CICS Internals and Workshop

CICS Internals and Workshop


This course is aimed at:

  • CICS Systems Programmers
  • CICS Application Technical Programmers


Attendees should have had 2/3 years as a CICS Systems Programmer, and ideally should have completed CICS/TS for System Programmers and CICS Transaction Debugging.


4 days. Hands on.

Course Objectives

Upon completion, attendees will be able to describe the internal structure of CICS/TS. All the major Domains will be covered, and the attendee will understand how to analyse the File Control and Enqueue structures. Storage management is covered and the attendee will be able to describe what the causes are of storage violations and how to locate and resolve them. CICS Tracing is covered, as well as a session on using IPCS to analyse the CICS System dumps. A workshop is included and a Storage Violation is created and the attendees will be able to use IPCS to analyze the dump taken. An Enqueue on a VSAM file is also created and IPCS is used to find the Enqueue.

Course Content


Introduction to CICS Architecture
The Domains
The Linkage stacks
The TCB structure
How Tasks migrate to the TCBs
Tasks and Transactions

CICS/TS Domain Structure
The Role of each Domain
• The Kernel
• The Loader
• The Storage Manager
• The Dispatcher
• The Transaction Manager
• The Application
The Gateheaders
The Anchor blocks

The Transaction Manager & Dispatcher Domains
How Transactions are created
How Tasks are created
The role of the Tasentry
The role of the Dispatcher Task Area
The role of the Transaction Manager Transaction block
The role of the Task Control Area
Wait reasons and Wait types
The Executable chain
Interpreting the Transaction Manager Summary Table
Interpreting the Dispatcher Summary Table

The Application Domain
The Common System Area
The Task Control Area
The Exec Interface
File Control
• File Control Block Structure
• Wait reasons
The Application Task Summary Table

The ENQUEUE Domain
How to locate why tasks are waiting on resources
• The NQ Pool
• The NQEA
• How to find out who own the resource and who is waiting


The CICS/TS Storage Management
The Storage Protection facility
The Eight Dynamic Storage Areas
The Transaction Isolation facility
Storage Manager Control Blocks - relationship
• The Storage Manager Anchor block
• The Pagepool Area - PPA
• The Pagepool Extension - PPX
• The Page Allocation Map - PAM
• The Subpool Control Area - SCA
• The Subpool Control Element - SCE
• The Subpool Control Free – SCF
Storage Violations
• Cause of
• How to locate

CICS/TS Recovery Management
How does CICS manage abends
The Kerrrd
• Layout of
The Program Error Program
Application Abend processing
CICS System Abend processing
CICS Transaction dump processing
Using the Dump Utility

CICS/TS Trace Facility
CICS Tracing
• Internal
• Auxiliary
• Generalised Tracing Facility
• How to control the trace
Format of tracing data
• Abbreviated
• Extended
• How to interpret
Printing of Tracing data
• Using the Trace Utility


The IPCS Facility
The Components of IPCS
How to Generate IPCS
• The DDIR
Usage for CICS
How to Invoke
Navigation of the Panels
The Browse facility
The VERBEXIT Commands

Interpreting CICS System Dumps
The Kernel Domain Summary Table
The Dispatcher Domain Summary Table
The Transaction Manager Summary Table
The Application Summary Table
The Kernel Linkage Stacks
The Kerrrd
The Storage Manager Control Blocks
The Loader Domain Summary
The Phase Management Table


Workshops for analyzing a CICS System dump

The first Workshop is to analyse a Storage Violation

The second Workshop is to analyse an Enqueue on a VSAM file

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