Transcript CSKL - CICS Serves, Knowing Legacy is still making most

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 threetiered separation-of-concern approach. Advantages and
drawbacks of short-living TCP connections used in this
approach. Set-up and configuration of the CSKL.
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Agenda
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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?
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GFI-Adelior
[ THE
e- PROCESS COMPANY ]
WELKOM - BIENVENUE WELCOME
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History
Aquisition NAT Systems Withdraw from Europe
COGNICASE (CAN)
1998 1999 2000 2001 2002
NAT SYSTEMS (FR)
EMD
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
Application Engineering
Project Development
Integration into
Adelior
Java / J2EE
adelior benelux
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
1993
2006
ADELIOR (FR)
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2002
2006
GFI
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
e
management...
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NatStar Development
Environment
NCL
Information
Modelling
Process
Modelling
API
Repository
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Builder
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Separation of concern
Application
uses
Communication
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DBMS Services
Data
Services
Application
Services
Presentation
Services
GUI Services
Operating System Services
Generation
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NCL for all Application Objects
Generation of ANSI C code
Specific to target platform
Compilation on required targets
Code
Desktop to Mainframe
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CICS TCP/IP
• Different flavours nowadays
• We use “TCP/IP Socket Interface for CICS”
– “Vanilla” TCP socket programming
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Listener
• CSKL - The Concurrent Server
• Child Servers
CICS
Client
– Take Socket
CSKL
Client
Child servers
Client
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EBCDIC
• Extended Binary-Coded-Digit Interchange
Code
• Code Pages
• Little/Big Endian
• Data Conversion is an issue
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The way to the forum...
zOS
VTAM
CICS
NT
DSNC
CSKL
2 start tran
0 connect
1 trancode
Client application
3 give socket
4 take socket
NSW2COMT
NSCOM.INI
NSSIPTS2
DB2
9 EXEC CICS RETURN
6 EXEC CICS LINK
TCP/IP
stack
5 question
THINGCOM
TCP/IP stack
8 Return
7 Things_Register_Library
10 reply
11 disconnect
Server application library
Libraries
NSW2TCPX
Classes
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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”
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Set-up & Configuration
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EZAC
Define resources (mainly the listener)
Tuning (RTFM!)
Default values are not too bad
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Some resources
• The listener
– CSKL Transaction
– EZACIC02 Program
• Configuration
– EZAC Transaction
• Operation
– EZAO Transaction
• netstat
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Hints & Tips
• Design is ever so important
• Know what to expect both ways
• RTFM!
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The F...ine Manual
z/OS Communications Server
IP CICS Sockets Guide
Version 1 Release 5
Document Number SC31-8807-02
Program Number 5694-A01 and 5655-G52
• That’s in the Communications Server Bookshelf
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Questions
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Questions?
Comments?
Remarks?
Thoughts?
Considerations?
Issues?
Anxieties?
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