To configure a cluster of servers, set up a shared database and file system for the
servers to use.
About this task
To set up servers in a clustered configuration, you install servers on
separate systems and connect the servers to the same database and network storage. Then, you
configure a load balancer to distribute the traffic between the servers. Instead of
accessing the servers directly, users access the load balancer URL. To the users, that URL
appears to host a single instance of the server with high capacity; users are unaware of the
multiple servers.
Note: Servers, agents, and agent relays communicate in two different ways: via HTTP/HTTPS on
the default ports 8080 and 8443 and via JMS on the default ports 7918 and 7916. To set up
the cluster, you must configure the load balancer to distribute the HTTP/HTTPS traffic but
not the JMS traffic. In general, load balancers work well with HTTP/HTTPS traffic because
this traffic is stateless and works on a request and response cycle. By contrast, JMS
connections are long-lived and include a state that is not visible to the load balancer.
Therefore, in general, load balancers are not effective in balancing the JMS traffic and do
not increase performance with respect to this traffic.
To ensure high availability of the
JMS traffic, configure agents and agent relays for failover as described in Configuring agents for failover and Configuring agent relays for failover. In addition, you can also use DNS-level redirection to allow multiple
servers or relays to act as a cluster for redundancy.
Results
After you configure the load balancer to distribute connections to the
systems, users can connect to a single URL and use the entire cluster. The servers also ensure
that the correct number of licenses are used, even if a user accesses multiple
servers.