Active Standby Pair with In-Memory Database Cache and Clusterware

An Active Standby Pair configuration includes an active database, a standby database, and optional read only subscriber databases. The standby database uses Oracle TimesTen Replication to receive the changes from the active database and forwards the changes to optional read only subscriber databases. The active and standby databases can be either TimesTen In-Memory Database or Oracle In-Memory Database Cache databases.

Oracle Clusterware is a general purpose cluster manager that manages and monitors the availability of software components that participate in a cluster. The TimesTen In-Memory Database is integrated with Oracle Clusterware via the ttCWAdmin utility. When a customer chooses to use Oracle Clusterware with the TimesTen In-Memory Database, the failover and restart of Active Standby Pairs of databases are handled automatically. In addition, Oracle Clusterware may be used to manage the actual applications that use TimesTen.

Install Oracle Clusterware and TimesTen

1.	Install Clusterware	Oracle Clusterware 11.1.0.7 is required.
2.	Install TimesTen	Oracle In-Memory Database Cache 11.2.1 is required.

This example shows how to install Oracle TimesTen and Oracle Clusterware.

Configure an Active Standby Pair for Clusterware and In-Memory Database Cache

1.	Create cache groups	Create some cache groups for the Active Standby Pair. If you have existing cache groups then this step can be skipped.
2.	Detach database from the cache grid	Use the ttGridDetach built-in procedure to detach the database from the cache grid if already attached.
3.	Register cluster information	TimesTen cluster information is stored in the Oracle Cluster Registry. Register the TimesTen cluster information by executing the ttCWAdmin -ocrConfig command on any one of the hosts.
4.	Start cluster agent	Start the TimesTen cluster agent by executing the ttCWAdmin -init command on one of the hosts. This cluster agent will manage the Cache Agent, Replication Agent and TimesTen Main Daemon on all hosts in the cluster.
5.	Create cluster.oracle.ini file	The cluster.oracle.ini config file uses attributes to declaratively define the configuration of an active standby pair that will be managed by Oracle Clusterware. The entry name for the Active Standby Pair in the cluster.oracle.ini file must correspond to the system DSN created in step 1 above.
6.	Create Active Standby Pair	Create an Active Standby Pair by executing the ttCWAdmin -create command on any host in the cluster.
7.	Start Active Standby Pair	Start the Active Standby Pair by executing the ttCWAdmin -start command on any host in the cluster.
8.	Preload data into cache groups	Use the LOAD CACHE GROUP statement to preload the cache groups with data from the Oracle database.

This example shows how to perform the above tasks.

Manage the Active Standby Pair for Clusterware and In-Memory Database Cache

1.	Get cluster status	Find the status of the active standby pair via the ttCWAdmin -status command on any host in the cluster.
2.	Stop Active Standby Pair	Stop the active standby pair via the ttCWAdmin -stop command on any host in the cluster.
3.	Drop Active Standby Pair	Drop the active standby pair via the ttCWAdmin -drop command on any host in the cluster. Always stop and drop the Active Standby Pair before dropping their Cache Group(s).

This example shows how to perform the above common tasks. The following link covers more admin tasks.

Automatic failover and restart for Active Standby Pairs and user applications

The following links describe how Oracle Clusterware is used to failover and restart Active Standby Pairs and user applications.
The following viewlet shows failover and failback of a user application and its corresponding Active Standby Pair and with Oracle Clusterware.