Administration guide > Configure the deployment environment > Configuring catalog and container servers



Best practice: Clustering the catalog service

When you are using the catalog service, a minimum of two catalog servers are required to avoid a single point of failure. Depending on the number of nodes in the environment, you can create different configurations to ensure that at least two catalog servers are always running.


Number of catalog servers

The best practice to avoid a single point of failure for the catalog service domain is to start a minimum of three catalog servers on three different nodes.

If you are using only two nodes, configure two catalog servers on each of the two nodes for a total of four catalog server processes. Creating this configuration ensures that when only one of the nodes is started, the required two catalog servers are running. You must start at least two catalog servers at the same time. When catalog servers start, they look for other catalog servers in the configuration, and do not start successfully until at least one other catalog sever is found.


Example: Starting four catalog servers on two nodes in a stand-alone environment

The following script starts catalog servers cs0 and cs1 on the host1 node, and starts catalog servers cs2 and cs3 on the host2 node.

./startOgServer.sh cs0 -listenerPort 2809 -catalogServiceEndPoints
cs0:host1:6601:6602,cs1:host1:6603:6604,cs2:host2:6601:6602,cs3:host2:6603:6604
-quorum true -jvmArgs -Xmx256m

./startOgServer.sh cs1 -listenerPort 2810 -catalogServiceEndPoints
cs0:host1:6601:6602,cs1:host1:6603:6604,cs2:host2:6601:6602,cs3:host2:6603:6604
-quorum true -jvmArgs -Xmx256m

./startOgServer.sh cs2 -listenerPort 2809 -catalogServiceEndPoints
cs0:host1:6601:6602,cs1:host1:6603:6604,cs2:host2:6601:6602,cs3:host2:6603:6604
-quorum true -jvmArgs -Xmx256m

./startOgServer.sh cs3 -listenerPort 2810 -catalogServiceEndPoints
cs0:host1:6601:6602,cs1:host1:6603:6604,cs2:host2:6601:6602,cs3:host2:6603:6604
-quorum true -jvmArgs -Xmx256m

Remember: You must use the -listenerPort option because the catalog servers that are running on a node each require a unique port number.


Example: Starting multiple catalog servers in a WebSphere Application Server environment

Catalog servers start automatically in a WebSphere Application Server environment. You can define multiple catalog servers to start by creating a catalog service domain. After you specify multiple endpoints in the catalog service domain, restart the included application servers so that the catalog servers start in parallel.


Parent topic:

Configure catalog and container servers


Related tasks

Configure WebSphere eXtreme Scale with WAS

Configure quorum

Configure multi-master replication topologies

Create catalog service domains in WAS

Start and stop servers in a WAS environment

Start a stand-alone catalog service

Start secure servers in a stand-alone environment

Related reference

Server properties file

Catalog service domain administrative tasks