question related to cookie

If your VSs are using different pools, then you would run into a problem, because the persistence cookie would hold the value for the specific node, so if your VSs have different pools with different nodes, the persistence cookie make force the request to the wrong node. Because of this, you could either use the default cookie persistence which will create a cookie based on the VS name and be more specific to that VS, or else you may look into something like source address persistence or universal persistence.