Users Guide

Planning Clustering | Clustering
OMNM 6.5.3 Installation Guide 119
Config Server Functionality
Clusters’ JMS implementations require ConfigServers. Configuration servers act as the coordinator
for other servers joining the cluster. It must run for other servers to join the cluster. This is true for
either an application server cluster or a mediation server cluster.
When the config server has an error and does not work, depending on the error and how early it
occurs in the startup sequence it may be prevent other servers from joining the cluster.
If a fatal hardware issue occurs with the ConfigServer you can always define another host as the
ConfigServer, making clustering possible, and allowing other cluster members to join.
Planning Clustering
This overview section describes how to configure your cluster setup. See also the Mediation
Clustering
on page 129 for additional advice about high availability mediation servers. For the
initial installation and setup, follow these steps:
1 Plan your server/partition layout.
• Identify the server providing database services.
• Identify the application servers that are members of the cluster.
• Identify the mediation agent(s) that connect to the cluster.
2 Ensure you have a permanent, static IP address for each server that is to be a member of the
cluster.
3 Create your cluster name. You must also assign an IP multicast address to the cluster for
communication between the servers. The IP multicast address must be in the range from
225.0.0.1 - 239.255.255.255. The assignment of the IP multicast should be coordinated
through your system administrator so that conflicts do not occur with other applications. See
Configuring the Cluster’s Multicast Address on page 131.
4 Set up an entry in the DNS with the server name and the IP address for each server to be a
member of the cluster. Minimally, you must map the server name and IP address in the
hosts file. (In Windows this is in C:\Windows\System32\drivers\etc\ , in Linux /
etc/hosts
)
5 Ensure that the Server installation is on each machine that is a member of the cluster. If you
have not installed the application, install it now, using the
Custom installation to configure
various hosts as Application Servers, Mediation Servers, Database Servers, and Web Servers.
CAUTION:
Clustered servers must be on the same subnet. Clustered application servers can, however, be on a
different subnet than clustered mediation servers (which must, themselves, be on the same subnet).