FileStore sessions creates severe message:PersistentManager.swapInInvalid

[adam spline]

I am trying out the Persistent Manager with the FileStore. I frequently get the following message in my log:

org.apache.catalina.session.PersistentManagerBase swapIn
SEVERE: persistentManager.swapInInvalid

This message seems to occur once the sessions have timed out. However, the messages do not appear as a response to a request. It may make sense that a message is displayed if a request has attempted to access an invalid session, which could lead to an invalid swap (why that would be severe I do not know). But in this case, the message seems to appear once the session has timed out.

[1] Why is it even trying to swap in a session if there was no request? Why do that?
[2] Is this message harmless (see this discussion)
[3] If it is harmless how can I suppress this message.

Here is my setup:

<Manager className="org.apache.catalina.session.PersistentManager"   maxIdleBackup="59"  minIdleSwap="30" maxIdleSwap="60">
		<Store className="org.apache.catalina.session.FileStore" directory="sessions" ></Store>
</Manager>

Thanks for your help!

-Adam