Connection time-out settings to bypass the operating system time out. | Maximum number of connections that will be allowed to a server from a given plug-in.
Primary and backup servers
Starting with V5, WebSphere Application Server implements a feature called primary and backup servers. When the plugin-cfg.xml is generated, all servers are initially listed under the PrimaryServers tag, which is an ordered list of servers to which the plug-in can send requests.
There is also an optional tag called BackupServers. This is an ordered list of servers to which requests should only be sent if all servers specified in the primary servers list are unavailable.
Within the primary servers, the plug-in routes traffic according to server weight or session affinity. The Web server plug-in does not route requests to any server in the backup server list as long as there are application servers available from the primary server list. When all servers in the primary server list are unavailable, the plug-in will then route traffic to the first available server in the backup server list. If the first server in the backup server list is not available, the request is routed to the next server in the backup server list until no servers are left in the list or until a request is successfully sent and a response received from an application server. Weighted round-robin routing is not performed for the servers in the backup server list.
In WebSphere V6, the primary and backup server lists are only used when the new partition ID logic is not used. In other words, when partition ID comes into play, then primary/backup server logic does not apply any longer. To learn about partition ID, refer to WebSphere Application Server V6 Scalability and Performance Handbook, G24-6392.
You can change a cluster member role (primary or backup) using the administrative console. Select...
Servers | Application servers | <AppServer_Name> | Web server plug-in properties...and select the appropriate value from the Server Role pull-down field.
All application server details in the plugin-cfg.xml file are listed under the ServerCluster tag. This includes the PrimaryServers and BackupServers tags.
... <ServerCluster> ... </Server> <PrimaryServers> <Server Name="wasna01_wasmember01"/> <Server Name="wasna02_wasmember03"/> </PrimaryServers> <BackupServers> <Server Name="wasna01_wasmember02"/> <Server Name="wasna02_wasmember04"/> </BackupServers> </ServerCluster> ...The backup server list is only used when all primary servers are down.