IBM Transaction Server OS - Manual (Page 5)

Contents
Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
What this book is about . . . . . . . . . . . . . . . . . . . . . ix
Who this book is for. . . . . . . . . . . . . . . . . . . . . . ix
What you need to know to understand this book . . . . . . . . . . . ix
How to use this book . . . . . . . . . . . . . . . . . . . . . ix
Determining if a publication is current . . . . . . . . . . . . . . . ix
Notes on terminology . . . . . . . . . . . . . . . . . . . . . x
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . xi
CICS Transaction Server for OS/390 . . . . . . . . . . . . . . . . xi
CICS books for CICS Transaction Server for OS/390 . . . . . . . . . xi
CICSPlex SM books for CICS Transaction Server for OS/390 . . . . . . xii
Other CICS books . . . . . . . . . . . . . . . . . . . . . . xii
Summary of changes. . . . . . . . . . . . . . . . . . . . . . xiii
Changes for the CICS Transaction Server for OS/390 Release 3 edition . . . xiii
Changes for the CICS Transaction Server for OS/390 Release 2 edition . . . xiii
Changes for the CICS Transaction Server for OS/390 Release 1 edition . . . xiii
Chapter 1. Introducing transaction affinities . . . . . . . . . . . . . 1
The benefits of dynamic routing . . . . . . . . . . . . . . . . . . 3
What does dynamic routing cost?. . . . . . . . . . . . . . . . . 3
Transaction affinities . . . . . . . . . . . . . . . . . . . . . . 3
Inter-transaction affinity . . . . . . . . . . . . . . . . . . . . 4
Transaction-system affinity . . . . . . . . . . . . . . . . . . . 4
Affinity relations . . . . . . . . . . . . . . . . . . . . . . . 4
Affinity lifetimes . . . . . . . . . . . . . . . . . . . . . . . 5
CICS programming techniques for transaction affinity . . . . . . . . . . 5
Safe programming techniques . . . . . . . . . . . . . . . . . . 6
Unsafe programming techniques . . . . . . . . . . . . . . . . . 6
Suspect programming techniques. . . . . . . . . . . . . . . . . 6
Avoiding the effects of transaction affinity . . . . . . . . . . . . . . . 6
Protecting applications from one another . . . . . . . . . . . . . . . 7
Chapter 2. Introducing the Transaction Affinities Utility . . . . . . . . 9
Commands detected by the Transaction Affinities Utility . . . . . . . . . 11
The Scanner component . . . . . . . . . . . . . . . . . . . . . 12
The Detector component . . . . . . . . . . . . . . . . . . . . . 12
What is detected . . . . . . . . . . . . . . . . . . . . . . . 13
What is not detected . . . . . . . . . . . . . . . . . . . . . 14
Controlling the Detector . . . . . . . . . . . . . . . . . . . . 15
How the affinity data is collected . . . . . . . . . . . . . . . . . 15
Saving affinity data . . . . . . . . . . . . . . . . . . . . . . 16
The affinity data VSAM files . . . . . . . . . . . . . . . . . . . 17
The control record VSAM file . . . . . . . . . . . . . . . . . . 17
Detector performance . . . . . . . . . . . . . . . . . . . . . 18
The Reporter component . . . . . . . . . . . . . . . . . . . . . 18
The Builder component . . . . . . . . . . . . . . . . . . . . . 18
Chapter 3. Preparing to use the affinity utility program . . . . . . . . 21
© Copyright IBM Corp. 1994, 1999 iii