warm Standby
  SQL statement replication complements log-based replication and addresses performance degradation caused by batch jobs.