Failover for the distributed session cache

The distributed session cache server is configured in a clustered environment. We can configure up to four master nodes in the cluster to ensure high availability for the distributed session cache.

The primary master of the cluster provides the distributed session cache service to the cluster. If the distributed session cache on the primary master fails, an error is printed in the WebSEAL log. For example:

2013-12-10-12:44:25.525+10:00I----- 0x38CF0B24 webseald ERROR wwa soap 
AMWSOAPHandle.cpp 261 0x7f8cac0ac720 -- 
DPWWA2852E   An error occurred when attempting to communicate 
with the SOAP server URL http://10.150.21.1:2028/DSess/services/DSess: 
HTTPTransportException:Client failed to open Failed to open connection to server:  
--hostname='10.150.21.1' -- service='2028' --  
Error Message='Connection refused'  Error Code='111' --  (error code: 12/0xc).

If there are no supplementary masters specified, the distributed session cache service is unavailable until the primary master is restored. However, if there is a secondary master configured, the distributed session cache fails over to the secondary master. We can also configure tertiary and quaternary masters to provide extra failover for the distributed session cache. For information, search for "Failover in a cluster" in the Administering web reverse proxy topics in the Knowledge Center.

Parent topic: Distributed session cache overview