IMS Version 8 Implementation Guide A Technical Overview of the New Features

Chapter 14. Sysplex terminal management 179

14.2 Sysplex terminal management environment

Sysplex terminal management is an optional function of IMS. It is enabled only when IMS is

executing in a Common Service Layer (CSL) environment with shared queues. It utilizes the

services of the Resource Manager with a resource structure to save information about, and

manage the status of, IMSplex VTAM-connected terminal and user resources, and to some

extent, transactions. Figure 14-1 shows a possible configuration of a single IMS in a CSL

environment with shared queues. The shaded area indicates those components used directly

by STM. Additional IMSs in the IMSplex would utilize the same resource and shared queue

structures.

Other IMSs on other OS/390 images would have similar configurations. Each OS/390 image

would require its own SCI address space and each may have a local Resource Manager

address space, although only one RM is required within the IMSplex. There is, of course, a

single Resource Structure and a single set of Shared Queue Structures.

Wherever there is a Resource Manager accessing the resource structure, there must also be

a Common Queue Server. A single CQS address space can provide client services to RM for

the resource structure and to IMS for the shared queue structures. CQS must reside on the

same OS/390 image as its clients (RM and IMS).

Figure 14-1 Sysplex terminal management configuration

14.3 IMSplex resources

IMS resources in an IMSplex include many different types, including IMS system address

spaces, IMS system data sets, IMS defined databases, transactions, and applications,

Resource

List Structure

LOGR

List Structures

SMQ

List Structures

OSAM

Cache Structure

VSAM

Cache Structure

Shared VSO

Cache Structures

IRLM

Lock Structure

VGR

List Structure

MNPS

List Structure

Operations

Manager

(OM)

SCI

Structured

Call

Interface

SCI

SCI

Communications

IMS

Control

Region

S

C

I

Resource

Manager

(RM)

SCI

S

C

I

Common

Queue

Server

(CQS)

180 IMS Version 8 Implementation Guide

dependent regions running application programs, VTAM and OTMA network resources, batch

and utility address spaces, and probably several more. Most of these resources have names

by which they are known to IMS. When IMS systems are cloned, or have similar definitions,

many (or all) of these names are the same throughout the IMSplex and can form the basis for

IMSplex-wide system management functions.

Sysplex

terminal

management addresses the management of a subset of these resources,

primarily those defined as part of the VTAM network. These resources, and the names they

are known by, are shown in Figure 14-2. Note that STM supports neither BTAM nor OTMA

resources.

Figure 14-2 Sysplex Terminal Resources

This figure identifies the resources managed by sysplex terminal management. Each of these

resources can be the source or destination of an IMS message, and has one or more names

associated with it. Each name represents an IMS control block. How IMS handles these

messages is determined solely by its

message destination

name, which usually represents

an anchor block from which to queue the message. Each named resource may be

represented by an entry in the resource structure.

Statically defined VTAM resources (not parallel-session ISC)

Statically defined VTAM resources are defined in the IMS system generation using the TYPE,

TERMINAL, and NAME macros, the NODE name being defined on the TERMINAL macro

and the LTERM name being defined on the NAME macro:

TYPE UNITYPE=SLUTYPE2 (for example)

TERMINAL NAME=NODEname

NAME LTERMname

Static

Dynamic

APPC

ISC

MSC

ISC

Parallel Sessions

Single Session

CF

IMSplex