These are my reading notes for Code Fellows
SNS = simple notification service. Fan-out approach. If other people care about an event, this is what you should use.
SQS = simple queue service. If YOUR SYSTEM cares about an event, this is what you should use.
Standard queues provide at-least-once delivery, which means that each message is delivered at least once. FIFO queues provide exactly-once processing, which means that each message is delivered once and remains available until a consumer processes it and deletes it. (source)
I don’t really understand this question. In what context is it asked? It wasn’t in the video we were assigned, and is too vague to google.
Publish/Subscribe Pattern
The best way I’ve found online is end-to-end testing:
This is the ultimate ‘it works’ validation, that ensures that the contracts covered in the service tests ‘meet’. In other words — these tests connect the dots between individual services and ensure that what service A needs, is in fact what service B is delivering. (source)
…a method for organising the manipulation of a data structure (often, specifically a data buffer) where the oldest (first) entry, or “head” of the queue, is processed first. (source)
…a messaging pattern where senders of messages, called publishers, do not program the messages to be sent directly to specific receivers, called subscribers, but instead categorize published messages into classes without knowledge of which subscribers, if any, there may be. Similarly, subscribers express interest in one or more classes and only receive messages that are of interest, without knowledge of which publishers, if any, there are. (source)
Used by SNS