Krishna,
if you are using UM clustering, then your clients should use cluster URLs in the format nsp://sever1:9000,nsp://server2:9000,nsp://server3:9000
You can use comma separator or semi-colon separator between the URLs.
The UM client will automatically handle switching clients to a different server if one should fail.
If you use a semi-colon, you will get similar behavior to the load balancer, but that is not necessarily the most efficient. If your messaging is largely persistent and transactional, and you don’t have very large numbers of subscribers per message, then it is most efficient to have all cliients connected to the master. Follow-the-master is an option in UM 9.9 and higher.
However, even if use of a LB is not recommended, the LB might not be the cause of the problem here. If you are seeing UM servers dying, then you need to investigate the cause. Have you any evidence in log files? Or a heap dump?
You might want to open a support ticket to have the cluster failures looked at.
#Integration-Server-and-ESB#Universal-Messaging-Broker#webMethods