Web service session and client restart detection pattern (correct subject)

[am am <ak...@yahoo.com>]

Hi,


I have a web service that needs to keep some kind of session with the web 
clients. 

I.e. a client sends request to the web service, the service makes some internal 
records and can associate the client's requests with the records. Additionally 
the web service makes call backs to the client according to internal events, and 

sends notifications to the client according to the internal records.I.e. server 
acts also as a client.
My problem is, if the client restarts, then these records become stale. This 
means that the client and the server are inconsistent and the client will 
receive notifications based on the stale records.
Is there a standard approach to solve this? I was thinking of sending some kind 
of specific request to the client by the server, in the callbacks, and if I get 
an HTTP 500 I clear the records, but I do not know if this is a good idea.
Can anyone make a suggestion on this please?

Thanks!