Slides are online already
Random nuggets from the talk:
The overhead of most requests is calls out of a framework to a DB, FS etc, but because it is called from the framework, that is what gets the blame. This sustains the myth that “<insert your framework of choice> doesn’t scale”. Solution: put a proxy in front of the server and duplicate the server behind it.
Types of proxy:
Transparent Cut-Through Proxy = 90% use case
- Transparent Proxy – user cannot detect he is behind a proxy
- Cut-Through – forwards on the fly (not store and forward)
Flaws of Staging environments:
- Any change in profile of queries invalidates your testing
- What if you could take your production traffic and fork it to two environments
- EventMachine inplements a design pattern knows as the reactor pattern
- Will connect to any file descriptor (e.g. a socket)
- Written in C++ for high performance and concurrency without threads
- EM does have a native thread pool used for EM.defer
- http://bit.ly/aiderss-eventmachine excellent PDF to document EM
- A simple DSL for writing proxy servers.
- The return from on_data and on_response blocks is just passed on/back.
- If you return nil from a block, no data gets forwarded.
- 5% performance hit for large messages
- 20% perforamnce hit if messages are very small, mitigate by putting behind HA proxy and add another server.
- No way to send to only 1 back-end server yet (can’t implement a load-balancing proxy).
- httpperf is really good for replaying traffic against a site
- igrigorik/autoperf – replay nginx logs against your site
- Recommended we look at MySQL proxy – awesome dashboard.
- Nginx does really good things with compression (gzip, ETAGS etc).
- Mailtrap is a fake SMTP server gem for testing sending email from your Rails app.
- Defensio is a smap filter for blogs. API you can send comments to and it will tell you if it is spam or not. Returns a ‘spam index’.
- Beanstalk is an in-memory distributed message queue. Despite frequent requests, they have not implemented persistence, which is what motivated Ilya to work around them with this proxy server.
About the Author