# How to detect on client side that the server side state for the process is closed?

If you are using Ocsigen-start, you probably have nothing to do. Ocsigen-start will monitor the life of sessions and close the process when needed.

If you are not using Ocsigen-start, you must catch exceptions `Eliom_comet.Channel_full`, `Eliom_comet.Channel_closed` (and `Eliom_comet.Process_closed` on Eliom \< 5\). For example, you can use a channel with a different client-process scope to warn client processes that the session is closed. Have a look at module `Os_comet` in Ocsigen-start.