IMS Connectivity in an On Demand Environment: A Practical Guide to IMS Connectivity

34 IMS Connectivity in an On Demand Environment: A Practical Guide to IMS Connectivity

3.1 Introduction to IMS Connect

IMS Connect is an integrated feature of IMS Version 9 that provides high-performance

communications for IMS between one or more TCP/IP or local z/OS clients and one or more

IMS systems. IMS Connect has the following features:

 Provides commands to manage the communication environment

 Assists with workload balancing

 Supports multiple TCP/IP clients accessing multiple datastore resources

 Reduces design and coding efforts for client applications

 Offers easier e-business access to IMS applications and operations with advanced

security and transactional integrity

IMS Connect is included as part of IMS Version 9 in the IMS system services function

modification identifier (FMID) HMK9900. To provide the same function between one or more

TCP/IP clients and one or more IMS Version 7 or IMS Version 8 clients, IMS Connect is also

available as one of the IBM DB2 UDB and IMS Tools products, IMS Connect Version 2,

Release 2 (program number 5655-K52). IMS Connect Version 2.2 will continue to be

supported for IMS Version 7 and IMS Version 8 clients, but future enhancements to the IMS

Connect functionality will be made available only with IMS Version 9 or later.

The IMS Connect architecture is designed to support any TCP/IP clients communicating with

socket calls. IMS Connect supports TCP/IP sockets access to IMS transactions and

commands. It does not require modifications to the existing IMS transactions.

IMS Connect also supports the TCP/IP clients using the IMS Connector for Java. The IMS

Connector for Java is a collection of Java beans that enable a Java application to

communicate data requests through TCP/IP and the IMS Connect to IMS. IMS Connect with

WebSphere Development Tooling and the IMS Connector for Java can significantly ease the

development of on demand business solutions that access IMS transactions. These solutions

can be deployed in IBM WebSphere Application Server, allowing you to use Web

applications, Java 2 Platform, Enterprise Edition (J2EE) applications, or Web services to

quickly transform static Web sites into sources of dynamic Web content.

IMS Connect with IBM DB2 Version 8, the Universal Database Control Center provides a

single graphical user interface to control both IMS and DB2, easing IMS operations.

3.2 IMS Connect architecture

IMS Connect runs in an address space on a z/OS system and performs router functions

between TCP/IP clients and local option clients with IMS. Figure 3-1 on page 35 shows an

overview of the IMS Connect architecture and introduces the IMS Connect components.

Terminology: By IMS Connect in this redbook, we refer to the integrated IMS Connect

function of IMS Version 9

and IMS Connect Version 2.2, unless explicitly indicated

differently.

Chapter 3. IMS Connect overview 35

Figure 3-1 IMS Connect architecture

IMS Connect interfaces with Open Transaction Manager Access (OTMA) to provide a direct

communication path from clients to IMS applications. OTMA is a feature of IMS that enables

any z/OS client (IMS Connect in this case) to access IMS applications through the

cross-system coupling facility (XCF) services. For additional information about OTMA, see

Chapter 2, “Open Transaction Manager Access” on page 7.

Request messages received from TCP/IP clients, using TCP/IP connections or local option

clients using the z/OS program call (PC), are passed to IMS through XCF. Then, IMS

Connect receives response messages from IMS and passes them back to the originating

TCP/IP or local option clients.

IMS Connect supports TCP/IP clients communicating with socket calls, but it can also support

any TCP/IP client that communicates with a different input data stream format. User-written

message exits can execute in the IMS Connect address space to convert customer message

format to OTMA message format before IMS Connect sends the message to IMS. The

user-written message exits also convert OTMA message format to customer message format

before sending a message back to IMS Connect. IMS Connect then sends the output to the

client.

In addition to TCP/IP client communications, IMS Connect also supports local communication

through the local option. This option provides a non-socket (non-TCP/IP) communication

protocol for use between IBM WebSphere and IMS Connect in the z/OS environment.

Servlets that run in IBM WebSphere Application Server for z/OS and use IMS Connector for

Java can communicate with IMS Connect through the local option.

IBM Software Group

Web server

pgms

Any TCP/IP

client

IMS

Connector

for Java

Solid IMS-based

Architecture

TCP/IP clients

IMS Connect

XCF

SOCKET

calls

...

BPE

Environments (EVC)

TCP/IP

Driver

(Socket

Calls)

IMS

Control

Region

SCI

Operations

Manager

(OM)

SCI

transactions

and cmds

Comm.

Analyzer

(DDMs)

APPC

LU Manager

SCI

IMS

Control

Region

XCF OTMA

SCI

IMS Control

Center

Command Component (CMD)

Call Interface

enhanced commands

TCP/IP client

Comm.

component

(CCC)

Local

Option

Drive

Local Option

Comm.

Component

Datastore

Comm.

component

OTMA

Driver

(XCF

services)

IMSplex

Comm.

Component

IMSplex

Driver

Structured

Call

Interface

SCI