The new SYBTPSEC parameter called STRTCHK allows recovering and recycling of unused TCP sockets, thus preventing sockets from “hanging” and causing problems with client applications.
The listener handles an incoming request to start an RPC transaction by first starting a handler transaction designated for a gateway or gateway-less mode. In turn, the handler starts the application transaction.
In some situations, the handler transaction will be unable to start, such as when the RACF “APPL” class is being used. CICS provides no way for the listener to detect the non-start of the transaction. However, when activated, the STRTCHK parameter resolves such situations: It specifies a time interval in seconds that the listener can use to compare to the time elapsed since a socket is made available for a new application transaction. If a socket has not been taken in the specified time, the listener recovers the socket, sends an error message, and closes the socket.
Because the STRTCHK feature decreases the efficiency of the listener, it may be left inactive if not needed. A value of -1 (the default) makes the STRTCHK feature inactive.
