Client Server Interview Preparation Guide

With an object server, the Client/Server application is written as a set of communicating objects. Client object communicate with server objects using an Object Request Broker (ORB). The client invokes a method on a remote object. The ORB locates an instance of that object server class, invokes the requested method and returns the results to the client object. Server objects must provide support for concurrency and sharing. The ORB brings it all together.

General middleware
Service-specific middleware.

SQL is a powerful set-oriented language which was developed by IBM research for the databases that adhere to the relational model. It consists of a short list of powerful, yet highly flexible, commands that can be used to manipulate information collected in tables. Through SQL, we can manipulate and control sets of records at a time.

It includes the communication stacks, distributed directories, authentication services, network time, RPC, Queuing services along with the network OS extensions such as the distributed file and print services.

Database Servers
TP Monitors
Groupware
Distributed Objects
Intranets.

In the transaction server, the client component usually includes GUI and the server components usually consists of SQL transactions against a database. These applications are called OLTP (Online Transaction Processing) OLTP Applications typically,

Receive a fixed set of inputs from remote clients.
Perform multiple pre-compiled SQL comments against a local database.
Commit the work and
Return a fixed set of results.

With a transaction server, the client invokes remote procedures that reside on the server with an SQL database engine. These remote procedures on the server execute a group of SQL statements. The network exchange consists of a single request/reply message. The SQL statements either all succeed or fail as a unit.

Task preemption
Task priority
Semaphores
Interprocess communications (IPC)
Local/Remote Interprocess communication
Threads
Intertask protection
Multiuser
High performance file system
Efficient memory management and
Dynamically linked Run-time extensions.

There is no commonly accepted definition for a TP monitor. According to Jeri Edwards' a TP Monitor is "an OS for transaction processing".

TP Monitor does mainly two things extremely well. They are Process management and Transaction management.

They were originally introduced to run classes of applications that could service hundreds and sometimes thousands of clients. TP Monitors provide an OS - on top of existing OS - that connects in real time these thousands of humans with a pool of shared server processes.

TP lite, based on stored procedures.
TP heavy, based on the TP monitors.