Technical data

4 Configuring WebLogic Servers and Clusters
4-6 Administration Guide
Once the Administration Console has been started, if another process captures the
Listen Port assigned to the Administration Server, you should remove the process that
has captured the server. If you are not able to remove the process that has captured the
Listen Port assigned to the Administration Server, you must edit the
Config.XML file
to change the assigned Listen Port. For information about editing the
Config.XML file,
please see the Configuration Reference.
Planning a Cluster Configuration
When planning a cluster configuration, keep in mind the following constraints on the
networking environment and the cluster configuration.
1. The machine(s) you will be using as WebLogic hosts for the cluster must have
permanently assigned, static IP addresses. You cannot use dynamically-assigned IP
addresses in a clustering environment. If the servers are behind a firewall and the
clients are in front of the firewall, each server must have a public static IP address
that can be reached by the clients.
2. All WebLogic Servers in a cluster must be located on the same local area network
(LAN) and must be reachable via IP multicast.
3. All servers in a cluster must be running the same version of WebLogic Server.
Configure the servers in your cluster to support the particular mix of services that you
are offering.
l For EJBs that are using JDBC connections, all the servers that deploy a
particular EJB must have the same deployment and persistence configuration.
This means configuring the same JDBC connection pool on each server.
l Every machine that hosts servlets must maintain the same list of servlets with
identical ACLs (access control lists).
l If your client application uses JDBC connection pools directly, you must
create identical connection pools (with identical ACLs) on each WebLogic
Server. This means that it must be possible to create any connection pool in
use on all machines in the cluster. If, for example, you configure a pool of
connections to a Microsoft SQL Server database on a Windows NT server
running WebLogic, you cannot use this connection pool in a cluster that