Audience

This course is intended for:

• CICS Systems Programmers
• CICS Application Technical Programmers

Prerequisites

Attendees should have had two or three years as a CICS Systems Programmer, and ideally should have completed CICS for System Programmers.

Duration

4 days. Hands on.

Course Objectives

This CICS INTERNALS course covers up to and including CICS 6.1.

Upon completion, attendees will be able to describe the internal structure of CICS. 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. Attendees will have a CICS 6.1 system for the workshop.

Course Content

DAY 1

Introduction to CICS Architecture

• The Domains
• The Linkage stacks
• The TCB structure
• How Tasks migrate to the TCBs
• Tasks and Transactions

CICS 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 and the Kernel Domain Summary Table
• The role of the Dispatcher Task Area - DTA
• The role of the Transaction Manager block - XMT
• The role of the Task Control Area - TCA
• 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 Domain Summary Table

The ENQUEUE Domain

Enqueues

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

DAY 2

The CICS Storage Management

• The Storage Protection facility
• The 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 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 – DFHDUP/DFHPD

CICS Trace Facility

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

DAY 3

The IPCS Facility

• The Components of IPCS
• How to Generate IPCS
• The DDIR
• The IPCSPRNT
• DFHSNAP
• 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 Domain Summary Table
• The Kernel Linkage Stacks
• The Kerrrd
• The Storage Manager Control Blocks
• The Loader Domain Summary
• The Domain Manager Phase Management Table

DAY 4

Workshop for analyzing a CICS Storage Violation dump

• Attendees will be given a Storage Violation System dump to analyse

Workshop for analyzing a CICS Enqueue Dump

• Attendees will be given an Enqueue System dump to analyse