Distributed Comet with Lift and Amazon SNS

Description of using Amazon SNS to distribute comet messages around a cluster of Liftweb machines.

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