Hello Yong, this is a webMethods tech forum…Terracotta might be owned by SAG but this topic needs to be moved to Terracotta group. Refer to below group.
https://groups.google.com/forum/#!categories/terracotta-oss/tc-server-5x
Having said that, you are in the right direction. You need to have two nodes of TSA Array with active-active setup and a config file with both nodes configured in it. Then you need to use the TSA cache manager instance to establish an application cluster for the Java App. I am pretty sure folks at Terracotta group will be able to help you more. Post you question there!
Cheers,
Akshith
#Integration-Server-and-ESB#webMethods#Flow-and-Java-services