Timesten - Replication (High Availability, Workload distribution)

> Database > (TimesTen|TT) (In-Memory Database|IMDB)

1 - About

TimesTen replication enables to achieve:

  • (near-continuous|High) availability
  • or workload distribution

by replicating transactions between IMDB TimesTen databases.

Type of replication

  • Asynchronous
  • Synchronous Serial
  • Synchronous Parallel

3 - Architecture

A master host is configured to send updates and a subscriber host is configured to receive them.

A host can be both a master and a subscriber in a bidirectional replication scheme.

When replication is configured, a replication agent is started for each database. In the case of multiple database on the same host, each database has a separate replication agent.

Each replication agent can send updates to one or more subscribers and to receive updates from one or more masters. Each of these connections is implemented as a separate thread of execution inside the replication agent process. Replication agents communicate through TCP/IP stream sockets.

For maximum performance, the replication agent detects updates to a database by monitoring the existing transaction log. It sends updates to the subscribers in batches, if possible. Only committed transactions are replicated.

4 - How

4.1 - It detects conflict

Time-based conflict detection and resolution are used to establish precedence in case the same data is updated in multiple locations at the same time.

5 - Configuration

TimesTen recommends the active standby pair configuration for highest availability.

5.1 - Active standby pair

Active standby pair is the only replication configuration that you can use for replicating IMDB Cache.

An active standby pair includes:

  • an active database,
  • a standby database,
  • optional read-only subscriber databases,
  • and the tables and cache groups that comprise the databases.

6 - Documentation / Reference