Distributed Comet with Lift and Amazon SNS

Transcript

1. Distributed Comet with Lift and Amazon SNS Richard Dallaway @d6y

   Jono Ferguson @jonoabroad Richard@UnderscoreConsulting.com

2. You have multiple users chatting to your server, real-time using

   comet. server1:8080 "Hi" "Hi" Load balancer for http://myapp:80 Easy. All is good in the world.

3. You add another server. server1:8080 "Hi" "Hi" Load balancer for

   http://myapp:80 server2:8081 "yo!" "yo!" How does the "Hi" message get to the "yo" users too?

4. Here's how...

5. During boot, each server registers with a Simple Notification Service

   topic... server1:8080 Load balancer for http://myapp:80 server2:8081 AWS SNS: topic = "chat" Register me to "chat" R server1:/8080/ confirmed! C

6. When someone chats, the message goes to SNS first.... server1:8080

   "Hi" Load balancer for http://myapp:80 server2:8081 AWS SNS: topic = "chat" "Hi"

7. SNS distributes it back to all registered servers (that's what

   SNS does).... server1:8080 Load balancer for http://myapp:80 server2:8081 AWS SNS: topic = "chat" "Hi"

8. Finally, each server can push back to all connected clients.

   server1:8080 Load balancer for http://myapp:80 server2:8081 AWS SNS: topic = "chat" "Hi" "Hi" "Hi" "Hi"

9. Huzzah.

10. Servers are identical. (no special per-instance configuration)

11. Servers don't have to know about each other. (and SNS

    is cheap, fast & reliable)

12. Doesn't have to be SNS. Anything with a publish/subscribe model

    can do this (e.g., RabbitMQ)

13. https://github.com/SpiralArm/liftmodules-aws-sns