CloneID (also known as server ID) is appended to the session ID
Once a browser establishes session affinity with an application server, a JsessionId is created. When a HTTP session is created, the session id is passed back to the browser as part of a cookie or URL encoding
The value after : is the cloneID of the server and is used to identify the server. It is usually appended to the JSESSION ID.
This is very useful in a clustered environment for debugging and looking into logs.
This CloneID is only visible from
e.g. location :
search for CloneID