© GFI [ THE e -PROCESS COMPANY ] CSKL - CICS Serves, Knowing Legacy (is still making most profit for the organization). How Nat System switched from APPC over SNA to sockets over TCP/IP for the communication between client (Windows application) and server (CICS on z/OS), using the IBM-provided CSKL listener transaction by implementing a "child server" process, thereby leveraging its original three- tiered separation-of-concern approach. Advantages and drawbacks of short-living TCP connections used in this approach. Set-up and configuration of the CSKL.

© GFI [ THE e -PROCESS COMPANY ] Agenda Who am I and where do I come from? NatStar is just as dead as the mainframe ;-) CICS and TCP/IP What did we use it for and how?

© GFI [ THE e -PROCESS COMPANY ] GFI-Adelior [ THE e - PROCESS COMPANY ] WELKOM - BIENVENUE - WELCOME

© GFI [ THE e -PROCESS COMPANY ] History adelior benelux 2006 Java / J2EE GFI EMD NAT SYSTEMS (FR) COGNICASE (CAN) ADELIOR (FR) Aquisition NAT Systems Application EngineeringProject Development Withdraw from Europe Integration into Adelior

© GFI [ THE e -PROCESS COMPANY ] What we do Information systems: designing and building, integration and implementation - the whole system life cycle Manage large and complex projects BPM Technologies: Java, web services, web semantics, Client/Server... Infrastructure services: Linux, Microsoft Business intelligence: BO, Cognos… Application software solutions: accounting, time management...

© GFI [ THE e -PROCESS COMPANY ] NatStar Development Environment InformationModellingProcessModelling GUI Builder Repository API NCL

© GFI [ THE e -PROCESS COMPANY ] Separation of concern Application uses Presentation Services Data Services Application Services GUI Services DBMS Services Operating System Services Communication Services

© GFI [ THE e -PROCESS COMPANY ] Generation NCL for all Application Objects Generation of ANSI C code Specific to target platform Compilation on required targets Code Desktop to Mainframe

© GFI [ THE e -PROCESS COMPANY ] CICS TCP/IP Different flavours nowadays We use TCP/IP Socket Interface for CICS –Vanilla TCP socket programming

© GFI [ THE e -PROCESS COMPANY ] Listener CSKL - The Concurrent Server Child Servers –Take Socket

© GFI [ THE e -PROCESS COMPANY ] EBCDIC Extended Binary-Coded-Digit Interchange Code Code Pages Little/Big Endian Data Conversion is an issue

© GFI [ THE e -PROCESS COMPANY ] The way to the forum...

© GFI [ THE e -PROCESS COMPANY ] Short-living TCP connections +Perfect match for short-living transactions +Eliminates effect of user think-time +Great for automatic fail-over +Server is stateless -Server is stateless -Overhead of connection set-up -TIME_WAIT

© GFI [ THE e -PROCESS COMPANY ] Set-up & Configuration EZAC Define resources (mainly the listener) Tuning (RTFM!) Default values are not too bad

© GFI [ THE e -PROCESS COMPANY ] Some resources The listener –CSKL Transaction –EZACIC02 Program Configuration –EZAC Transaction Operation –EZAO Transaction netstat

© GFI [ THE e -PROCESS COMPANY ] Hints & Tips Design is ever so important Know what to expect both ways RTFM!

© GFI [ THE e -PROCESS COMPANY ] The F...ine Manual Thats in the Communications Server Bookshelf z/OS Communications Server IP CICS Sockets Guide Version 1 Release 5 Document Number SC Program Number 5694-A01 and 5655-G52

© GFI [ THE e -PROCESS COMPANY ] Questions Questions? Comments? Remarks? Thoughts? Considerations? Issues? Anxieties?