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