Event Driven Architecture

What’s the difference between a FIFO and a standard queue?

Standard queues guarantee that a message is delivered at least once and duplicates can be introduced into the queue. FIFO queues ensure a message is delivered exactly once and remains available until a consumer processes and deletes it; duplicates are not introduced into the queue.

How can the server be assured a message was properly received?

by recieving a response, else will throw an error.

What classic design pattern is best represented by event driven programming?

Observer pattern.

How do you test an event driven system?

Unit Tests are the most basic tests you will write Your unit test will interact with this class directly, passing various Order values to it, and verifying the tax has been calculated properly.

Terms:

Term	Def
FIFO Queue	FIFO is an abbreviation for first in, first out. It is a method for handling data structures where the first element is processed first and the newest element is processed last
Pub/Sub	Pub/Sub allows services to communicate asynchronously, with latencies on the order of 100 milliseconds.