Publish-Subscribe Architecture (Explained by Example)

In this video, I want to discuss the Pub sub architecture or publish subsribe architecture and talk about the pros and cons and differences over Request Response. One of you guys asked me which is better REST or Message queue. I struggled to answer for a while but After thinking about it I discovered that both REST and Message queue does boil down to basic elements. REST being HTTP which is Request-Response and Message Queue being Publish subscribe. Timecodes 0:00 Intro 3:00 Where does request response pattern breaks 7:00 Response request pros & cons 11:12 Pub/sub pattern 17:50 Pub/sub pros/cons - [ ] Request/ Response - [ ] Pros and Cons - [ ] Publish-Subscribe Definition - [ ] Pros and Cons Req/res Browsing Fetch or XMLHttpRequest SQL query Pros - Simple to implement (REST) - Stateless (HTTP) - Sync or Async (service and client) Uploading a youtube video - Compress video - format video - Notify subscribers Upload breaks down the video into small chunks and uploads each one Once all successfully uploaded send a whole video to the compress service One video compressed, the compress service sends to the format service and notifications service If you are only using pure request-response, The client will be waiting until all of that stuff is done and if the connection is broken or any failure happens you lose. Plus let's assume You want to also add a feature where the video will need to be checked for copyrighted material.. so the compress service now need to make a request to the copyright service and make sure all of that requests return successfully Cons - Doesn’t scale with multiple receivers - Creates extreme coupling between multiple services - The client and servers have to be running to communicate. - chaining, retries, circuit breaking - Chain effect and circuit breaking (microservices) Meet the publish-subscribe model Ok, this is starting to sound like a commercial. Publish subscribe or pubsub for short is an architecture mo