Youtor
PublishSubscribe Architecture Explained by Example
>> YOUR LINK HERE: ___ http://youtube.com/watch?v=O1PgqUqZKTA
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 model where a publisher posts. a message to a topic (usually in the form of a queue) and clients optionally can subscribe to the topic and get notified when a new message is posted. • Upload breaks down the video into small chunks and uploads each one • Once all successfully uploaded send a whole video to message queue or topic • The compress service subscribes to the topic. The new video will get received by the compress service, compresses the video and publish it back to the topic or queue as a compressed. • The notification and copyright service subscribes to the topic. • Redis/kafka/RabbitMQ • Pub sub • Pros • Scales with many receivers • Loose coupling(publishers don’t know the subs, subs don't know the pubs) • Caching • Work while publishers or subscribers are offline • Great with microservices avoid chaining, retries, circuit breaking • Pairs with event-driven architecture • • Is the pub/sub perfect though? • Decoupling side effect is a serious problem. You just decoupled the sub from the publisher, how do you guarantee to deliver a message? • Cons • Message delivery issues (exactly once delivery ar least once) • The Two Generals’ Problem • Network saturation- (depends on Pubsubs system) in push model clients might get overwhelmed, in pull model false attempts • scaling is still an issue • • 🐘 Postgres Videos • • PostgresSQL • 🧮 Programming Pattern Videos • • Programming Patterns • 🛡 Web Security Videos • • Web Security • 🦠 HTTP Videos • • HTTP • 🏰 Load Balancing and Proxies Videos • • Proxies • 🏭 Software Architecture Videos • • Software Architecture • 🛰 Network Engineering Videos • • Network Engineering • 💾 Database Engineering Videos • • Database Engineering • 🐍 Python Videos • • Python by Example • 🔆 Javascript Videos • • Javascript by Example • Support me on PayPal • https://bit.ly/33ENps4 • • Stay Awesome, • Hussein
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