Global variables should be unique, and they are specific to IS instances. As you have multiple IS in a cluster, these variables should be identical in all Integration servers that form a cluster.
Using ehcache API also, the scenario is same. When you try to put/get key/value pair in IS, it will be local to that Integration server. You need to make use of distributed cache to share same objects across different clients (IS)
- Terracotta with distributed cache license
HTH
Senthil
#webMethods#Integration-Server-and-ESB