Availability is an essential requirement for most real-time applications. Industries that operate 24x7, such as telecommunications, and global systems that are Web-accessible, such as travel and reservations sites, cannot tolerate service downtime. TimesTen replication enables real-time data replication between in-memory databases for high availability and load sharing. Replication can also be used to facilities online database upgrades and maintenance.

TimesTen replication is supported over LAN and WAN connections. Both Asynchronous and synchronous data replications are available. Asynchronous replication provides maximum performance, but the application is completely decoupled from the receipt process of the replicated elements on the subscriber. For 'pessimistic' applications that need higher levels of confidence that the replicated data is consistent between the master and subscriber databases, synchronous replication with the return receipt or return twosafe services are both supported.

Replication is transaction-log based, this enables high efficiency and low overhead. The replication agent on the master database reads the records from its transaction log and forwards any relevant changes to the agent on the subscriber machine, which then applies the updates to its local database. A range of replication configuration options are supported, including active standby pair with optional read-only subscribers. An active standby pair can be configured for both TimesTen In-Memory Database and In-Memory Database Cache.

Oracle Clusterware is a cluster manager that monitors and controls applications to provide high availability. Clusterware can be used to manage availability for an active standby database, It enables the protection of TimesTen databases and applications within a cluster.

This section describes how you can set up and administer an active standby pair with and without Oracle Clusterware.

TimesTen In-Memory Database

- How to set up and manage an Active Standby Pair on a TimesTen database
- How to set up and manage an Active Standby Pair using Oracle Clusterware on a TimesTen database

In-Memory Database Cache

- How to set up and manage an Active Standby Pair on a cache database
- How to set up and manage an Active Standby Cache Database using Oracle Clusterware on a cache database