A transaction server manages business transactions. It sits in the middle, between the client and the server and acts as glue, holding essential data processing activities together. It allows huge amounts of information to remain accurate and ensures transactions are completed without interruption or data corruption. A transaction server sits right in the middle of a system, managing transactions as they zoom around different networks. The transaction server is responsible for maintaining high performance, availability and data integrity. It also makes sure that no computer has too much or too little to do.

Transaction Server Applications

Transaction servers are best suited to secure, high-speed applications such as:

• E-commerce
• Stock market trading
• Airline reservations
• Credit-card verification
• Online banking transactions

When a transaction server sees that one computer has been sent too much work, it automatically divides the work among all available computers, pooling resources to prevent any one machine from crashing.

When it updates databases, a transaction server also performs what's known as state management. If it senses that a computer can't complete a transaction, it makes the software back out and return to its original state without data corruption.

You don't want half processes. You need to have both databases completely updated and, if the process fails, to back out as if the transaction never occurred.

A Process

A transaction server is considered more of a process than a concrete piece of hardware or software.

It's becoming increasingly rare to see a transaction server sold as a separate product. It's either part of a computer's operating system or part of the middleware — software that sits between a smaller computer, called a client, and a larger one, called a server. Middleware makes sure that when the clients request information, the servers provide it, even though they might be based on different computing platforms.

One of the fundamental characteristics of middleware is independence and openness. It's a generalized infrastructure to which a lot of tools can be applied.

Back in the days of the mainframe, the transaction server was called a transaction monitor. It expanded beyond mainframes to take on the role of administering distributed object-oriented applications in client/server computing.

Object-oriented computer programs are based on software rules that allow little chunks of programs to act as independent objects that work together through the messages passed among them. They are modular and reusable, so programmers don't have to repeatedly write the same objects. They can also swap out one object for another without having to rewrite the entire program.

A transaction server working as middleware also solves a unique problem: At first there were only clients and servers, but there was never a place to execute applications. It was always jammed into the client or into the back-end database. Middleware fills that gap between the client and the server.

Encapsulates Infrastructure

Wherever it resides, the transaction server encapsulates the underlying infrastructure of a program. It provides an environment in which the software developer doesn't have to write underlying code in order to write an application. In the future, it's possible we may not even use the term transaction server because its functions will be rolled into other products.

Additional Types of Middleware

Besides transaction servers, there are five other types of middleware:

• LEGACY [older applications that use different technology than the newer systems installed at an organization]: Pulls together and accesses "legacy" applications.
• DATA ACCESS: Provides synchronous connections among applications and different types of databases to supply the requested data.
• REMOTE PROCEDURE CALL: Provides a link between the requesting application and a remote application
• MESSAGE-ORIENTED: Applications make requests by passing messages directly to middleware with guaranteed delivery. Messages act like records, calling for action and supplying the input needed for that action
• OBJECT-ORIENTED: Supplies and manages communication among distributed objects, which are self-contained, reusable program modules

This conceptual drawing shows the transaction server sitting between the central server and three clients. In the model it's acting as the middleware layer and is:

• Maintaining performance and availability
• Protecting transactions
• Preventing data corruption
• Load balancing to prevent systems from overworking

Transaction Server

IBM's CICS Transaction Server is transaction-oriented middleware infrastructure that enables solution developers to focus on business functionality and end-user issues, rather than the deep, technical issues often associated with middleware.

The benefit to solution developers?

High quality products with faster time to market.

CICS Transaction Server plays a key role in distributed application processing. CICS Transaction Server which includes products such as CICS Clients, provides functions and services that simplify application development and cross platform implementation. CICS Transaction Server also takes advantage of the robustness of the OS/390 platform thus delivering highly available and scalable solutions. With the CICS Client technology being incorporated in the CICS Transaction Server package, this delivers a simple API for modifying applications to provide client server CICS solutions.

A first step in partnering with IBM is joining the IBM Transaction Server Partners in Development program. Joining the Transaction Systems Partners in Development program allows you gain access to the tools and resources needed for developing your CICS-enabled applications. This program is also designed for solution developers who develop or port TXSeries-based solutions to client/server environments.

Why not become a member today?