Grow Your Unix Beard Using Ruby

Summary of "Grow Your Unix Beard Using Ruby"

In this talk at RubyConf 2012, Jesse Storimer explores the intricacies of using Unicorn, a web server for Rack applications. He aims to teach attendees about Unix systems programming and how Ruby can interface with it effectively. The presentation promises to demystify the Unicorn web server, showcasing its performance benefits and architectural features that adhere to Unix philosophies.

Key Points Discussed:

Introduction to Jesse Storimer: He introduces himself and shares his journey from Rails programming to diving into lower-level system programming with Ruby.
Unicorn Overview:
- Unicorn is characterized as a Rack HTTP server designed for fast clients and operates through a pre-forking model.
- Discussed features such as how Unicorn handles processes and connections.
Understanding Forking:
- Storimer explains the concept of forking processes, emphasizing how fork in Ruby creates a new process which returns values in two different contexts.
- He illustrates fork by showing how it can be executed in Ruby and its impact on process management.
Pre-Forking Mechanism:
- Pre-forking is highlighted as a way to leverage operating system capabilities by preparing multiple workers to handle incoming connections without needing to reinitialize memory multiple times.
- Through pseudo-code, the mechanism by which Unicorn boots and processes requests is described.
Memory Efficiency with Copy on Write:
- Explained how copy-on-write optimizations allow for memory savings by sharing rather than duplicating data.
- Mentioned that Ruby 1.8 and 1.9 do not utilize this feature effectively.
Zero Downtime Restart:
- Explained how Unicorn can replace itself without losing connections during deployments, illustrating how to maintain service availability.
The Role of exec:
- Introduced the exec system call, which allows replaced processes to maintain their listener sockets, enabling seamless updates to applications.
Concluding Thoughts on Unix Philosophy:
- Storimer advises attendees to embrace the Unix philosophy of specialized tool usage and encourages exploring common system calls beyond web programming.
Final Challenges to the Audience:
- Encourages programmers to explore beyond their usual scope, learn new things, and engage with the powerful features of Unicorn and Ruby.

Key Takeaways:

The importance of understanding how Unix systems programming can enrich Ruby applications.
A strong recommendation to explore Unicorn’s source code and its elegant design patterns that enhance performance for Ruby applications.

Grow Your Unix Beard Using Ruby
Jesse Storimer • Denver, Colorado • Talk

Date: November 01, 2012
Published: March 19, 2013
Announced: unknown

Ruby, like Perl before it, has great support for systems programming and interfaces to common system calls. Unfortunately, this doesn't get talked about much in the Ruby community. In an age where alternative runtimes and threads are getting lots of attention many of the largest Rails deployments are running on single-threaded, blocking I/O, preforking web server called Unicorn.

This talk will be a safari tour through the unique features and internals of Unicorn. By strongly following the Unix philosophy of 'doing one thing well' Unicorn has carved out a reputation as a high-performance, dependable choice for Ruby apps.

The Unicorn codebase is the best, most comprehensive example of Unixsystems programming in Ruby that I've come across. You'll see real-worldexamples of fork(2), accept(2), execve(2), and others. I'll walk throughhow Unicorn distributes connections across a shared socket, how it implements deferred signal handling, how it can replace a running instance of itself without losing any connections. Trust me, by the time it's over you'll begin to feel mysteriously compelled to start growing your Unix beard.

RubyConf 2012