3.3. Deploying Multi-Site/Active-Active Clustering

Note

The procedures in this section are designed for the Multi-Site/Active-Active topology ONLY. Do NOT use these procedures for Composite Active/Active Clustering uing v6 onwards.

For version 6.x onwards, Composite Active/Active Clustering, please refer to Section 3.4, “Deploying Composite Active/Active Clusters”

A Multi-Site/Active-Active topology provides all the benefits of a typical dataservice at a single location, but with the benefit of also replicating the information to another site. The underlying configuration within Tungsten Cluster uses the Tungsten Replicator which enables operation between the two sites.

The configuration is in two separate parts:

  • Tungsten Cluster dataservice that operates the main dataservice service within each site.

  • Tungsten Replicator dataservice that provides replication between the two sites; one to replicate from site1 to site2, and one for site2 to site1.

A sample display of how this operates is provided in Figure 3.3, “Topologies: Multi-Site/Active-Active Clusters”.

Figure 3.3. Topologies: Multi-Site/Active-Active Clusters

Topologies: Multi-Site/Active-Active Clusters

The service can be described as follows:

  • Tungsten Cluster Service: east

    Replicates data between east1, east2 and east3 (not shown).

  • Tungsten Cluster Service: west

    Replicates data between west1, west2 and west3 (not shown).

  • Tungsten Replicator Service: east

    Defines the replication of data within east as a replicator service using Tungsten Replicator. This service reads from all the hosts within the Tungsten Cluster service east and writes to west1, west2, and west3. The service name is the same to ensure that we do not duplicate writes from the clustered service already running.

    Data is read from the east Tungsten Cluster and replicated to the west Tungsten Cluster dataservice. The configuration allows for changes in the Tungsten Cluster dataservice (such as a switch or failover) without upsetting the site-to-site replication.

  • Tungsten Replicator Service: west

    Defines the replication of data within west as a replicator service using Tungsten Replicator. This service reads from all the hosts within the Tungsten Cluster service west and writes to east1, east2, and east3. The service name is the same to ensure that we do not duplicate writes from the clustered service already running.

    Data is read from the west Tungsten Cluster and replicated to the east Tungsten Cluster dataservice. The configuration allows for changes in the Tungsten Cluster dataservice (such as a switch or failover) without upsetting the site-to-site replication.

  • Tungsten Replicator Service: east_west

    Replicates data from East to West, using Tungsten Replicator. This is a service alias that defines the reading from the dataservice (as an trext;) to other servers within the destination cluster.

  • Tungsten Replicator Service: west_east

    Replicates data from West to East, using Tungsten Replicator. This is a service alias that defines the reading from the dataservice (as an trext;) to other servers within the destination cluster.

Requirements.  Recommended releases for Multi-Site/Active-Active deployments are Tungsten Cluster 5.4.x and Tungsten Replicator 5.4.x however this topology can also be installed with the later v6+ releases.