Distributed Systems talk at PDX Python

Transcript

1. Distributed Systems Using Redis Pub/Sub Or, how micro-services can rock

   your socks. Wednesday, April 11, 12

2. Redis • Pub/Sub • Key value store • Fast •

   Interesting data types Wednesday, April 11, 12

3. Pub/Sub • Channel based • Broadcast • Like UDP •

   Doesn’t require a broker Wednesday, April 11, 12

4. from redis import StrictRedis # Instantiate a redis client client

   = StrictRedis() # Turn on Pub/Sub mode pubsub = client.pubsub() # Subscribe to 'in' and start listening. pubsub.subscribe('in') for message in pubsub.listen(): print(message['data']) Wednesday, April 11, 12

5. from redis import StrictRedis # Instantiate a redis client client

   = StrictRedis() # Publish to the 'in' channel client.publish('in', 'Hello World') Wednesday, April 11, 12

6. Gotchas • Subscribe takes your redis client from you •

   listen() is blocking Wednesday, April 11, 12

7. Coupling • Libraries/code • Services Wednesday, April 11, 12

8. • Many definitions • Database-centric • Peer-to-Peer Distributed Systems Wednesday,

   April 11, 12

9. Case Study: ZenIRCBot • IRC is a simple idea •

   Lots of us hang out on IRC • I built it Wednesday, April 11, 12

10. Architecture • Uses Redis for both storage and pub/sub •

    Micro-service Architecture Wednesday, April 11, 12

11. Services • Only require a Redis client and JSON lib

    • Can run anywhere they can get access to Redis • Can be written in any language Wednesday, April 11, 12

12. Protocol • Versioned • Typed Wednesday, April 11, 12

13. { "version": 1, "type": "", "data": {} } Wednesday, April

    11, 12

14. { "version": 1, "type": "privmsg", "data": { "sender": "Wraithan", "channel":

    "#pdxbots", "message": "Hello IRC World!" } } Wednesday, April 11, 12

15. Stuff that is cool • Pub/Sub is cool • Distributed

    processes are cool • Ergo, ZenIRCBot is cool Wednesday, April 11, 12

16. Thanks • [email protected] • http://wraithan.net • https://github.com/wraithan/zenircbot Wednesday, April 11,

    12