Types of Communication

• Transient vs. Persistent

  • The server discards messages when they can't be delivered.

  • The server keeps messages until they can be delivered.

• Asynchronous vs. Synchronous

Client/Server

Client/server model based on a synchronous and transient communication model.

• The client and server must be active during the communication.

• The client makes a request and stays locked until it gets an answer.

• The server awaits requests to process.

Problems

• The client can't resume work until it receives the answers.

• Flaws must be processed immediately.

• The model cannot adapt to the problem.

Messages

Message-oriented middleware.

Persistent and asynchronous communication.

Processes exchange messages that are then placed in queues.

Sender does not need to wait for answers.

Flaw tolerance by the middleware.