Rhebok

Rhebok is High Performance Rack Handler/Web Server. 2x performance when compared against Unicorn.

Rhebok supports following features.

• ultra fast HTTP processing using picohttpparser
• uses accept4(2) if OS support
• uses writev(2) for output responses
• prefork and graceful shutdown using prefork_engine
• hot deploy using start_server
• only supports HTTP/1.0. But does not support Keepalive.
• supports OobGC

This server is suitable for running HTTP application servers behind a reverse proxy like nginx.

Installation

Add this line to your application's Gemfile:

gem 'rhebok'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rhebok

Usage

$ rackup -s Rhebok --port 8080 -O MaxWorkers=5 -O MaxRequestPerChild=1000 -O OobGC=yes -E production config.ru

Sample configuration with Nginx

nginx.conf

http {
  upstream app {
    server unix:/path/to/app.sock;
  }
  server {
    location / {
      proxy_pass http://app;
    }
    location ~ ^/(stylesheets|images)/ {
      root /path/to/webapp/public;
    }
  }
}

command line of running Rhebok

$ start_server --path /path/to/app.sock --backlog 16384 -- rackup -s Rhebok \
  -O MaxWorkers=5 -O MaxRequestPerChild=1000 -E production config.ru

Options

ConfigFile

filename to load options. For details, please read Config File section

Host

hostname or ip address to bind (default: 0.0.0.0)

Port

port to bind (default: 9292)

Path

path to listen using unix socket

BackLog

specifies a listen backlog parameter

MaxWorkers

number of worker processes (default: 5)

MaxRequestPerChild

Max number of requests to be handled before a worker process exits (default: 1000) If set to 0. worker never exists. This option looks like Apache's MaxRequestPerChild

MinRequestPerChild

if set, randomizes the number of requests handled by a single worker process between the value and that supplied by MaxRequestPerChlid (default: none)

Timeout

seconds until timeout (default: 300)

OobGC

Boolean like string. If true, Rhebok execute GC after close client socket. (defualt: false)

MaxGCPerRequest

If gctools is available, this option is not used. invoke GC by GC::OOB.run after every requests.

Max number of request before invoking GC (defualt: 5)

MinGCPerRequest

If set, randomizes the number of request before invoking GC between the number of MaxGCPerRequest (defualt: none)

SpawnInterval

if set, worker processes will not be spawned more than once than every given seconds. Also, when SIGUSR1 is being received, no more than one worker processes will be collected every given seconds. This feature is useful for doing a "slow-restart". See http://blog.kazuhooku.com/2011/04/web-serverstarter-parallelprefork.html for more information. (default: none)

Config File

load options from specified config file. If same options are exists in command line and the config file, options written in the config file will take precedence.

$ cat rhebok_config.rb
host '127.0.0.1'
port 9292
max_workers ENV["WEB_CONCURRENCY"] || 3
before_fork {
  defined?(ActiveRecord::Base) and
    ActiveRecord::Base.connection.disconnect!
}
after_fork {
  defined?(ActiveRecord::Base) and
    ActiveRecord::Base.establish_connection
}
$ rackup -s Rhebok -O ConfigFile=rhebok_config.rb -O port 8080 -O OobGC -E production
Rhebok starts Listening on 127.0.0.1:9292 Pid:11892

Supported options in config file are below.

host

port

path

backlog

max_workers

timeout

max_request_per_child

min_request_per_child

oobgc

max_gc_per_request

min_gc_per_request

spawn_interval

before_fork

proc object. This block will be called by a master process before forking each worker

after_fork

proc object. This block will be called by a worker process after forking

Signal Handling

Master process

• TERM, HUP: If the master process received TERM or HUP signal, Rhebok will shutdown gracefully
• USR1: If set SpawnInterval, Rhebok will collect workers every given seconds and exit

worker process

• TERM: If the worker process received TERM, exit after finishing current request

Benchmark

Rhebok and Unicorn "Hello World" Benchmark (behind nginx reverse proxy)

ruby version

$ ruby -v
ruby 2.1.5p273 (2014-11-13 revision 48405) [x86_64-linux]

nginx.conf

worker_processes  16;

events {
  worker_connections  50000;
}

http {
  include     mime.types;
  access_log  off;
  sendfile    on;
  tcp_nopush  on;
  tcp_nodelay on;
  etag        off;
  upstream app {
    server unix:/dev/shm/app.sock;
  }
  server {
    location / {
      proxy_pass http://app;
    }
  }
}

config.ru

class HelloApp
  def call(env)
    [ 
      200,
      { 'Content-Type' => 'text/html' },
      ['hello world ']
    ]
  end
end
run HelloApp.new

Rhebok

command to run

$ start_server --path /path/to/app.sock  -- rackup -s Rhebok \
  -O MaxWorkers=8 -O MaxRequestPerChild=0 -E production config.ru

result

$ ./wrk -t 4 -c 500 -d 30  http://localhost/
Running 30s test @ http://localhost/
  4 threads and 500 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     1.85ms    2.94ms 816.72ms   99.24%
    Req/Sec    70.14k     9.13k  110.33k    76.74%
  7885663 requests in 30.00s, 1.29GB read
Requests/sec: 262864.06
Transfer/sec:     44.11MB

Unicorn

unicorn.rb

$ cat unicorn.rb
worker_processes 8
preload_app true
listen "/dev/shm/app.sock"

command to run

$ unicorn -E production -c unicorn.rb config.ru

result

$ ./wrk -t 4 -c 500 -d 30  http://localhost/
Running 30s test @ http://localhost/
  4 threads and 500 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     3.57ms    0.95ms 206.42ms   94.66%
    Req/Sec    35.62k     3.79k   56.69k    77.38%
  4122935 requests in 30.00s, 754.74MB read
  Socket errors: connect 0, read 0, write 0, timeout 47
Requests/sec: 137435.52
Transfer/sec:     25.16MB

Server Environment

I used EC2 for benchmarking. Instance type if c3.8xlarge(32cores). A benchmark tool and web servers were executed at same hosts.

See Also

Gazelle Rhebok is created based on Gazelle code

Server::Stater a superdaemon for hot-deploying server programs

picohttpparser fast http parser

LICENSE

Copyright (C) Masahiro Nagano.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Contributing

1. Fork it ( https://github.com/kazeburo/rhebok/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request