The document discusses the importance of server monitoring and provides an overview of common monitoring tools. It recommends starting with Nagios and Munin to monitor servers, services, applications and network traffic. The document also introduces Puppet as an easy way to automate the installation and configuration of monitoring tools. It provides a code example that uses Puppet to set up Nagios, Munin and an APC dashboard with minimal effort.

1. Have you been stalking
your servers?

2. Have you been stalking
your servers?
Marji Cermak
Sysadmin & DevOps Engineer at Morpht
marji@morpht.com
@cermakm

3. The rule of 3 things
picture: http://www.flickr.com/photos/helenaperezgarcia/5692392667/

4. The rule of 3 things
1. What is monitoring and why do you want to
monitor
2. Some monitoring tools available for you
3. It is easy to start with monitoring.

5. Part 1
What is monitoring and why do you want to
monitor

6. photo: http://www.flickr.com/photos/tiagopadua/7903366470/

7. Monitoring
Monitoring is an intermittent (regular or
irregular) series of observations in time,
carried out to show the extent of compliance
with a formulated standard or degree of
deviation from an expected norm.
J. M. Hellawell (1991), modified by A. Brown
(2000), http://jncc.defra.gov.uk/page-2268
nature conservation area

8. Why you need to monitor
● to know about the bad news before your
customers (or your boss)

9. Why you need to monitor
● to know about the bad news before your
customers (or your boss)
● to scale up your server in advance

10. Why you need to monitor
● to know about the bad news before your
customers (or your boss)
● to scale up your server in advance
● to tune up your app

11. Why you need to monitor (cont.)
● to prove your uptime of 99.999 :)

12. The fun of the nines
Source: http://en.wikipedia.org/wiki/High_availability
Nines: http://en.wikipedia.org/wiki/List_of_unusual_units_of_measurement#Nines

13. Why you need to monitor (cont.)
● to prove your uptime of 99.999 :)
● to minimise downtime (expensive)

14. Why you need to monitor (cont.)
● to prove your uptime of 99.999 :)
● to minimise downtime (expensive)
● to capture customer information

15. Why you need to monitor (cont.)
● to have data / metrics to diagnose

16. Diagnosing your collected data
watch out for:
● trends

17. Diagnosing your collected data
watch out for:
● trends
● spikes

18. Diagnosing your collected data
watch out for:
● trends
● spikes
● irregularities

19. Diagnosing your collected data
watch out for:
● trends
● spikes
● irregularities
● thresholds

20. Areas to monitor
● network
photo: http://www.flickr.com/photos/misja_klimov/2120956405/

21. Areas to monitor
● network
● server
photo: http://www.flickr.com/photos/johnjack/3666997634/

22. Areas to monitor
● network
● server
● services
photo: http://www.flickr.com/photos/agustingodet/3691794089/

23. Areas to monitor
● network
● server
● services
photo: http://www.flickr.com/photos/agustingodet/3691792393/

24. Areas to monitor
● network
● server
● services
● applications
photo: http://www.flickr.com/photos/cheerfulstoic/942211994/

25. Areas to monitor
● network
● server
● services
● applications
● users
photo: http://www.flickr.com/photos/jimmysmith/99528596/

26. Drupal Areas to monitor?
● network
● server
● services
● applications
● users

27. Drupal Areas to monitor
● network
● server
● services
● applications
● users

28. Drupal Areas to monitor
● network
● server
● services
● applications
● users

29. Drupal Areas to monitor
● network
● server
● services
○ webserver
○ database
● applications
● users

30. Drupal Areas to monitor
● network
● server
● services
○ webserver
○ database
● applications - your Drupal site(s)
● users

31. Drupal Areas to monitor
● network
● server
● services
○ webserver
○ database
● applications - your Drupal site(s)
● users

32. Part 2
Some monitoring tools available for you

33. Meet Nagios, Munin and others
● Nagios
● Munin
● APC dashboard
● related Drupal modules

35. Nagios /ˈnɑːɡiːoʊs/
● system, network and infrastructure
monitoring software application
● monitors and alerts
● many plugins

36. Nagios /ˈnɑːɡiːoʊs/
Name and Pronunciation:
● NetSaint -> "Nagios Ain't Gonna Insist On
Sainthood"
● Agios' a transliteration of the Greek word
άγιος (saint)

37. Nagios /ˈnɑːɡiːoʊs/
● alerts by email/pager/IM...
● alerts to different contacts
● notification escalation
● service / host dependencies
● soft / hard states

38. Nagios /ˈnɑːɡiːoʊs/

39. Drupal and Nagios

41. Munin
● network/system monitoring application
● outputs graphs through a web interface
● many plugins

42. Munin
● master / node architecture
● connects to all nodes at regular intervals
● it uses the RRDtool (round robin database
tool, handles time-series data)

45. Munin Example

46. Drupal and Munin

47. Drupal and Munin

48. ● they complement each other
● nagios normally alerts on one “service”
● munin can be used to correlate different
things
Nagios & Munin

49. APC - what is it?
The Alternative PHP Cache (APC) is a free
and open opcode cache for PHP.

50. APC - what is it?
The Alternative PHP Cache (APC) is a free
and open opcode cache for PHP.
Its goal is to provide a free, open, and robust
framework for caching and optimising PHP
intermediate code.
Inside your webserver (not a webcache)

51. Monitoring APC
Memory Usage, Hit & Misses

52. Monitoring APC
Fragmentation

53. Monitoring APC
memory usage

54. Monitoring APC
files in cache

55. Other monitoring tools
● Collectd
● Graphite
● Shinken
● Sensu
● NewRelic
● Pingdom

56. Part 3
It is easy to start with monitoring.

57. How to install these tools?
Munin
sudo apt-get install munin munin-node
Nagios
sudo apt-get install nagios3
APC dashboard
php.apc script from php-apc package

58. How to configure these?
● It is a bit fiddly
● There are many guides targeting beginners
● You don’t want to do it again and again

59. puppet – a quick way to start
system for automating system administration
tasks

60. puppet – a quick way to start
● a declarative language for expressing
system configuration,

61. puppet – a quick way to start
● a declarative language for expressing
system configuration,
● a client and server for distributing it

62. puppet – a quick way to start
● a declarative language for expressing
system configuration,
● a client and server for distributing it
● and a library for realising the configuration.

63. puppet – a quick way to start
package { 'munin-node': ensure => installed }
service { 'munin-node':
enable => true,
ensure => running,
require => Package['munin-node'],
}

64. puppet – a quick way to start
1. clone the stalk-your-box repo
2. run puppet apply on the code
3. monitor!

65. A quick way to start
$ git clone
git://github.com/morpht/stalk-your-box.git
/tmp/stalk-your-box
Cloning into '/tmp/stalk-your-box'...
remote: Counting objects: 23, done.
remote: Compressing objects: 100% (19/19), done.
remote: Total 23 (delta 1), reused 23 (delta 1)
Receiving objects: 100% (23/23), 11.35 KiB, done.
Resolving deltas: 100% (1/1), done.

66. A quick way to start
$ cd /tmp/stalk-your-box/
$ sudo puppet apply
--modulepath=modules manifest.pp
notice: /Stage[main]/Nagios::Server/Package[nagios3]/ensure: ensure changed 'purged' to 'present'
notice: /Stage[main]/Nagios::Server/File[/etc/nagios3/htpasswd.users]/ensure: created
notice: /Stage[main]/Nagios::Server/Exec[update-nagios-htpasswd]/returns: Adding password for user nagiosadmin
notice: /Stage[main]/Nagios::Server/Exec[update-nagios-htpasswd]/returns: executed successfully
notice: /Stage[main]/Munin::Node/Package[libcache-cache-perl]/ensure: ensure changed 'purged' to 'present'
notice: /Stage[main]/Munin::Node/Package[munin-node]/ensure: ensure changed 'purged' to 'present'
notice: /Stage[main]/Munin::Node/File[munin-node.conf]/content: content changed '{md5}
e486786f866d7d7e025dea401c300e7b' to '{md5}dbf97a87a8da86ef68155815ecae3c1c'
notice: /Stage[main]/Munin::Server/Service[apache2]: Triggered 'refresh' from 1 events
notice: Finished catalog run in 44.26 seconds

67. What this gives you

68. What this gives you

69. What this gives you

70. Manifest.pp
# Execute apt-get update before any package is installed:
exec { 'apt-update':
command => 'apt-get update',
# but don't execute it more than once a day:
unless => 'test $(find /var/cache/apt/pkgcache.bin -mtime 0 | wc -l ) -eq 1',
}
Exec['apt-update'] -> Package <| |>
# Include minimal apache2 installation. Munin server, nagios
# and APC dashboard depend on it.
include 'apache2'

71. Manifest.pp
# Install munin node and munin server:
class { 'munin::node': }
class { 'munin::server':
htuser => 'munin', # Username for basic access auth.
htpass => 'Prague2013' # Password for basic access auth.
}
# Install nagios:
class { 'nagios::server':
contact_email => 'root@localhost', # Email to send alerts to.
htpass => 'Prague2013', # Password for the nagiosadmin username.
}

72. Manifest.pp
# Deploys APC dashboard - install php-apc package and
# deploy the apc.php script from it.
package { 'php-apc': ensure => installed }
exec { 'deploy-apc-dashboard':
path => '/bin:/usr/bin',
command => 'gzip -dc /usr/share/doc/php-apc/apc.php.gz > /var/www/apc.php',
notify => Service['apache2'],
unless => '[ -f /var/www/apc.php ]',
require => [ Package['php-apc'], Package['apache2'] ]
}

73. Summary
It is easy to start with monitoring.

74. The fun part - what’s wrong?
What’s wrong here?

75. The fun part - what’s wrong?

76. Questions
Here is the get started monitoring repo:
https://github.com/morpht/stalk-your-box
Marji Cermak
Sysadmin & DevOps Engineer at Morpht
marji@morpht.com
@cermakm

77. Resources
Rule of Three: en.wikipedia.org/wiki/Rule_of_three_(writing)
Nagios: http://www.nagios.org/
Munin: http://munin-monitoring.org/
Nagios module: https://drupal.org/project/nagios
Munin module: https://drupal.org/project/munin
Munin plugins (experimental): https://drupal.org/sandbox/murrayw/2084281
Sensu: http://sensuapp.org
MySQLTuner: http://MySQLTuner.pl

78. THANK YOU!
WHAT DID YOU THINK?
Locate this session at the
DrupalCon Prague website:
http://prague2013.drupal.org/schedule
Click the “Take the survey” link