The full form of MOM is Message-Oriented Middleware which is an infrastructure that allows communication and exchanges the data (messages). It involves the passing of data between applications using a communication channel that carries self-contained units of information (messages).In a MOM-based communication environment, messages are sent and received asynchronously.

MOM provides asynchronous communication, and it just sends the message and performs its asynchronous operations. It consists of inter-application communication software that relies on asynchronous message passing which would oppose request-response architecture. So asynchronous system consists of a message queue that provides a temporary stage so that the destination program becomes busy or might not be connected. Message Queue helps in storing the message on a MOM platform. MOM clients can send and receive the message through the queue.

Queues act as a central component for implementing asynchronous interaction within MOM.

• Middleware is software that acts as a link between two or more objects
• Middleware simplifies complex distributed applications,
• It consists of web servers, application servers, and more, it is integrals to modern information technology based on XML, SOAP, service-oriented architecture.

Block Representation of Middleware:

Middleware

Features and Capabilities 

1. Unified messaging
2. Provisioning and monitoring
3. Dynamic scaling
4. Management and control tools
5. Dynamic scaling
6. Flexible service quality
7. Secure communication
8. Integration with other tools

Structure and working of the Message Queue in MOM:

Message Queue in MOM

MOM enables communication between distributed components. Middleware makes programming easier in a distributed environment. It acts like an Operating System (OS) for distributed computing architecture and provides transparency for the applications.

A message-oriented middleware acts as a middleware for different applications for example:

MOM Deployment

The above diagram is a message-oriented middleware-based distributed system deployment that offers a service-based approach to inter-process communication. The messaging of MOM is the same as the postal service.

The Architecture of Message Oriented Middleware:

Architecture of MOM

Types of middleware:

1. Database Middleware
2. Application Server Middleware
3. Messaging middleware
4. Message-oriented Middleware
5. Transaction processing middleware

Roles of message-oriented middleware

1. The message distribution is enabled over complex IT systems.
2. It servers as a connector for two different applications or platforms.
3. MOM helps in implementing the delivery of messages across different IT organizations.
4. It will create a distributed product that is compatible with the various OS.
5. MOM allows various software components can talk to each other.
6. It is a type of middleware that consists of several lines that are connected to different applications.
7. It connects different technologies involving message origination and delivery destination.
8. It links front and back-end systems.

Example:

MQTT(Message Queuing for Telemetry Transport): Most MQ systems and protocols are aimed at backed and enterprise applications and these types of technologies are not suited for constrained devices like sensor nodes. Such devices are typically constrained in terms of memory, bandwidth, and power.

MQTT is a message-oriented protocol aimed at applications like wireless sensor networks, M2M(mobile 2 mobile) and ultimately the internet of things(a large number of nodes and applications loosely through a messaging system).

Advantages

1. Loose coupling
2. Scalability
3. Fast
4. Reliability
5. Availability

Disadvantage

1. Requires extra component in the architecture
2. Poor programming abstraction
3. One-to-one communication for queue abstraction
4. Not implemented for some platform