Define middleware software How is it implemented Note Subjec

Define middleware software. How is it implemented?

Note: Subject is Grid Computing.

Solution

Middleware software act as glue between operating system and application or between database and application. It take services from operating system or database, enhance it and give it to application. It helps application to communicate with different heterogeneous operating system.

Since grid computing is combination of computer (heterogeneous operating system) and communication network (Internet) we need middleware to communicate between different operating system. For e.g. If a computer in grid using Linux and other computer in grid is using windows or UNIX so it is difficult for an application to communicate between them. So we use middleware in grid environment which can provide communication between different computer. Thus middleware provides interoperability between the computers in the grid.

With the help of middleware user can submit there program to execute jobs to the grid. Beside this grid middleware also provide security to the users in the grid and saves lots of time of users.

Implementation of grid middleware software

Component of middleware

Connectivity layer

Resource layer

Collective layer

A middleware class provides four handler functions, one for processing each of the four kinds of messages transports, applications and dispatchers typically send and receive (i.e. inbound user messages, outbound user messages, event messages and failure messages).

Although transport and application middleware potentially both provide the same sets of handlers, the two make use of them in slightly different ways. Inbound messages and events are published by transports but consumed by applications while outbound messages are opposite. Failure messages are not seen by applications at all and are allowed only so that certain middleware may be used on both transports and applications. Dispatchers both consume and publish all kinds of messages except failure messages.