CICS® business transaction services
support client/server processing. These examples show you how BTS
client/server processing works.
A server process is one that is typically waiting for work. When
work arrives, BTS restarts the process, which retrieves any state
data that it has previously saved. Typically, the client invokes the
server with a named input event, and sends it some input data in a
data-container. From these inputs, the server determines what actions
it needs to take. It returns any output for the client in a data-container.
When the client has dealt with any output returned by the server,
it releases the server process. Releasing the server means that its
in-memory instance is freed. The server process is maintained only
by BTS.
Client/server
examples
The client/server examples in this section show:
- A client program initiating a server process and calling it with
some work to do.
- The server defining some input events for which it might be invoked
again; then performing some work and returning output to the client.
- After dealing with the output returned by the server, the client
releasing the in-memory instance of the server.
- The client reacquiring the server process and requesting it to
run again.
- The server process determining the input event that caused it
to be invoked again, and retrieving some state data that it saved
when it last ran; then performing some work and returning output to
the client.
- Eventually, the client telling the server to shut down, and the
server responding to this event by indicating that it must not be
invoked again.