First of all, what is the strategy that you are using for KnowledgeSessions:
1) 1 KnowledgeSession for entire app
2) 1 session per process instance
In the first scenario, if there are multiple process instances running, the session will continue to hold information for the currently running processes and will stay persisted. However, if you use strategy 2, multiple sessioninfo objects will be available based on per process instance. As the instance finishes, it can be safely cleared.
Thank you for your response,
I am using 2 nd strategy (i.e 1 session per process instance) but in SESSIONINFO table data isn't clear.