The closetimeout parameter specifies the timeout for in-progress requests to complete in milliseconds, when a Client application disconnects from the Gateway daemon.
When a remote Client application disconnects from the CICS® Transaction Gateway, the Gateway daemon might still be processing requests on behalf of that program, if the Client application disconnects before waiting for all outstanding requests to complete.
If the closetimeout parameter is set to zero, when a Client application disconnects, any outstanding work is rolled back and the connection manager and worker threads are returned to the pool. If a time greater than zero is specified, when a Client application disconnects, the Gateway daemon continues to process any outstanding requests for that client for the time specified. When the timeout expires, any outstanding work is rolled back and the connection manager and worker threads are returned to the pool.
This parameter is in the GATEWAY section of the configuration file.