Deploying and Monitoring Ruby on Rails

Deploying and Monitoring

Ruby on Rails

A practical guide

Mathias Meyer and Jonathan Weiss, 25.05.2009 Peritor GmbH

Mit ho

tfixes

von Ca

rsten

Borma

nn

2011-

03-05

+ 2013-

02-28

Danke!

Deployment/Scaling/

Caching/Debugging

jan krutisch

mindmatters gmbh&co. kg

jan.krutisch@mindmatters.de

http://mindmatters.de

Mashed

up w

ith...

2011-

03-05

database

client

(Browser)

mongrel

database

client

(Browser)

rails

Heute:

➔ thi

n

(

∨

unico

rn

)

database

client

rails

webserver

Dateisystem

public/

database

client

rails

webserver

Dateisystem

public/

rails

rails

oldschool:

mod_proxy_balancer

oder ein richtiger

balancer

HAProxy, Squid, etc.

mod_passenger

database

client

rails

webserver

Dateisystem

public/

rails

rails

automagisch.

it just works.

5

Infrastructure

Infrastructure

6

Simple Rails Setup

One Rails instance handles all requests

7

8

9

Typical Rails Setup

•! A load-balancer distributes the incoming requests

•! Some load-balancers will deliver static requests themselves •! Several Rails instances handle all requests

10

11

Deployment Questions

Mongrel? Apache? Ebb? FastCGI? mod_rails? Thin? Nginx? Lighttpd? Pound? mod_proxy_balancer? HA-Proxy? Phusion Passenger? Load-balancer? Proxy? Rails Application Server? Swiftiply? Reverse Proxy? Pen?

12

What we are going to cover today

Rails Application Server

•! FastCGI •! Mongrel

•! mod_rails / Phussion Passenger •! JRuby + Glassfish & Co.

Proxy/Web Server

•! Apache2 •! Nginx •! Lighttpd •! HA-Proxy

13

14

FastCGI

•! Protocol to communicate with long-running CGI applications

•! Usage of either mod_fcgi with Apache 1.3 or mod_fcgi with Lighttpd •! Proxy local and remote FastCGI instances

•! Oldest way of deploying Rails •! Deprecated and unstable

15

16

18

19

Mongrel

•! Developed by Zed Shaw as an alternative to FastCGI

•! Complete HTTP-Server that can load arbitrary Ruby-servlets •! Built-in Rails support

20

21

Mongrel

Apache 2.2 – mod_proxy_balancer Lighttpd Nginx HA-Proxy Pound

22

Mongrel Cluster

23

Mongrel Cluster

24

Mongrel and Apache 2.2

Define Mongrel Cluster in Apache

25

Simple Mongrel and Apache 2.2

26

A more complex example

•! Redirect dynamic requests •! Serve static content

•! Support cached pages

•! Support maintenance page •! Enable client-side caching of

images, stylesheets, and JavaScript

27

Mongrel

•! Very robust

•! Strict HTTP parser

•! Easy to debug (HTTP!)

•! Used to be defacto deployment setup with Apache 2.2 and mod_proxy_balancer •! Can be a bit difficult to setup (mongrel_cluster, ports, Apache)

28

29

mod_rails a.k.a Phusion Passenger

•! Module for Apache 2.2 (and Nginx)

•! Allows Apache to control Rails instances

•! Apache starts and stops application instances depending on the application load •! Able to run any Rack-compatible Ruby application (Merb, Sinatra & Co.)

•! Only manages Rails on one host - no remote instances •! Combine with HTTP-Proxy / balancing solution

30

Install Phusion Passenger

Install Apache module

31

Install Phusion Passenger

Install Passenger with nginx (installs custom nginx)

32

Customized Phusion Passenger

Control Rails instance number

33

Control Phusion Passenger

34

Phusion Passenger

35

Phusion Passenger

36

Phusion Passenger

•! Ready for production

•! Makes setup easier – on the single machine level •! Multiple servers still require load balancer

•! Suitable for mass-hosting

37

38

•! Ruby Runtime on the Java Virtual Machine •! Implemented in Java and Ruby

•! Compiles Ruby into Java-bytecode

•! Integrates with Java code and libraries •! Java’s promises of native threads and JIT

•! Allows for Ruby/Rails applications to be packaged as WAR files •! WAR files deployable on any J2EE-container:

39

40

JRuby on Glassfish

41

JRuby on Glassfish

42

Setup JRuby on Glassfish

1.! Download JRuby and Glassfish

43

Warble Configuration

Define min/max Rails runtimes

44

Glassfish for development

Shrunk-down version of Glassfish v3 - packaged as a gem Can run any Rack-based application

Installation:

•! $ jruby -S gem install glassfish •! $ glassfish

45

46

47

Proxy Requirements

•! Hide cluster backend from the user •! Load-balancer backend instances •! Recognize down hosts

•! Fair scheduler

48

Apache 2.2

•! Apache 2.2 introduced mod_proxy_balancer

•! mod_proxy_balancer can speak to multiple backends and balance requests •! Apache can acts as a pure proxy or can also serve static files

49

Apache 2.2

•! Apache 2.2 introduced mod_proxy_balancer

•! mod_proxy_balancer can speak to multiple backends and balance requests •! Apache can acts as a pure proxy or can also serve static files

50

Apache 2.2

•! Apache 2.2 introduced mod_proxy_balancer

•! mod_proxy_balancer can speak to multiple backends and balance requests •! Apache can acts as a pure proxy or can also serve static files

51

Apache 2.2

Pro

•! Stable, robust, and mature

•! Many people know how to work with Apache

•! Integrates well with other modules (SVN, DAV, Auth, …)

Con

•! Apache can be complicated to configure

52

Nginx – From Russia with love

•! Nginx - popular Russian webserver with good proxy support •! Can load-balance multiple backends and deliver static content •! Quite popular with Mongrel as the Rails backend

53

Nginx Configuration

Simple proxy example

Get complete version here:

54

Nginx

Pro

•! Stable, robust, and fast

•! Uses fewer resources (CPU and RAM) than Apache for proxy-mode and static files •! Simpler configuration file

•! Can directly talk to memcached - SSI

Con

•! More documentation would be nice

55

Lighttpd

•! Lightweight and fast webserver •! Balancing proxy support

•! Good FastCGI support

56

Lighttpd Configuration

Simple proxy example

57

Lighttpd

Pro

•! Fast and lightweight

•! Uses fewer resources (CPU and RAM) than Apache for proxy-mode and static files •! Simpler configuration file

Con

•! Unstable for some people •! Slow development cycle

•! More documentation would be nice

•! Configuration file can be too simple (virtual host aliasing) •! No equivalent for many Apache modules

58

HA-Proxy

•! HAProxy – reliable, high performance TCP/HTTP load balancer •! Proxying and content inspection

•! No content serving, just a proxy

•! Mature proxy module (fair scheduler) •! ACL support

59

HAProxy

60

HAProxy

Pro

•! Mature, stable, robust, and fast •! TCP and HTTP balancing

Con

•! Few Rails examples

61

62

Small Site

Recommendation

Apache 2.2 with mod_rails / Phusion Passenger

63

Medium Site

Recommendation

•! Apache/Nginx as the frontend proxy •! Passenger/mod_rails as the backend •! Deliver static files with Apache

64

Large Rails Setup

Recommendation

•! Redundant load-balancer •! Redundant proxy / web •! Passenger/mod_rails

65

Heavy Static Files

Recommendation

•! Deliver static assets

through separate web server farm

66

Java Shop

Recommendation

•! Deliver a Rails-WAR file and you are

done

•! Integrate with existing Java

68

69

70

71

72

73

74

75

Rack Middleware

•! Authentication (HTTP, OpenID) •! Sessions •! Routing •! Caching •! Logging •! Debugging

76

Support

Frameworks

•! Rails •! Merb •! Camping •! Sinatra •! Mack •! Maveric •! Halcyon •! Ramaze •! Rum •! Vintage •! Waves

Web Server

•! CGI •! FastCGI •! Mongrel •! Phusion Passenger •! JRuby Servlets •! WEBrick •! Ebb •! Thin •! LiteSpeed •! Swiftcore •! Unicorn

77

78

Ruby Enterprise Edition

•! Copy-On-Write patches to Ruby 1.8

•! Saves memory when spawning several Rails instances •! Used by Phusion Passenger if available

Dea

d:

➔ 1.

9.3

79

Thin, Ebb, Evented Mongrel & Co.

•! Alternatives to Mongrel

•! Claim to be faster, lighter, and what have you

•! Rendering “Hello World” is usually not your bottleneck

Stick with stable and robust Mongrel, or better yet, with Passenger

Might

be so

mewha

t dated

prozesse (mongrels)

müssen neugestartet

werden.

Bei Passenger:

konfiguration in

ruby-dateien. Yay!

set

:application

,

"name"

set

:repository

,

"http://kenn.i.net/svn/trunk/name"

role

:app

,

"mog.i.net"

role

:web

,

"mog.i.net"

role

:db

,

"mog.i.net"

,

:primary

=>

true

require

'lib/cap/backgroundrb_recipes'

after

'deploy:update_code'

,

:set_symlinks

task

:set_symlinks

do

run

"ln -s #{shared_path}/config/database.yml #{release_path}/config/

database.yml"

run

"ln -s #{shared_path}/data #{release_path}/public/data"

AWE13

Gruppe/

04

danke!

AWE13

Gruppe/

04

danke!

Erweitern um eigene

"Recipes"

Kommandos werden

parallel auf allen Servern

ausgeführt

Unterstützung diverser

SCM-Systeme

Erlaubt (relativ) einfache

rollbacks, jeder

Nicht auf Rails

beschränkt!

80

Infrastructure

Deployment

82

83

84

85

86

87

88

89

What doesn’t Capistrano do?

•! Plan your initial server setup •! Configure basic services

90

Basic Ingredients

•! The cap command •! Variables

•! Roles •! Tasks

91

Basic Ingredients - cap

Your one-stop deployment shop

92

Basic Ingredients - Variables

•! Configure basic project information

•! Override Capistrano’s default assumptions •! Once set, variables are available globally •! Defined using the set method

93

Basic Ingredients - Roles

•! Define types of servers •! Default roles

•! :www •! :app •! :db

•! All can point to the same server •! But all three must be defined

94

Basic Ingredients - Roles

Define custom roles as you please

95

Basic Ingredients - Tasks

•! Define an atomic set of actions for Capistrano •! Can be called from the command line

96

Basic Ingredients - Tasks

97

Basic Ingredients - Namespaces

Group tasks together logically

98

99

Get Your Capistrano On

100

Get Your Capistrano On

101

Capistrano’s Defaults

•! Your SCM is Subversion

•! Deployment directory is /u/apps/#{application_name} •! User for SCM and SSH is the currently logged-in user •! Commands are run with sudo

102

103

Get Your Capistrano On

•! Capistrano expects a directory structure •! Can be created with cap deploy:setup

104

105

The Deployment Lifecycle

Check the prerequisites:

106

The Deployment Lifecycle

Set up your application for the first time

107

The Deployment Lifecycle

The initial deployment

1.! Checks the revision from the local machine

2.! Checks out the code on the remote machines

3.! Sets a link called current pointing to the lates release

4.! Runs the migrations

108

109

The Deployment Lifecycle

Subsequent deployments

1.! Checks the revision from the local machine

2.! Checks out the code on the remote machines

3.! Updates current link

110

111

Common Capistrano Tasks

Deploy and run migrations

Run only the migrations

Restart application servers

112

113

114

115

Deployment Strategies

116

Deployment Strategies

117

Deployment Strategies

Check out locally and transfer

119

120

121

122

123

Callbacks

Execute a task before another runs

Execute a task after another has finished

124

125

126

127

128

129

The Rest

•! Gem dependencies

•! Support for deploying through gateway servers •! Parallel execution on multiple servers

131

Vlad the Deployer

•! Simple, Rake-based deployment solution

132

Vlad the Deployer

Load

133

Vlad the Deployer

134

Vlad the Deployer

•! Simple, sometimes too simple

•! No callback mechanism, instead the Rake syntax must be used

135

Chef

•! System Integration Framework

•! Written in Ruby – inspired by Puppet •! Manage multiple nodes

•! Configuration •! Packages

136

137

Recipes

138

Recipes

139

Recipes

140

chef-deploy

Enable

141

Chef and chef-deploy

•! In heavy development: sometimes unstable and hard to debug •! Be prepared to get your hands dirty

•! Better suited for configuration than deployment •! Community recipes at

154

Infrastructure

Monitoring

155

156

157

158

Monit

•! Process-level monitoring

•! Checks PID-files, ports, and permissions

•! Reacts by executing a script and/or alerting •! Has a web GUI for administering nodes

159

Monit

MySQL

160

Monit

Apache

161

Monit

Mongrel

162

God

•! Ruby-based configuration •! Easily extendible

•! Can work with event- and poll-based conditions •! Comes with less recipes than Monit

163

God

Mongrel

164

Munin

•! Host-level monitoring

•! Master periodically asks nodes for local data

•! Checks system resources and records historical data •! Allows to recognize trends and make predictions •! Alerting support

165

166

167

168

Exception Monitoring

•! Monitor errors raised by your application •! Usually notifying you by email

•! Good old exception_notification Plugin •! Exceptions as a Service

169

170

171

New Relic

•! Rails Performance monitoring •! Live view into your application

172

Other Tools

•! Nagios •! Big Brother •! New Relic RPM •! FiveRuns •! JMX

173

Infrastructure

174

175

Search

Full text search

176

Full Text Search Engine

Separate Service

•! Creates full text index

•! Application queries search daemon •! Index update through application or

database

Possible Engines

•! Ferret •! Sphinx •! Solr •! Lucene •! …