What is Transaction Server?

A computer network is a framework that associates various autonomous computers to share data (information) and assets. The incorporation of computers and other various gadgets permits clients to communicate without any problem. It is a collection of at least two computer systems that are connected together. An organization association can be laid out utilizing either link or remote media. Equipment and programming are utilized to associate computers and instruments in any organization.

There are various types of computer networks like LAN(local area network), WAN(wide area network), PAN(personal area networks), etc.

Transaction

In simple words, a transaction is the exchange of information between two or more entities affecting each other. In computer networks, a transaction for the most part implies a succession of data trade and related work, (for example, data set refreshing) that is treated as a unit for fulfilling a request and for guaranteeing information base integrity.

All the transactions follow ACID properties to maintain the integrity of the data in databases.

Transaction server

A transaction server is an interaction that runs the pieces of the transaction program that play out the work the client mentioned, normally by reading and composing a common information base, conceivably calling different programs, and perhaps getting an answer that is directed once again to the gadget that gave the contribution to the request.

Some of the examples of commercially available transaction servers are:

• Microsoft transaction server ( MTS )
• IBM transaction server

Transaction servers incorporate programming that handles high volumes of message exchanges. This kind of programming is planned explicitly to deal with enormous volumes of information passage and message traffic in an organization.

• Transaction servers are widely used in relational database system.
• Transaction-server systems, also called query-server systems.
• It provide an interface to which clients can send requests to perform an action, in response they execute the action and send back results to the client.
• Usually, client machines ship transactions to the server systems, where those transactions are executed, and results are shipped back to clients that are in charge of displaying the data.
• Requests may be specified by using SQL.
• Clients send requests to the server.
• Transactions are executed at the server.
• Results are shipped back to the client.

We can understand transaction servers with the analogy of a telephone switchboard that oversees a huge number of messages from clients across the Internet. Below is the basic structure of transaction processing system using transaction server:  

Transaction Server Architecture

Transaction Server Architecture

Server processes

• These receive user transactions, execute them and send results back
• Processes may be multithreaded, allowing a single process to execute several user queries concurrently.
• Typically multiple multithreaded server processes.

Lock manager process

• Manages lock manager functionality.
• It includes lock grant, lock release and deadlock detection.

Database writer process

• Output modified buffer blocks to disks continually.

Log writer process

• Server processes simply add log records to log record buffer.
• Log writer process outputs log records to stable storage.

Checkpoint process

• Performs periodic checkpoints.

Process monitor process

• Monitors other processes, and takes recovery actions if any of the other processes fail.
• E.g., aborting any transactions being executed by a server process and restarting it.

Shared memory contains shared data

• Buffer pool
• Lock table
• Log buffer
• Cached query plans

A typical transaction server consists of multiple processes accessing data in shared memory.

All database processes can access shared memory.

To ensure that no two processes are accessing the same data structure at the same time, databases systems implement mutual exclusion using either

• Operating system semaphores
• Atomic instructions such as test-and-set

How Transaction Server Works?

Suppose, there is a client who wants to access a file from the server, so first of all client makes a connection to the server using TCP protocol, and the translation of the name address into the IP address is done by DNS.

Then they make a request to the server for the particular information or file. This request contains the command, page desired, and the protocol or version. 

After this, the server reads the request and sends the requested file to the client and it is called response. The response contains the status line, header files, and the message body containing the information from the database, and this whole process is called request-response behavior. It might also happen that server denies some information. 

Finally, when the client receives the information, the transaction is terminated.

Components of Transaction Server

• Server(runtime part for dealing with the exchanges and their state occasions)
• User interface ( by which the user and a computer system interact)

Applications of Transaction Server

• It handles a large amount of data entry and traffic in a company.
• It makes System Application Products (SAP) accessible on the Internet. These product items give revealing and insightful devices to organizations.
• These servers also expand the capabilities of SAP.
• A transaction server is most frequently utilized in distributed software architecture.
• Useful in increasing productivity and customer satisfaction.
• It can perform real-time processing and reduce processing time.

Disadvantages of Transaction Server

• The setup cost is high.
• It might happen that software and hardware are incompatible.
• Every server is designed to support only a specific operating system and device.
• Managing a transaction server is complex and requires experience.