INNOVATION ACCESS METHOD

IAM USER MANUAL VERSION 9.2IAM USER MANUAL VERSION 9.2

INNOVATION DATA PROCESSING is pleased to present the IAM User Manual.

PURPOSE OFTHE GUIDE

This Users Guide outlines the capabilities, describes the basic features of thesecapabilities, and provides directions on their use. It was written primarily for technicalpersonnel who have responsibilities related to the design and implementation ofsystems that will use IAM. This manual is intended to give those personnel a referencethat will help them use IAM as a simple, efficient, reliable alternative to VSAM KSDS,ESDS, and optionally AIX and RRDS processing in batch and online applications.

INNOVATIONDATA

PROCESSING

IAM, IAM/AIX, and IAM/PLEX are proprietary program products of:INNOVATION DATA PROCESSINGInnovation Plaza275 Paterson AvenueLittle Falls, New Jersey 07424-1658

It is available for license exclusively from INNOVATION DATA PROCESSING

Reproduction of this User Manual is prohibited except by licensed users for their internaluse.A copy of this manual is available in Adobe PDF format on the INNOVATION DATAPROCESSING Documentation CD-ROM and on the INNOVATION DATAPROCESSING FTP site for online use and local printing. Copyright 1996, 2013, 2015 INNOVATION DATA PROCESSING

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TABLE OF CONTENTSTABLE OF CONTENTS

1 IAM VERSION 9.2 INTRODUCTION01.00 IAM Version 9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-101.01 Summary of Modifications and Enhancements . . . . . . . . . . . . . . . . . . 1-401.02 Prior Version 9 Summary of Modifications and Enhancements . . . . . . 1-701.03 Organization of This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1201.04 Control Statement Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1401.05 Documentation Notation Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1601.20 Vendor Products That Have Converted VSAM Files to IAM . . . . . . . . 1-1701.21 Vendor Products That Work With IAM . . . . . . . . . . . . . . . . . . . . . . . . . 1-18

2 IAM CONCEPTS AND FACILITIES02.00 IAM Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-102.10 IAM Alternate Index Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-402.20 IAM/PLEX: IAM Sysplex Record Level Sharing . . . . . . . . . . . . . . . . . . 2-602.30 IAM Record Level Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1002.40 IAM's Real Time Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1402.50 IAM Data Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2002.60 IAM Journaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2202.70 SMS Support in IAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2302.80 Automatic DASD Space Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2602.90 Other Features of IAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29

3 IAM DATA SET STRUCTURE03.00 IAM Data Set Structure Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-103.10 Enhanced Format File Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-303.11 Prime Related Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

10 IAM VERSION 9.2 USERS GUIDE10.00 IAM Users Guide Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-110.10 JCL Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-310.20 Defining IAM Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-510.25 Using Hardware Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4610.30 Loading IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5110.40 Processing IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-6010.45 CICS Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7410.50 IAM Tuning Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8510.51 IAM Storage Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-9810.60 Using IAM Alternate Index Support . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10310.61 Defining an IAM Alternate Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10610.62 Building an IAM Alternate Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11710.63 Defining an IAM Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12110.64 Accessing Data Through an IAM Alternate Index . . . . . . . . . . . . . . . . 10-12410.65 Special Considerations with IAM Alternate Indexes . . . . . . . . . . . . . . . 10-12510.70 IAM Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12710.71 IAMPRINT Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12810.72 IAMINFO Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13810.73 IAMSMFVS Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-14710.74 Reporting on IAM Datasets with FDREPORT . . . . . . . . . . . . . . . . . . . 10-15210.75 IAMXMON: IAM Execution Monitor for CICS . . . . . . . . . . . . . . . . . . . . 10-155-iii -

TABLE OF CONTENTS10.80 IAM Dataset Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-15710.81 Reorganizing IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-15810.82 Deleting IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-16910.83 Renaming IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-17110.84 Recataloging IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-17610.85 Backing up and Restoring IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . 10-18110.86 Moving IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-19210.87 Recovering IAM Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-19510.88 IAM Journal and Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-20510.89 Adding Volumes to an IAM Dataset . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-214

20 USING IAM RECORD LEVEL SHARING20.00 IAM Record Level Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-120.02 Multiple IAM/RLS Address Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-720.03 IAM/RLS Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1020.05 Setting up IAM/RLS (Record Level Sharing) . . . . . . . . . . . . . . . . . . . 20-1220.06 IAM/RLS Record Lock Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1620.10 IAM/RLS Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-2020.20 IAM/RLS Automatic Dataset Eligibility . . . . . . . . . . . . . . . . . . . . . . . . . 20-2820.30 IAM/RLS Journaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-3420.40 IAM/RLS Operator Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-4020.41 IAM/RLS Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-4420.50 IAM/RLS CICS Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-4720.60 IAM/RLS Batch Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-5420.70 IAM/RLS Data Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-57

25 USING IAM/PLEX RECORD LEVEL SHARING25.00 IAM/PLEX Record Level Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-125.03 IAM/PLEX Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1025.05 IAM/PLEX JCL Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1225.06 IAM/PLEX Record Lock Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1625.10 IAM/PLEX Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1925.20 IAM/PLEX Automatic Dataset Eligibility . . . . . . . . . . . . . . . . . . . . . . . . 25-2725.30 IAM/PLEX Journaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-3425.40 IAM/PLEX Operator Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-3825.41 IAM/PLEX Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-4225.50 IAM/PLEX CICS Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-4525.60 IAM/PLEX Batch Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-5225.70 IAM/PLEX Data Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-55

30 IAM 9.2 OVERRIDES30.01 IAM Override Statements Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-130.02 IAM CREATE Override Statement Format . . . . . . . . . . . . . . . . . . . . . 30-330.03 IAM ACCESS Override Statement Format . . . . . . . . . . . . . . . . . . . . . 30-1430.04 IAM Override Statement Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-24

40 IAMSMFVS - DATA SET ANALYSIS PROGRAM 40.01 IAMSMFVS - Data Set Analysis Program Overview . . . . . . . . . . . . . . 40-140.02 IAMSMFVS JCL Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-240.03 IAMSMFVS - REPORT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-340.04 IAMSMFVS Usage Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-7-iv -

TABLE OF CONTENTS40.05 IAMSMFVS Summary Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-940.06 IAMSMFVS EXCP Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-1040.07 IAMSMFVS Data Set Summary Report . . . . . . . . . . . . . . . . . . . . . . . 40-1240.08 IAMSMFVS Size Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-14

41 SMF BASIC REPORTING UTILITY 41.01 IAMSMF Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-141.02 IAMSMF JCL Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-241.03 IAMSMF - COPY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-341.04 IAMSMF - IAMINFO Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-741.05 IAMSMF - PRINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-1541.06 IAMSMF - QUERY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-1841.07 IAMSMF - REPORT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-23

45 IAMRECVR IAM DATASET RECOVERY 45.01 IAMRECVR Recovery Program Overview . . . . . . . . . . . . . . . . . . . 45-145.02 IAMRECVR - JCL Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-345.03 IAMRECVR - APPLY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-445.04 IAMRECVR DECOMPRESS Command . . . . . . . . . . . . . . . . . . . . . . 45-745.05 IAMRECVR - DIAGNOSE Command . . . . . . . . . . . . . . . . . . . . . . . . 45-945.06 IAMRECVR IAMSTRUCTURE Command . . . . . . . . . . . . . . . . . . . . 45-1045.07 LIST Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-1145.08 IAMRECVR - PRINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-1245.09 IAMRECVR - RECOVER Command . . . . . . . . . . . . . . . . . . . . . . . . . . 45-14

46 IAMISPF IAMS ISPF INTERFACE 46.01 IAMISPF Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-1

47 IAMJREST - IAM JOURNAL RESTORE PROGRAM47.01 IAMJREST IAM Journal Restore Program Overview . . . . . . . . . . . . 47-147.02 IAMJREST JCL Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-447.03 IAMJREST RESTORE Command . . . . . . . . . . . . . . . . . . . . . . . . . . 47-547.04 IAMJREST Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-947.05 IAMJREST RELEASE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-11

48 IAMJUTIL IAM JOURNAL UTILITY PROGRAM48.01 IAMJUTIL Program Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-148.02 IAMJUTIL JCL Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-248.03 IAMJUTIL COPY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-348.04 IAMJUTIL DUMP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-848.05 IAMJUTIL MVSLOG Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-1348.06 IAMJUTIL SCAN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-15

80 IAM VERSION 9.2 MESSAGES AND CODES80.01 IAM Version 9.2 Messages and Codes . . . . . . . . . . . . . . . . . . . . . . . . 80-180.02 IAM WTO Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-280.03 IAM SYSPRINT Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-3280.04 IAM Journal Exit WTO Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-5480.05 IAM/RLS and IAM/PLEX Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-5780.10 IAM ABEND Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-133-v -

TABLE OF CONTENTS80.20 IAM Catalog Return Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-13580.21 IAM I/O Request Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-13880.22 IAM Open and Close Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-14180.23 COBOL File Status Codes with IAM . . . . . . . . . . . . . . . . . . . . . . . . . . 80-143

90 IAM INSTALLATION INSTRUCTIONS 90.01 IAM Installation Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-190.02 Electronic Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-290.03 CD Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-1990.10 Setting the IAM Global Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-2090.11 Installing the IAM ISPF Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-2590.12 Installing the IAM CICS Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-2790.20 Activating the IAM VSAM Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-3090.30 Testing IAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-4190.31 IAM Installation Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-4490.40 Moving a New Version of IAM into Production . . . . . . . . . . . . . . . . . . . 90-46

91 IAM GLOBAL OPTION CHANGE FACILITY 91.01 IAMZAPOP Overview and JCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91-191.02 IAMZAPOP Format and Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91-391.03 IAMZAPOP ZAP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91-491.04 IAMZAPOP JCL Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91-15-vi -

IAM Version 9.2 Introduction 01.001 IAM VERSION 9.2 INTRODUCTION01.00 IAM Version 9.2 Introduction

What IAM IS IAM is a reliable high performance information storage and retrieval software productthat can be used in place of VSAM data sets for batch, TSO and online processing. IAMoffers a level of performance and reduction in the use of computer system resourcesthat provides substantial savings for most applications that utilize VSAM data sets. IAMreduces CPU utilization, reduces the physical I/O (EXCPs), and offers improvedutilization of DASD space that yields reductions in elapsed time for applicationprocessing.

The IAM product is different from many other VSAM performance enhancementproducts. Rather than trying to tweak VSAM to work faster the IAM approach starts offby using a different underlying file structure and data organization. This innovationcoupled with performance oriented algorithms and coding techniques results insignificant proven performance benefits.

The IAM product is being used to achieve the following benefits:

Reduction of computing costs

Reduction of CPU time

Reduction of EXCPs

Reduction of DASD space utilization

Reduce nightly batch processing window

Delay processor and DASD upgrades

The IAM product is available as a base product that supports KSDS and ESDS type offiles, with two optional feature packages available at extra cost that provide additionalfunctionality. The IAM/AIX feature provides alternate index support and RRDS support.The IAM/PLEX feature provides Sysplex record level sharing support. A free trialversion of IAM is available for users to evaluate the IAM product which includes theIAM/AIX optional feature. If requested it will also include the IAM/PLEX optional feature.

IAM The base IAM product provides a unique set of features and functions to enhance andimprove the performance on VSAM KSDS and VSAM ESDS types of files. These keyfeatures and functions include:

A transparent VSAM interface that requires no changes to application programs,and generally no changes to JCL or CICS regions.

IAM files can easily exceed 4 gigabytes. A single IAM file has a maximum size of54 terabytes. There are no special size considerations for KSDS files. For ESDSfiles to exceed 4 gigabytes, they must be defined with either an 8-byte RBA (IAMXESDS) or with the PSEUDORBA feature of IAM due to the VSAM addressingarchitecture. The current actual size limitation is due to the z/OS DD (TIOT)restriction of a maximum of 59 volumes. For example, on 59 3390-54 volumes,the maximum is 3,186 (54g*59) gigabytes.

IAM data sets are typically allocated as non-VSAM type of datasets, generallyDSORG=PS. IAM datasets can also be defined as Large Sequential datasets(DSNTYPE=LARGE) or as a DFSMS Extended Format datasets to utilize morethan 64K tracks per volume. IAM files can reside on EAV volumes with IAM- 1-1 -

IAM Version 9.2 Introduction 01.00Version 9.0 and z/OS 1.11 or higher as DFSMS Extended Format datasets, andwith z/OS 1.12 as Large Format Sequential or Basic Sequential datasets. IAMfiles that are DSORG=DA should be deleted and redefined to use DSORG=PS.

IAM's automatic Real Time Tuning offers dynamic buffer managementtechniques that are unsurpassed. With the Real Time Tuning TURBO mode, torespond faster to high I/O needs, and increased defaults for the number ofbuffers the need for manual tuning is eliminated for almost all files.

Data Compression facility that can be used for all types of IAM data sets, withless CPU overhead than is typical of VSAM data compression techniques. IAMsupports both an efficient proprietary software data compression technique orhardware compression. Hardware compression can be used with either IAMgenerating a compression dictionary during file load, or with a customizedhardware compression dictionary. Users may be able to achieve even greaterdata compression than can be achieved with standard VSAM hardwarecompression when they opt to build a customized dictionary as described in thismanual. Data compression also helps to reduce physical I/O required to processthe data sets, because more data is contained in a physical block than when it isuncompressed.

Record level sharing within a single z/OS image (LPAR), for concurrentlyexecuting batch jobs, CICS regions and TSO users.

Support for journaling and recovery that offers capabilities normally seen onlywith data base software.

Automatic space release after a file is initially loaded and dynamic secondaryspace adjustments.

Software data compressed files can be reorganized with FDRREORG orIDCAMS without decompressing and recompressing the data. This reducesCPU time and I/O to perform the reorganizations, and it can reduce media usagewhen the sequential copy of the data is placed on DASD.

A Data in Virtual feature called Dynamic Tabling, which keeps those recordsthat are frequently required in a Data Space or in a virtual storage table withinthe users address space.

IAMs run time report IAMINFO, which fully describes each IAM data setprocessed by a job step, along with a complete processing profile, includingresource usage. This data can also be captured by SMF, with reporting availablefrom programs provided with IAM, or customers can write their own SMFanalysis and reporting programs to include the IAM provided data.

IAM provides this unique set of features that are not found in other individualproducts. There are several software packages offered by other vendors that willprovide some of the above functions, but only IAM puts all of this capabilitytogether in one package.

IAM/AIX The IAM/AIX feature is an additional cost feature to the base IAM software product.IAM/AIX uses the full functionality and features described above on IAM base clusterswith IAM alternate indexes and IAM paths and on RRDS types of files. Please note thatall datasets involved in the alternate index sphere must be either all IAM datasets or allVSAM datasets. For example, you cannot have an IAM base cluster with a VSAMalternate index or a VSAM base cluster with an IAM alternate index. It typically onlytakes a few base clusters with alternate indexes for this feature to more than pay foritself.- 1-2 -

IAM Version 9.2 Introduction 01.00IAM/PLEX The IAM/PLEX additional cost feature provides record level sharing support of IAMdatasets across multiple LPARs within a z/OS Sysplex. IAM/PLEX builds upon IAM/RLSby utilizing the XCF Sysplex services and the Sysplex Logger to provide a record levelsharing capability for IAM files within a Sysplex. IAMs implementation is an evolutionarystep forward from the basic single system IAM/RLS that utilizes the IAM/RLS frameworkthat has been in use for several years. The IAM/PLEX design is different fromVSAM/RLS and is intended to enable users to take advantage of record level sharingwithout the complexity involved with setting up a VSAM/RLS environment. IAM/PLEXincludes support for sharing between online (CICS/TS) regions and batch jobs.

IAM Version 9.2Requirements

IAM Version 9.2 utilizes various functions and features only available in z/OSoperating systems and instructions available only on processors that supportz/Architecture. The minimum requirements for IAM Version 9.2 are z/OS operatingsystem and a processor that supports the fifth edtion of z/Architecture Principleof Operations (-04 level) or above. The specific processors are the z/890 and z990and above.

IAM support on systems that do not meet those requirements and are usingz/Architecture machine can use up through Version 9.1. Support is provided forsystems without z/Architecture by IAM Version 8.1.

Due to quad-word alignment required with the 64-bit support, the IAM load libraryrequires and is distributed as a PDSE with a block size of 32760. A normal PDScan be used, but modules will have to be copied to a PDSE should maintenancebe necessary, and then copied back.

Resources Additional information on the IAM product is available on request from Innovation. Thisincludes the following:

White Paper: How IAM Significantly Reduces VSAM Processing Time.

Concepts and Facility Guide

Share Presentation (in Power Point format)

Technical Newsletters- 1-3 -

Summary of Modifications and Enhancements 01.0101.01 Summary of Modifications and EnhancementsIAM Version 9.2 provides a high performance alternative to VSAM for applicationprograms that execute under IBMs z/OS operating system on z/Series processors.Enhancements in IAM Version 9.2 include IAM base product enhancements,enhancements for IAM/AIX, and enhancements for IAM/RLS and IAM/PLEX. Thedetails of these product enhancements are described below.

z/HPF I/O IAM Version 9.2 will utilize z/HPF I/O architecture I/O instructions on IAM Enhancedformat files when the devices and software levels have the functionality necessary forusing the architecture with EXCP level I/O processing. The specific IBM requirementsare as follows:

Software: z/OS 1.12 and z/OS 1.13 with APAR OA38185, or z/OS 2.1 and higher

Processors: z196 GA2, z114, or zEC12 processor and above

Storage: IBM: DS8700 or DS8800 at 6.2 level and aboveHDS: Hitachi Virtual Storage Platform G1000 at microcode level

80-02-01 or higher is appropriate for IAM zHPF support EMC: Customers should contact their local EMC representative

regarding information on an appropriate VMAX microcode level for IAM zHPF support.

IAM's use of z/HPF architecture I/O is automatic when all of the requirements are met.There are a couple of circumstances when z/HPF will not be used which are whenwriting out the DASD EOF block, and when the file extend process needs to format outadditional extended area index blocks. The IAMINFO reports and SMF records includenew statistics that indicate the number of I/O's that were done using z/HPF and thosedone with the standard CCW - ECKD channel programs.

The primary benefit of z/HPF architecture I/O is increased channel capacity. In testingdone at Innovations data center, this is best seen by the reduction in channel connecttime. Our tests have seen an average of 26% reduction in connect time when utilizingz/HPF I/O architecture. A further possible benefit may be some reduction in elapsedtime. Our tests have seen about a 4% reduction in elapsed time when using z/HPF.Because I/O time is only one of many factors in elapsed time, a job may not necessarilyrealize an elapsed time savings.

If an I/O error occurs with a z/HPF I/O, IAM will automatically retry the I/O with standardCCW channel program and temporarily suspend use of z/HPF on that volume for thedataset on which the I/O error occurred.

64-Bit VirtualStorage I/O

Buffers

IAM Version 9.2 can optionally use 64-bit virtual storage for I/O buffers, without anyneed to change application programs. IAM is able to do this because IAM does notever return a pointer to the I/O buffers it is using. Even when locate mode I/O is done,IAM will get a separate storage area and move the record into that area that is in storagethat can be addressed by the application program. The advantage of using 64-bit virtualstorage for buffers are that it will help reduce the demands on 31-bit addressablestorage, and may enable large CICS, IAM/RLS, IAM/PLEX, or other long runningaddress spaces to have more files open concurrently. - 1-4 -

Summary of Modifications and Enhancements 01.01In our testing with 64-bit virtual buffers, it was noticed that there was an increase in CPUtime used, particularly SRB time. With the tools we have available, the increaseappeared to be primarily in page fix processing for 64-bit virtual storage. Because of thepotential impact on CPU time, IAM does not default to using 64-bit virtual storage forbuffers. However, users can set it as the default through the IAM Global Options, or useIAM overrides for the address space(s) where such buffering would be of benefit toeliminate virtual storage constraints.

Enhanced I/OError

Information

I/O errors have occurred where the information provided in the IAMW37 I/O errormessage was insufficient to determine the real cause of the error. To help correct thatdiagnostic information, IAM will now display in the IAMW37 the full 32 bytes of senseinformation available to provide additional information in the rare circumstances that anI/O error does occur.

MessageEnhancements

Users have requested some changes to our messages to facilitate automatedoperations responses to various messages that may occur while processing IAM files.IAM Version 9.2 will now utilize the multi-line WTO function of z/OS so that the datasetthat the message is for can be more easily determined. In general, the IAM messageswill have the dataset name in the last line of the messages issued. Most of themessages will only have two lines, but a few, such as an IAMW37 I/O error messagewith full sense information will require three lines. Additionally, the IAMW22 messagewhich had four different possibilities for recommending an IAM file be reorganized hasbeen changed to one of four separate message numbers which are IAMW21, IAMW22,IAMW91, and IAMW92.

Due to the 70 character per line limit imposed when using the multi-line format of theWTO service, many IAM messages have had there text revised to fit in the reducedamount of space. The changes were done with the intention of keep the messages withas obvious of a meaning as possible with the reduction in the amount of text for many ofthe messages.

Heading lines for many of the reports that IAM produces have been revised to includethe full version level including the SPIN level. Spin levels are full product distributions ofhigher maintenance levels of the IAM Version 9.2 level.

IAM/RLS andIAM/PLEX

IAM Version 9.2 has an additional exit for CICS that along with other internal codingchanges will enable IAM/RLS and IAM/PLEX to handle most of the VSAM RLS only filecontrol options / operands, including UNCOMMITTED, CONSISTENT, REPEATABLE,and NOSUSPEND. CICS application programs that use those functions can now beused without change with IAM/RLS or IAM/PLEX with the full functional support.

IAMSMFVSReport

Enhancements

IAMSMFVS has been enhanced to use 64-bit numbers for various statistics such asEXCP counts may exceed a 32-bit value. Additionally support for SMF interval recordsis now included which enables better reporting for datasets being used by long runningaddress spaces, such as CICS or IAM/RLS without needing the step termination record.One other new feature is the ability for IAMSMFVS to produce a CSV (commaseparated value) for datasets in the VSAM EXCP REPORT to facilitate easy analysiswith a spread sheet.- 1-5 -

Summary of Modifications and Enhancements 01.01Global Options The following are new Global Options in IAM Version 9.2:

BUF64 When enabled indicates that 64-bit virtual storage can be usedfor the I/O buffers for normal file access and update processing. The default isdisabled, meaning that IAM will not use 64-bit virtual buffering.

CRBUFOPT= Has a new optional value of 64BIT that indicates the IAM fileload process is to use two megabytes of 64-bit virtual storage for the I/O buffers.The default value remains the same as prior versions at MCYL.

HPF When enabled Indicates that IAM will use the z/HPF channelarchitecture I/O instructions when the device, processor and z/OS level all havethe support for that function. Default is ENABLED. When disabled, it will meanthat the z/HPF I/O will not be utilized.

IAMW22LIM= Specifies the overflow index storage utilization level that willtrigger the IAMW22 message indicating that a reorganization is recommended.Values are specified in megabytes, which defaults to 64, Valid values range from16 to 1024.

NOMEMLIMIT When enabled will request IAM be permitted to exceed theMEMLIMIT for 64-bit virtual storage for the index subject to an IAM internalmaximum of 64 gigabytes.

The default value for DATASPACE has been increased to 2048 due to some usershaving insufficient data space storage available for loading IAM datasets with a verylarge uncompressed index structure. Other Global Option values remain unchangedfrom the Version 9.1 defaults.

IAM Overrides A change has been made for override processing for CICS, IAM/RLS, and IAM/PLEX.When running in any of those address spaces, the IAM override process willautomatically reread the override statements whenever an IAM file is opened. Thisenables the overrides to be revised without requiring a re-cycle of those addressspaces.

The following are the new or changed overrides for IAM Version 9.2:

BUF64 = YES | NO is a new ACCESS override indicating whether or not IAM isto use 64-bit addressable virtual storage for the I/O buffers. The default is fromthe Global Options Table, which as shipped is set to NO. There are noapplication program changes required to use this capability, as IAM will alwaysmove the data records requested into an area of storage that is addressable bythe application.

CRBUFOPT = 64BIT is a new operand for the CREATE override ofCRBUFOPT. Setting it to 64BIT enables IAMs file load processing to use 64-bitaddressable virtual storage during the file load. The default is taken from theGlobal Options which as distributed is set to MCYL, meaning 31-bit addressablestorage is used.

HPF = YES | NO This is both a CREATE and ACCESS override that will enableor disable use of z/HPF architecture I/O. The override is provided in case thereare any problems or issues using the HPF I/O capabilities. The default is fromthe Global Options which is set to YES as the product is shipped.

NOMEMLIMIT is a new ACCESS override that when specified will allow IAM toexceed the MEMLIMIT if necessary for storage for the index. - 1-6 -

Prior Version 9 Summary of Modifications and Enhancements 01.0201.02 Prior Version 9 Summary of Modifications and EnhancementsIAM Version 9.1 IAM Version 9.1 provides a high performance alternative to VSAM for application

programs that execute under IBMs z/OS operating system on z/Series processors.Enhancements in IAM Version 9.1 include IAM base product enhancements,enhancements for IAM/AIX, and enhancements tor IAM/RLS and IAM/PLEX. Thedetails of these product enhancements are described below.

Uncaptured UCBSupport

IAM Version 9.1 when running under z/OS 1.12 or higher will now be able to utilizeabove the line UCB's without being captured. The UCBs will no longer need to bemoved below the line while the data set is opened, helping to reduce the below the linestorage requirements.

Support forVSAM Editors

When attempting certain functions under ISPF, such as browsing or editing IAM files,ISPF will now always invoke any installation specified VSAM software package such asFile-Aid, File-Manager, Ditto, or other software.

New IAM GlobalOptions

There are a few new Global Options in Version 9.1. The first two area controlled by theENABLE and DISABLE keywords, which are EAV and LARGE. Both of these default todisabled. When the EAV option is enabled it will have all IAM files that are defined afterthe enabling to utilize the extended areas on EAV volumes, in effect setting IAM defaultto EATTR(OPT). When LARGE is enabled it will cause all newly defined IAM files todefault to DSNTYPE=LARGE for Large Sequential Format dataset. Additionally, there isthe CICSTXID Global Option that is used to set the name of the CICS transaction thatwill be invoked for the automatic reconnect when an IAM/PLEX or IAM/RLS addressspace returns to operation.

AutomaticRecatalog forRenamed AIXComponents

When IAM determines that a name of a component in an AIX sphere has been changeddue to a copy process or rename, if IAM determines that there is an identical namechange in the other related components, IAM will now automatically do the definerecatalog that previously would have to be done manually.

ShowcatEnhancement

IAM Version 9.1 enhances the support of the SHOWCAT service when used for IAMfiles to support the RETURN=NAME operand. Users can now obtain names instead ofthe old catalog CI numbers that are effectively tokens. This eliminates the need for thesystem and IAM to maintain internal tables in virtual storage to map the token to thecatalog entry.

PersistentRecord Locks

IAM Version 9.1 enables IAM/PLEX and IAM/RLS address spaces to re-establish recordlocks for recoverable files should the address space terminate, either on request or dueto a failure. This is done through utilization of a new record lock journal file, and the datafrom the system logger or journals. This function enhances data integrity for files utilizingIAM/PLEX or IAM/RLS when an outage occurs. Use of this function is optional.

CICS AutomaticFile Disconnectand Reconnect

Enhancements to the IAM/PLEX and IAM/RLS support for CICS in the event of anIAM/PLEX or IAM/RLS address space termination. When it is detected that such anaddress space is no longer processing, all of the IAM files being processed through thatIAM/PLEX or IAM/RLS address space will be closed. A list will be kept of the files thatwere being used so that they can be re-opened when the address space is active again.When the files are re-opened, any transaction back outs that had been deferred due tounavailability of the IAM files (shunted units of work) will be retried.- 1-7 -

Prior Version 9 Summary of Modifications and Enhancements 01.02AutomaticallyDetermine FileRecoverability

for CICS

IAM will now determine automatically whether an IAM file being opened underIAM/PLEX or IAM/RLS by CICS is a recoverable file and manage the record locks asappropriate to that status. This eliminates the need to set the JRNAD=NONE overridefor files that are not recoverable under CICS.

HiperDispatchEnhancements

Performance enhancements to IAM/PLEX processing for z/OS systems that are utilizingthe HiperDispatch mode. This includes reduction in local lock utilization, use of highperformance Pause and Release function in place of Wait and Post, and changes to I/Otask management and dispatching to minimize the need for the z/OS dispatcher tohandle the I/O requests. This change reduces both SRB and TCB CPU times used byIAM/RLS and IAM/PLEX.

New JournalRecord

A new journal switch record will be written when switching to a journal file to insure thatat least one record has been written out to the new journal. This will prevent anunexpected reuse of the prior journal data set should the IAM/PLEX or IAM/RLS regionbe recycled after the switch but before any new records had been written out to it.

ReplicationLogging

New in IAM Version 9.1 is a replication logging function for IAM/PLEX and IAM/RLS.Referred to as Alternate Logging, this function will write out to a System Logger streamlog records that are compatible with CICS format journal records intended to be used byproducts such as the RRDF Remote Recovery Data Facility from E-Net for datareplication from CICS and batch jobs that are updating IAM datasets under eitherIAM/PLEX or IAM/RLS.

CICS/TS V5.1Support

IAM Version 9.1 is the minimum level of IAM required for use with CICS/TS Version 5.1.

IAM Version 9.0 IAM Version 9.0 provides a high performance alternative to VSAM for applicationprograms that execute under IBMs z/OS operating system on z/Series processors.Enhancements in IAM Version 9.0 include support for EAV super large volumes,increased utilization of 64-bit virtual storage to provide storage constraint relief, andenhancements to IAM Prime Related Overflow feature that can reduce the frequency offile reorganizations for datasets with heavy insert activity. The details of these and otherproduct enhancements are described below.

EAV Support IAM Version 9.0 supports IAM files on Extended Addressable Volumes (EAV). Thisfunction requires z/OS 1.11 or higher. For z/OS 1.11 requires that IAM files must beDFSMS Extended Format to reside on an EAV. For z/OS 1.12 and above the IAMdatasets on EAV volumes can be Large Format Sequential or Basic Format Sequential.EAV eligibility is set by defining the file with a DFSMS Data Class that specifies theEATTR(OPT) attribute, or is defined with the IDCAMS DEFINE parameterEATTR(OPT). IAM files on EAVs cannot be accessed with prior versions of IAM.

Prime RelatedOverflow

Prime Related Overflow (PRO) is an alternative overflow structure within IAM files. ThePRO overflow structure is designed and intended to be used for IAM files that have veryhigh insert activity. For such files PRO provides the benefits of reduced virtual storageusage for the index structure and will reduce the frequency of reorganizations. The PROsupport has been revised and enhanced in Version 9.0. PRO files created with Version9.0 are not downward compatible with prior IAM releases. - 1-8 -

Prior Version 9 Summary of Modifications and Enhancements 01.0264-bit VirtualStorage

IAM Version 9.0 can use z/OS 64-bit addressable virtual storage to hold the index foropened IAM files. All of the code involved in the processing of the index for IAM files hasbeen converted to utilize the z/Architecture 64-bit instructions. Use of this functionprovides virtual storage constraint relief and eliminates the two gigabyte limitation for theindexes to IAM files. Depending on installation default values, users may need to usethe MEMLIMIT JCL parameter on job steps that they desire to use this capability.

XTIOT & 31-bitDSAB Support

IAM Version 9.0 supports IAM files existing in the XTIOT (above the line TIOT area) and31-bit DSAB control blocks. This support will allow users to allocate more datasets totheir CICS, IAM/RLS, and IAM/PLEX address spaces. The XTIOT support currentlyexcludes IAM files that are DFSMS Extended Format. This support requires that onlyIAM Version 9.0 or higher is active on a system, otherwise code from prior version willprevent the use of the XTIOT and 31-bit DSABs for IAM files.

Alter Capability Through the DEFINE RECATALOG process and the applicable IAM CREATEoverrides, various attributes of IAM files can now be altered. The information that can bechanged are values for buffer space, journaling, maximum buffers, minimum buffers, theRLSID, and the share options. - 1-9 -

Prior Version 9 Summary of Modifications and Enhancements 01.02Global OptionChanges

Some of the default values of the IAM Global Options have changed in Version 9.0 togenerally recommended values. Two of the Global Options are new for Version 9.0, asindicated by an asterisk next to the option. For the new options, the Version 8.1 valueshown in parenthesis represents the effective value. The table below indicates theGlobal Option, the new default value for Version 9.0, and the default value in Version8.1:

Figure 1-1: Table 1: New and Changed Global Options

IAM LoadLibrary

Due to quad-word alignment with the 64-bit support, the IAM load library requires and isdistributed with a block size of 32760. In order to apply maintenance to some of loadmodules, it also must be a PDSE. A normal PDS can be used, but modules will have tobe copied to a PDSE should maintenance be necessary, and then copied back.

Error MessageEnhancements

To aid with problem diagnosis, most error messages will now have a second linecontaining the affected dataset name. Additionally IAM now supports the ACB messagearea, passing back open error messages if an open fails for an IAM file to the applicationprogram, in addition to writing the message to the job log.

IAM/RLS Based on user input, a number of modifications have been made to IAM/RLS that aresummarized as follows:

There will be one dataset name table that is applicable to all of the IAM/PLEX andIAM/RLS address spaces within a Sysplex. This provides one central location to controlthe use of IAM record level sharing capabilities. To facilitate a single table, a newparameter of RLSID=nnnn is added on the SELECT and EXCLUDE statements toindicate which IAM/RLS or IAM/PLEX address space can select or exclude the datasetsfrom processing. Additionally, an enhanced dataset name masking capability isprovided for the specification of dataset names on the SELECT and EXCLUDEstatements. This will help to reduce the size of the table as it exists both in source formatand in internal format that is kept in virtual storage.

64-bit addressable virtual storage can now be used to contain the record locks withineach IAM/RLS and IAM/PLEX address space. This capability will increase the numberof record locks that can be held, and reduce contention for 31-bit addressable storage.This is enabled by specification of the LOCKMEM=64BIT IAM/RLS and IAM/PLEXstartup parameter. Use of this capability will generally require users to specify theMEMLIMIT keyword on the EXEC card for the IAM/RLS or IAM/PLEX JCL procedures.

An automatic sync point process is now available for batch jobs. This will be controlledby a new ACCESS override of AUTOSYNCPOINT=nnnnn which specifies that a syncpoint will be taken after the specified number of lock obtaining requests have beenissued.

Global Option Version 9.0 Version 8.1 BELOWPOOL YES NODATASPACE 1024 256ESDSLOCK* ENABLED (enabled)INDEXSPACE 64BIT CICSLONGKEYS 33 128XESDS* DISABLED (disabled)- 1-10 -

Prior Version 9 Summary of Modifications and Enhancements 01.02RLSINFO, a new statistical report, can be automatically produced on a periodic basis forboth IAM/RLS and IAM/PLEX address spaces. Similar to the IAMINFO report, thesereports provide information on the activity that has occurred within the particularIAM/RLS or IAM/PLEX address space. This report is enabled by the STATS=ON startupparameter, and the specification of an RLSINFO DD card in the proc used to startIAM/RLS or IAM/PLEX.

Various error messages for a dataset, particularly for open failures, are passed back tothe program that issued the open in the ACB message area, and are also displayed onthe job log. This is to help diagnose problems reducing the need to examine theRLSLOGDD or the job log of the IAM address space to find error messages.

A number of internal processing changes were made that are intended to helpperformance for IAM/RLS and IAM/PLEX processing and to reduce some of the CPUtime used. Included in the changes is a reduction in use of the local lock for serialization.This has included the reducing or elimination of use of various system services, alongwith implementation of different serialization techniques to reduce the resourcecontention.

IAM/PLEX IAM Version 9.0 presents IAM/PLEX, a z/OS SYSPLEX record level sharing capabilityfor VSAM applications that is available as an additional cost feature of the IAM product.This feature enables VSAM applications to execute concurrently and update IAM fileson multiple LPARs / systems that are part of a z/OS Sysplex. The applications sharingthese files can be any mix of CICS/TS transactions, batch programs, or TSOapplications. The IAM/PLEX approach to Sysplex record level sharing of datasets isintended to provide users with record level sharing capabilities without theimplementation complexity and application changes that are typically necessary forimplementing VSAM record level sharing. The IAM/PLEX function utilizes the z/OSSysplex XCF services, the z/OS System Logger facilities, and the IAM/RLS frameworkto enable the sharing of datasets at the record level across multiple LPARs.

Details on IAM/PLEX are in Section 2.20 and Section 25 of the IAM Manual.- 1-11 -

Organization of This Manual 01.0301.03 Organization of This ManualFormat of the

ManualThe IAM manual is divided into sections, by a major general topic, identified by aninteger such as 10 or 20. Sections are divided into subsections by subtopic, withidentifiers such as 10.20 or 30.02. Within subsections, subtitles may appear in the leftmargins to help you quickly find topics of interest. Each page displays its subsection titlein the top center of the page, and the subsection number at the top right corner. Withineach section, pages are numbered with the section number and a sequential pagenumber within the section, e.g., page 80-12.

As much as possible the section numbers used in prior versions of the manual remainthe same in the IAM Version 9.0 manual. The main change in the organization of theIAM Version 9.0 manual is that section 00 from prior versions has now been merged intosection 01 and a new section 25 has been added for the IAM/PLEX feature. Thebenchmark data that was in Section 00.02 of the IAM V8.1 manual has been removedfrom the manual, and will be available in an updated version of the IAM White Paper.

Contents of theManual

The IAM manual contains documentation and instructions for utilizing the IAM productincluding the optional features IAM/AIX and IAM/PLEX. Therefore portions of themanual may not be relevant if you are not licensed for the feature being discussed.Documentation regarding the older IAM compatible format files has been removed fromthe IAM Version 9.2 Manual, but remains available in prior manual versions, such as inthe IAM Version 8.1 Manual. IAM Version 9.2 does still support compatible format fileshowever it has been functionally stabilized for over ten years, and does not provideaccess to all the features and functions of IAM.

All users are encouraged to utilize the standard IAM Enhanced file format.Users whohave the FDREPORT product can use that to find all of their compatible format files.Below is an example of the JCL and control statements to do so:

Figure 1-2: Figure 1: Example JCL to use FDREPORT to find Compatible Format files (EX0103A)

//IAMFILES EXEC PGM=FDREPORT,REGION=0M//SYSPRINT DD SYSOUT=*//ABRMAP DD SYSOUT=*//SYSIN DD * XSELECT DSORG=IAM XEXCLUDE IAMINDIC=ENHANCED REPORT FIELDS=(DSN,VOL,SIZE,NOEXTENT,IAMINDIC,DATES) TITLE LINE='IAM COMPATIBLE FORMAT FILES' SUMMARY FIELDS=(DSN) PRINT ENABLE=IAM,SORT=COMBINE, SORTALLOC=(SORTWORK,CYL), ONLINE,SUM=YES/*- 1-12 -

Organization of This Manual 01.03Improving theManual

We have tried to make this manual as complete, precise and error free as possible.However, in spite of our best efforts, errors and incomplete explanations may have creptin. Should you encounter any of these, we would appreciate your corrective criticism. Itis primarily through your feedback that we can improve this manual. There is a Reader'sComment Form at the back of the manual; you may mail it, fax it, or send us e-mail.

Examples All examples and Job Control Language statements shown in this manual are forILLUSTRATIVE PURPOSES ONLY! You must modify them to meet the JCLrequirements of your installation.

The JCL examples in this manual are also included in a JCL library on the distributionmedia If you load this JCL library to disk, you can reduce the time required to setup jobsfor various IAM functions by using the JCL library members as a starting place. - 1-13 -

Control Statement Format 01.0401.04 Control Statement FormatGeneral The IAM control statements consist of 80-character logical records. The general format

of these records is:

Figure 1-3: Figure 2: General Control Statement Format

Command Field The command field identifies the control statement and consists of a one or morecharacter command word. It may appear anywhere within columns 1 to 71 and can onlybe preceded by blanks. The command word must appear in its entirety within columns 1to 71; it may not be continued.

Operand Field The operand field, if present, follows the command field and is separated from it by atleast one blank. The operand field consists of one or more keywords and/or positionalparameters, separated by commas. It may not contain embedded blanks except withinquoted strings. Operand fields may be continued onto subsequent logical records. Ifoperands are to be used with a command, at least one operand must be on the logicalrecord containing the command.

Comments Field The comments field, if present, follows the operand field(s) and is separated by one ormore blanks. It may contain any information deemed helpful by the person who codesthe control statement. Comments fields may not be continued, i.e., they must end at orbefore column 71. Comments are not permitted on a control statement that allowsoperands but on which no operands have been specified.

Coding anOperand Field

An operand field consists of one or more positional or keyword parameters separated bycommas.

PositionalParameters

Positional parameters must be coded in a specific order relative to one another. Thismeans that the variable data you substitute for positional parameter 1 must precede thevariable data for positional parameter 2, and so on. The absence of variable data to besubstituted for a positional parameter is indicated by coding a comma in its place.However, you may omit the commas when the absent parameter is the last one, or if allfollowing positional parameters are absent.

Column Column Column 1 72 80---------------------------------------------------------------------- | | | | | | COMMAND OPERANDS COMMENTS | | | | | | | | |

WHERE:

Columns 1 to 71 - contain the command, operands, and comments fields, except when continued to subsequent logical records.

Column 72 - must be blank if the command or operands extend to column 71.

Columns 73 to 80 - not used by IAM. We suggest you use them as an identification or sequence field. - 1-14 -

Control Statement Format 01.04KeywordParameters

Keyword parameters are position independent, and consist of either a keyword alone ora keyword followed by an equal sign (=) followed by user-specified variable information.When both positional and keyword parameters are to be coded in an operand, keywordparameters must precede positional parameters.

Sub-parameters Both positional and keyword parameters may consist of a list of subparameters. Such alist is composed of positional parameters that follow the usual rules for that type. Asubparameter list must be enclosed within parentheses, unless the list reduces to asingle subparameter, in which case the parentheses may be omitted.

Quoted Strings When the variable data you specify for a parameter contains certain special characters,defined below, you must enclose the data with apostrophes. This is called a 'quotedstring'. Within a quoted string, all characters, including blanks, may appear; if anapostrophe is to be part of the string, it must be coded as two apostrophes.

NOTE: Special characters are parentheses, commas, equal signs, apostrophes, andblanks.

Continuing anOperand Field

When the total length of an operand field exceeds the available columns in a logicalrecord, it must be continued onto one or more following logical records. To continue anoperand, interrupt the operand field after a complete parameter or subparameter,including the following comma. Do this at or before column 71. Leave the next columnblank.

Continue the operand field starting anywhere between columns 1-71 on the followinglogical record.

Any number of logical record continuations may be present.

ExampleContinuedStatement

Figure 1-4: Figure 3: Example of a Continued Control Statement

CommentStatement

If you really have a lot to say, you may code a comment statement, which are controlstatements with nothing but remarks contained within columns 2 to 71. Commentstatements are identified by an asterisk (*) in column 1. They may appear anywherewithin a group of control statements, even between continued logical records.

REPORT MAXDSNS=6000, EXAMPLE OF A DETAIL, CONTINUED OPERAND

GROUPNAMES=(CICS,ABC), FIELD, WITH MAXREPORTS=5000 COMMENTS- 1-15 -

Control Statement Format 01.0501.05 Documentation Notation FormatNotation The following notation is used in this manual to define control statement formats:

Uppercase letters and words must be coded exactly as shown in a format description.

Lowercase letters and words represent variables for which you must substitutespecific information.

Brackets are never coded. They indicate that the enclosed item is optional, and youcancode one or none of the items.

For Example: [,MAXDSNS=nnnn ]

An ellipsis . . . (3 consecutive periods) is never coded. It indicates that the precedingitem can be coded more than once.

For Example: DSN=(dsname,dsname . . . )

An underscore ______ is never coded. It indicates that the underscored item is theabbreviation for the value.

For Example: DATACOMPRESS= YES | NO

A vertical bar | is never coded. It indicates that there is a choice between the valuesspecified.

- 1-16 -

Vendor Products That Have Converted VSAM Files to IAM 01.2001.20 Vendor Products That Have Converted VSAM Files to IAMThis is a sample of some of the Vendors' products that Customers have converted VSAM files to use IAM:

VENDOR PRODUCT

Accero (CYBORG) Payroll

American Software DRP

ASG (Mobius) ViewDirect

Atos Origin CARDLINK

CGI CGI Advantage

CSC Hogan. Cyberlife, Capsil

CSI Bank Trade

Fidelity National Systematics Banking Appl, BASE2000, CSF

First Data VisionPLUS

Fiserv Pep Plus, Mortgage-Serv

Infor (GEAC) GL, AR, MSA, Millennium, Walker, Infopoint Deposits

JDA Compass Contract

LRS PageCenter

LSI Popims

Mackinney Software JES Queue Print

McKesson (HBO) HealthQuest

Pitney Bowes (Group 1) Finalist, Code 1, Mailstream Plus

Retalix (NCR) Biceps, ABS

SEA TRMS, SAVRS

Serena Changeman ZMF

Shaw Systems Collections

Siemens Medical Systems Invision, Signature

Sigma SAM (Student Aid Management)

SunGuard (SCT) SIS+, HRS, FRS

Empower Software (Tesseract) Payroll, HR, Benefits

TriZetto ClaimFacts, GroupFacts

VIPS Medicare Part B, SuperOP- 1-17 -

Vendor Products That Work With IAM 01.2101.21 Vendor Products That Work With IAMIAM works with many system management software products that are used with VSAMtoday. Below is a list of products known to work with IAM. In many circumstances, thesevendors have made enhancements to their products so that they can be used with IAMfiles. This is by no means a complete list of all the products that do work with IAM files.

DASD MANAGEMENT SOFTWARE:

FDR/ABR (INNOVATION DATA PROCESSING) FDRREPORT (INNOVATION DATA PROCESSING) FDRREORG (INNOVATION DATA PROCESSING) DF/SMS (IBM) DF/HSM (IBM) DF/DSS (IBM) CA ALLOCATE (formerly VAM) (CA) DMS/OS (CA) POOLDASD (BOOLE & BABBAGE) MAINVIEW SRM STOPX37/II (BMC)

JOURNALING AND RECOVERY:

FILE SAVE (CA) DRS (BMC) AR/CTL (BMC) CICS/VR (IBM) RRDF - Remote Recovery Data Facility (E-Net)

MISCELLANEOUS PRODUCTS:

FILE-AID (COMPUWARE) ABEND-AID (COMPUWARE) CICS (IBM) CONNECT: DIRECT (IBM-Sterling) ISPF (IBM) NETWORK DATA MOVER (CA) (NDM) SELCOPY and SELCOPY/i (CBL Compute (Bridgend) Ltd) SHRINK (CA)

PERFORMANCE MONITORS:

OMEGAMON (TIVOLI) THE MONITOR TMON (ASG) STROBE (COMPUWARE)

PROGRAMMING LANGUAGES:

VS/COBOL (IBM) COBOL II (IBM) FORTRAN (IBM) PL/1 (IBM) BAL (IBM) CA/OPTIMIZER (CA) SAS (SAS INSTITUTE)- 1-18 -

Vendor Products That Work With IAM 01.21 SECURITY PRODUCTS:

RACF (IBM) ACF/2 (CA) TOPSECRET (CA)

SHARING PACKAGES:

IAM/PLEX (IDP) SHARE OPTION 5 (CA) SYSB (H & W)

SORT PRODUCTS:

SYNCSORT (SYNCSORT) DF/SORT (IBM) CA/SORT (CA)- 1-19 -

THIS PAGE INTENTIONALLY LEFT BLANK- 1-20 -

IAM Overview 02.002 IAM CONCEPTS AND FACILITIES02.00 IAM Overview

IAM Basics IAM is a high performance indexed access method for z/OS that offers numerousadvantages over the IBM provided VSAM access method. IAM files exist on DASD in adifferent file structure than VSAM datasets, with IAM providing a VSAM compatible API(Application Programming Interface) for KSDS and ESDS file types. IAM/AIX availableas an additional cost feature provides support for alternate indexes and RRDS file types.Existing as non-VSAM data sets provides IAM with capabilities to eliminate the 4.3-gigabyte file size restriction in VSAM for files that are not DFSMS Extended Format withExtended Addressability, and to choose a block size that will optimize space utilizationon each of the different type of DASD devices and architectures available. Along withIAM's unique file structure, described in a subsequent section and IAM's DataCompression feature, user data stored in an IAM file typically requires substantially lessDASD space then when stored in a VSAM cluster.

The basic principle of IAM is to intelligently utilize virtual storage to reduce the need toperform physical I/O to look up and retrieve data. This is accomplished by using thesophisticated IAM Real Time Tuning concept to manage buffers, and by keeping theindex for files in virtual storage while they are being processed. IAM requires at mostone I/O to retrieve any explicitly identified record within the IAM data set. All of the indexI/O's and index buffers used by VSAM are eliminated.

Dynamic FileExpansion

IAM files can acquire additional DASD extents as necessary subject to the type ofdataset that is being used. IAM supports basic non-VSAM file structure, the largesequential dataset structure, the SMS sequential extended format, and SMS sequentialextended format on EAV volumes. In all cases files are limited to a maximum of 59volumes.

Figure 2-1: Table 2: DSN Type Specifications

DSNTYPE Extents per volumeMAX

ExtentsMAX Space per

Volume

BASIC 16 255 64K TracksLARGE 16 944 64K CylindersLARGE FORMAT + EAV (z/OS 1.12 and above)

16 944 >64K Cylinders

EXTENDED FORMAT 123 7,257 64K CylindersEXTENDED FORMAT + EAV(z/os 1.11 and above)

123 7,257 >64K Cylinders- 2-1 -

IAM Overview 02.00Maximum FileSize

The maximum size of an IAM file within the internal file architecture is 128 terabytes.Given the combination of the IAM software implementation and the 3390 trackarchitecture, assuming a track blocking factor yields a maximum of 54 terabytes.

In real world terms, the maximum size is subject to the 3390 track architecture and thelimits indicated in the table shown above. The current major factor beyond actualvolume size is the limit of 59 volumes per dataset. Given that consideration, themaximum size of an IAM file on all 3390-54 size volumes, assuming either large formator extended format, is approximately 3,186 gigabytes of compressed data. On all EAVvolumes with the current maximum of approximately 223 gigabytes per EAV volume,that yields a maximum IAM file size of 12.8 terabytes. For a basic non-VSAM format file,the limit is 201 gigabytes of compressed user data due to the 64K tracks per volumemaximum.

The above size limitation applies to IAM KSDS file types, RRDS file types, and to IAMESDS file types defined with the XESDS attribute. For applications that require a true 4-byte VSAM RBA value for an ESDS file the size limitation is 4 gigabytes of user data.

VSAMTransparency

IAM's system level VSAM Interface provides application program transparency. IAMallows an unaltered application program executing under z/OS to access IAM files inplace of VSAM KSDS, ESDS, RRDS, and AIX files. IAM can be used in conjunction withthe common programming languages COBOL, BAL (assembler), PL/1, RPG, C and anyhigher-level language products, which support keyed access to VSAM files.

IAM supports programs executing in AMODE(31) and VSAM control blocks (ex: ACB,RPL) residing above the 16MB line.

IAM supports the full range of VSAM file access commands GET, PUT, INSERT,GETPREV, ERASE, POINT, etc. and the file status commands SHOWCB, TESTCB,GENCB, and the VSAM catalog lookup macro, SHOWCAT.

IAM supports the following functions of IDCAMS, as they relate to VSAM KSDS, ESDS,RRDS and AIX file processing: BLDINDEX, DEFINE, DELETE, LISTCAT, PRINT,REPRO and VERIFY. DELETE, PRINT, REPRO and VERIFY provide the sameservices for IAM files as they would VSAM clusters.

IDCAMS DEFINE will create an IAM file whenever the OWNER($IAM) parameter isspecified, '$IAM' is placed somewhere in the data set name, or $IAM is part of the DataClass or Storage Class name.

LISTCAT ALL displays IAM files as non-VSAM in its standard SYSPRINT report.LISTCAT ALL also displays the file's IAM characteristics in an IAMPRINT DD report,which will be dynamically allocated if necessary.

IAM has full support for the SMS environment. This support includes recognizing andusing the SMS classes for allocation, honoring file attributes specified in the Data Class,and support for JCL allocation of IAM files; including temporary data set support. Userscan also use an SMS Data Class name or Storage Class name that contains the literal$IAM to define a file as IAM. When using the SMS JCL allocation feature specifying$IAM in the data set name, in the Storage Class name or in the Data Class name on theDD Statement results in an IAM file being allocated.- 2-2 -

IAM Overview 02.00Activating the IAM VSAM interface is a simple procedure. While evaluating IAM, you canactivate and deactivate IAM at any time. To start IAM all you need to do is submit theprocedure, 'VIFSTART', supplied in the IAM Installation Control Library. Within a fewseconds, IAM will be active in the system. Once testing has been completed and IAM isin production, you can activate IAM automatically each time the system is IPL'd.

Section 90.20 of this manual contains information on how to activate the IAM VSAMInterface.

Record LevelSharing

IAM provides a record level sharing capability that starts within the scope of a singleaddress space, and is extended by IAM/RLS to multiple concurrent online regions andbatch jobs within a z/OS image up to the IAM/PLEX feature that enables IAM datasets tobe concurrently shared across multiple z/OS images within a Sysplex.

IAMs basic processing incorporates a natural record level sharing within the scope of asingle address space. IAM does not lock at the CI level, which can delay access torecords within a CI even when they are not the object of an update process with LSR,but just happen to be in a CI that does contain a record being updated. This is aparticular benefit for online systems, where transactions can be delayed by VSAM dueto the CI lockout process. While many users and CICS itself have implementedstrategies to minimize the CI lockout, it is still an issue with VSAM that doesnt exist withIAM.

IAM/RLS IAM/RLS is a feature included in the base IAM product that provides sharing of IAMdatasets at the record level between multiple concurrently running applications within asingle z/OS image (LPAR). This enables multiple online (CICS) regions to concurrentlyshare IAM files for update with other CICS regions, batch jobs and TSO users. IAM/RLSincludes journaling and recovery capabilities that can be of particular benefit for batchjobs, as CICS already provides recovery for transactions that works with IAM/RLS.

IAM/PLEX IAM/PLEX is an optional additional cost feature to the IAM product that provides recordlevel sharing of IAM datasets across multiple z/OS images (LPARS) that are within aSysplex. IAM/PLEX is built on the framework of the IAM/RLS software with the objectiveof providing an easier mechanism to implement record level sharing at a lower cost thanfull VSAM/RLS implementation. IAM/PLEX includes all the functions of IAM/RLSincluding the journaling and recovery capabilities. The intention of the design of theIAM/PLEX is to provide high availability of data access. IAM/PLEX does not guaranteecontinuous availability or eliminate single points of failure.- 2-3 -

IAM Alternate Index Support 02.1002.10 IAM Alternate Index SupportAlternate Index

SupportIAM offers, at an additional cost, Alternate Index Support. With this optional feature IAMdata sets (both KSDS and ESDS) can have associated alternate index data sets, whichwill also be IAM data sets. All of the features and benefits of IAM are available to baseclusters and all of their related alternate indexes. There are no programming changesnecessary to use the IAM Alternate Index support. No changes are required to CICS.Simply change the define of the base cluster to include either OWNER($IAM) or include$IAM in the base cluster name, or use a DATACLAS or STORCLAS with $IAM in theclass name. Subsequent define steps for any related alternate index data sets or pathswill be automatically converted to IAM, when the base cluster is an IAM data set. Thealternate index support is designed to provide the same high level of compatibility withVSAM alternate indexes that IAM has been providing for KSDS and ESDS types of datasets. Some data set management utility jobs for backing up, restoring, and renamingdata sets involved in a VSAM alternate index relationship will need to be revised.

The IAMAlternate Index

An alternate index provides an additional index to an indexed type of data set (KSDS),or an index to an entry sequence data set (ESDS). Users can define one or morealternate indexes to any base data set. The alternate index data set itself is an IAMKSDS data set that is indexed by the alternate key. The records in the alternate indexcontain some control information, the alternate key, and the primary key value for therecord in the base data set with the corresponding alternate key. An alternate index isdefined as containing UNIQUE keys when there is only one base record with anyspecific alternate key. Alternate indexes can also be defined as containingNONUNIQUE keys, where any particular alternate key can be contained in multiplebase records. As with VSAM, the alternate index data set can be explicitly processed byprograms without referencing the base cluster, or can be used to access the records inthe base cluster. To use an alternate index data set to access the records in the basecluster, a PATH must be defined.

An additional attribute of alternate index data sets is whether they are upgradeable.When an alternate index is defined with the UPGRADE attribute, IAM will automaticallyupdate the alternate index either when updates are made to the base cluster, throughthe primary key or when accessed through an alternate key. Any alternate index definedwith the NOUPGRADE attribute will not be automatically updated by IAM, and it is theapplication programs responsibility to ensure that the alternate index is updated in amanner to remain synchronized with the base data set.

The IAM Path A Path provides the mechanism to access a base cluster through an alternate index.When a path is defined, one must provide the name of the path and the name of therelated alternate index to be used to access the base cluster, or the base cluster to beprocessed whenever the path itself is referenced. The UPDATE or NOUPDATE attributeis specified for each path defined. When a path is defined with the NOUPDATEattribute, any upgradeable alternate indexes will not be updated automatically when thispath is used to access a base cluster either directly or through an alternate index.

For VSAM data sets, a PATH is only a catalog entry that is quite similar to an ALIASentry. With IAM, a PATH will become a one-track data set containing the name of therelated alternate index or base cluster and the UPDATE or NOUPDATE attribute of thePATH. A single track data set was chosen instead of an ALIAS type of catalog entrybecause of concerns about there not being adequate data set management utilityprogram support for ALIAS entries, which might result in the loss of the entry.- 2-4 -

IAM Alternate Index Support 02.10Using an IAMAlternate Index

The procedure for defining and using IAM data sets with alternate indexes is identical tothe VSAM process. The only difference is to specify on the DEFINE that the base clusteris to be an IAM data set. This specification is typically done by either adding theOWNER($IAM) parameter to the define parameters, changing the name to include the$IAM literal, or using a DATACLAS or STORCLAS with $IAM in the class name. Mostapplications that are going to be using IAM for their alternate index already have thegeneral procedures established. To convert to IAM, the only change needed is on thedefine step of the base cluster. An overview of the process for using IAM alternateindexes is described below. All of these steps are covered in detail in the Users Guide(Section 10) of this manual.

Defining the base cluster in Section 10.20.

Loading the base cluster with data. in Section 10.30.

Defining the alternate index(es) in Section 10.61.

Building the alternate index(es) typically done with IDCAMS BLDINDEXcommand in Section 10.62.

Defining paths to the alternate index(es) and if used, paths to the base cluster inSection 10.63.

Using paths to access data in Section 10.64.

Special Considerations with IAM Alternate Indexes in Section 10.65.

In general, there are no JCL changes required when using IAM Alternate Indexes andPaths. To access a base cluster through an alternate index, simply specify the name ofthe Path on the DD statement, just as is done with VSAM. When the Path is opened,IAM will dynamically allocate and open all of the required alternate indexes and theassociated base cluster using the relation information stored within the IAM filestructure. When the Path is closed, IAM will close and de-allocate all of the alternateindexes and the base cluster that were allocated during the open process.

Because the IAM alternate indexes and paths are non-VSAM data sets, they will not beautomatically grouped together in a sphere with their associated base cluster, as istypically done by many data set management utility programs. Some changes to yourdata set management procedures may be necessary when using IAM AlternateIndexes. After renaming a component of an IAM sphere, or performing a restore or copyto a new name, a define recatalog may be necessary. IAM will attempt to automaticallyperform the define recatalog when an IAM AIX is opened when the identical namechange was made to each of the components, that is base cluster, alternate index, andpaths. - 2-5 -

IAM/PLEX: IAM Sysplex Record Level Sharing 02.2002.20 IAM/PLEX: IAM Sysplex Record Level SharingIAM/PLEX The IAM/PLEX feature provides record level sharing support of IAM datasets across

multiple LPARs within a z/OS Sysplex. IAM/PLEX builds upon the IAM/RLS function byutilizing the XCF Sysplex services and the Sysplex Logger to provide a record levelsharing capability for IAM files within a Sysplex. IAMs implementation is an evolutionarystep forward from the basic single system IAM/RLS that utilizes the IAM/RLS frameworkthat has been in use for several years. The IAM/PLEX design is different from VSAM/RLS and is intended to enable users to take advantage of record level sharing withoutthe complexity involved with setting up a VSAM/RLS environment. IAM/PLEX providesthe following capabilities for VSAM applications:

Concurrently share data in IAM files at the record level for update by batch andonline applications from multiple LPARs and systems in a Sysplex. Thiscapability provides improved availability of data on online systems by eliminatingthe need to close files while batch updates are being performed.

Automatic record locking without application program changes. Batch jobs thatdo extensive update activity may need to utilize the IAM sync point process toavoid holding excessive record locks.

Support of the CICS VSAM RLS parameters UNCOMMITTED, CONSISTENT,REPEATABLE, and NOSUSPEND. IAM/PLEX provides equivalent functionalityfor these parameters.

Journaling capabilities that can be used for recovery and auditing purposes.

Capabilities to back out updates for failed applications, including an automaticdynamic back out of updates by a batch job step that abends.

Capabilities to recover datasets that may have experienced a media failure.

Explicit or automatic batch sync point processing for batch jobs that do heavyupdate processing.

IAM/PLEXConcepts

All of the logical and physical I/O processing for files handled by IAM/PLEX will beperformed by an IAM/PLEX address space. IAM/PLEX operates with a concept that anyparticular dataset will be owned by one instance of an IAM/PLEX address space withinthe Sysplex. Each IAM/PLEX instance will be responsible for all the I/O, record locking,and journaling services for the datasets that it owns. I/O requests for IAM datasetshandled by remote IAM/PLEX instance, such as an IAM/PLEX instance on anotherLPAR, will be sent to the owning IAM/PLEX instance by utilizing the z/OS Sysplex XCFsignaling services. The performance of the remote I/O process is dependent on theconfiguration of the XCF communication links between the LPARs.

Datasets that are being processed by IAM/PLEX are assigned an RLSID, which is a fourcharacter identifier specified by the user. The RLSID specifies the named instance ofIAM/PLEX that will be the owner that will process the I/O requests for the subjectdatasets. The RLSID is assigned to a dataset either by the IAM/PLEX dataset nametable, or through the use of IAM CREATE or ACCESS overrides. Each IAM/PLEXinstance is assigned an RLSID through startup parameters. - 2-6 -

IAM/PLEX: IAM Sysplex Record Level Sharing 02.20In addition to the RLSID, each IAM/PLEX instance is assigned to a group of IAM/PLEXinstances referred to as the RLSGROUP. The IAM/PLEX RLSGROUP corresponds tothe z/OS XCF group that will be used for communication within the group. An IAM/PLEXinstance can communicate only with other IAM/PLEX instances that are in the sameRLSGROUP. In effect then, each IAM dataset that is using IAM/PLEX services with anRLSID also becomes a part of the RLSGROUP that the owning IAM/PLEX instance isin. To access that dataset there needs to be an IAM/PLEX instance that is a member ofthat RLSGROUP on each LPAR requiring such access.

IAM/PLEXDiagram

In the above diagram there is one RLSGROUP named RLSPROD, which has two IAM/PLEX instances named RLS1 and RLS2. Each instance is running on a separate LPAR.

LPAR 1

CICS-1 CICS-2

IAM/PLEX

RLSID=RLS1

RLSGROUP=RLSPROD

DSN=PROD.ARLSID=RLS1

DSN=PROD.BRLSID=RLS2

X C F

SHARED DASD

LPAR 2

CICS-3 JOB A

IAM/PLEX

RLSID=RLS2

RLSGROUP=RLSPROD

COUPLING FACILITY

SYSTEM

LOGGER- 2-7 -

IAM/PLEX: IAM Sysplex Record Level Sharing 02.20For example lets say that CICS-1 wants to read a record for update in IAMDSN=PROD.B which is owned by IAM/PLEX_RLS2. CICS-1 issues a standard read forupdate, which IAM processes and sends the request from IAM/PLEX_RLS1 to IAM/PLEX_RLS2 using XCF services. IAM/PLEX_RLS2 will obtain the record lock, retrievethe record, then send the record through XCF back to the CICS-1 address spacethrough IAM/PLEX_RLS1. In this scenario, IAM/PLEX_RLS1 is known as the router,and IAM/PLEX_RLS2 is the target. - 2-8 -

IAM/PLEX: IAM Sysplex Record Level Sharing 02.20IAM/PLEXConfigurations

When configuring how to set up an IAM/PLEX, there are some basic concepts that formthe foundation of how IAM/PLEX works. The most essential basic concepts are thefollowing:

1. A job step, a CICS region, or any other address space can directly connect toonly one IAM/PLEX instance. All of that user address space communicationwith other IAM/PLEX instances will be through that one IAM/PLEX instance.Therefore all of the IAM datasets that an address space accesses through IAM/PLEX must be owned by an IAM/PLEX instance that is within the sameRLSGROUP.

2. Any particular dataset can only be owned by one IAM/PLEX instance. Thereforeany user address space that needs to access that dataset through IAM/PLEXmust be either directly connected or remotely connected through the sameRLSGROUP.

3. An IAM/PLEX instance can belong to only one RLSGROUP.

4. There can be multiple RLSGROUPs within a Sysplex. Each RLSGROUP iscompletely independent of the other RLSGROUPs. Examples might be aproduction RLSGROUP, and a test RLSGROUP. Or there could beRLSGROUPs for different business units, where each group has its own set ofunique datasets with no need to access datasets in different RLSGROUPs.

5. There can be multiple instances of IAM/PLEX address spaces on a singleLPAR. When multiple IAM/PLEX instances that are members of the sameRLSGROUP are active on the same LPAR only one instance will be eligible fordirect connection by users on that LPAR. The other instances of the sameRLSGROUP are treated as remote instances with services provided throughXCF.

6. A shared Sysplex system logger is required if journaling is being used.

7. Persistent record lock support is available with the use of a Record Lock Journaldataset. If an IAM/PLEX instance is recycled, the record locks it held at the timeit was shut down or failed will be reestablished by reading the Record LockJournal dataset and the Sysplex system logger. Each instance of an IAM/PLEXthat owns datasets will need its own Record Lock Journal to facilitate thisprocess.

8. An automatic disconnect and reconnect function is available for CICS regionsthat are utilizing IAM/PLEX services. This will help prevent the need to recycleCICS regions, automatically re-open files that were being processed at time offailure when the IAM/PLEX instance is available and initiate any transactionbackouts that may be necessary due to the failure.

9. Based on our testing configuration, while a Coupling Facility can be utilized forXCF communications, the performance is significantly better through the use ofchannel to channel (CTC) type links. Our configuration does not have adedicated CF engine, so we do not have any data at this time for that type ofconfiguration. Depending on the workload, multiple pairs of links between eachLPAR involved may be necessary to achieve the desired performance. Thereare many components involved in IAM/PLEX performance, from ourenvironment the XCF communication is the major component utilizing the mosttime.

Please also read the next section, 02.30 on the IAM Record Level Sharing for additionalinformation on the features and capabilities of IAM/PLEX.

Full information on setting up and using IAM/PLEX is in Section 25 of the IAM Manual.- 2-9 -

IAM Record Level Sharing 02.3002.30 IAM Record Level SharingRecord Level

SharingThe IAM single system Record Level Sharing permits multiple jobs, CICS regions andTSO users to concurrently update IAM files, with full data integrity. Locking is performedat the record level, so the different jobs can update records within the same data blockwithout any delay. With this capability built into IAM, customers can come even closer toachieving continuous availability of online transaction processing systems. IAMsRecord Level Sharing additionally provides for journaling file update activity, and theability to either backout updates from failing batch jobs or TSO users, or to perform aforward recovery if an IAM file had to be restored from an earlier backup.

IAM/RLS is easy to use. The setup checklist for preparing for IAM/RLS includes thefollowing:

1. Allocating an IAM/RLS parameter library, and choosing the startup parameters.

2. Allocating the IAM/RLS journal data sets, if journaling is going to be used, andsetting up backup and empty procedures for the journal data sets.

3. Allocate a Record Lock Journal for each IAM/RLS address space for thepersistent record lock capability.

4. Deciding on eligibility criteria for IAM/RLS usage and building the data set nametable if it is going to be used. Set the desired option for RLS processing in theIAM Global Options Table.

5. Setting up the IAM/RLS proc from the example provided in the IAM InstallationControl Library (ICL), and placing it in a system procedure library.

6. Start the IAM/RLS procedure. This can even replace the IAMSTART procedurein existence today, because starting up IAM/RLS will automatically start up theIAM VSAM Interface if it is not already active.

Once IAM/RLS is active, data sets will be automatically selected for processing by IAM/RLS, based on installation criteria. Most application programs and jobs will not requireany changes to code or JCL to make use of IAM/RLS. Data sets will have to be definedas IAM data sets. The circumstances where changes are required include:

1. For batch applications that update a large number of records on recoverablefiles, it is necessary to utilize the IAM batch syncpoint process. This can bedone through use of the IAM Override AUTOSYNCPOINT or by revising theapplication program. The maximum number of updated / inserted / deletedrecords to IAM/RLS recoverable files will be limited to the value specified asMAXLOCKS. This limitation is to prevent potential storage shortages andfailures in the IAM/RLS address space. This will also aid in preventing a largenumber of records from being locked out for update by other jobs and CICStransactions.

2. Install and activate the IAM CICS exits that are needed for communicatingtransaction events to IAM/RLS.

The IAM/RLS address space is designed and intended to provide its services in thebackground, with little if any operator intervention. However, should the need arise;there are a variety of commands that can be given to the IAM/RLS address spacethrough the Z/OS MODIFY (F) command. These include display as well as actioncommands. IAM/RLS activity can also be viewed from a TSO/ISPF session, using theprovided IAMBMON program. This program can be invoked either as a TSO commandfrom any ISPF panel, or from the IAM ISPF utility menu.- 2-10 -

IAM Record Level Sharing 02.30IAM/RLSProcessing

Overview

The IAM Record Level Sharing within a single system is achieved by IAM internallypassing all of the I/O requests for the files being shared to the IAM/RLS address space.This is done automatically for files that meet the installations selection criteria, whichcan be determined from a combination of share options and dataset names as set bythe IAM Global Option of RLS. If the IAM/RLS address space has not been activated,and the RLS Global Option has not been changed, then processing for those files will beperformed as it is currently within the jobs address space. The use of IAM/RLS can alsobe controlled by use of the IAM ACCESS overrides of RLS and NORLS.

IAM utilizes z/OS cross memory services to provide the record level sharing services. Allof the OPEN, CLOSE, and I/O requests for shared files will be passed to the IAM/RLSaddress space for processing, and the appropriate status, key and record will be passedback to the users address space when the request has completed within the IAM/RLSaddress sp