EM-Proxy

EventMachine HTTP Duplex Proxy: splits any incoming request into two parallel connections to two hosts.

• One of the connections is marked as production: response is forwarded to client

• One of the connections is marked as benchmark: response is buffered by the proxy

• Once both connections are finished, a ‘post processor’ is executed

• Response time + response body is compared and analyzed

Why?

Because sometimes you want to benchmark your new code against the production environment, and this pattern makes it easy to do so! Put up a proxy, customize it, and analyze whatever you want. The client won’t notice a thing.

Example

> ruby server.rb -c demo/duplex_http.yml
> ruby demo/appserver.rb 9001
> ruby demo/appserver.rb 9002

> curl localhost:9000