Presentation for DrupalCon Prague 2013 https://prague2013.drupal.org/session/have-you-been-stalking-your-servers

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

36. Nagios /ˈnɑːɡiːoʊs/
Provides monitoring of:
● network services (SMTP, POP3, HTTP,
NNTP, ICMP, SNMP, FTP, SSH),
● host resources (processor load, disk usage,
system logs),
● anything else like probes (temperature,
alarms, etc).
Many plugins available.

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

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

39. Nagios /ˈnɑːɡiːoʊs/

40. Nagios Addons
NRPE (Nagios Remote Plugin Executor)
- executes plugins on remote Linux/Unix hosts
image source: http://nagios.sourceforge.net/docs/3_0/addons.html

41. Nagios Addons
NSCA
- sends passive checks from remote Linux/Unix
hosts to Nagios
image source: http://nagios.sourceforge.net/docs/3_0/addons.html

42. Drupal and Nagios

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

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

48. Munin Example

49. Drupal and Munin

50. Drupal and Munin

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

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

53. 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)

54. Monitoring APC
Memory Usage, Hit & Misses

55. Monitoring APC
Fragmentation

56. Monitoring APC
memory usage

57. Monitoring APC
files in cache

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

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

60. 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

61. 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

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

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

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

65. 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.

66. puppet – a quick way to start
}

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

68. 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.

69. 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

70. What this gives you

71. What this gives you

72. What this gives you

73. Manifest.pp

74. Manifest.pp

75. Manifest.pp

76. Summary
It is easy to start with monitoring.

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

78. The fun part - what’s wrong?

79. 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

80. 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

81. THANK YOU!
WHAT DID YOU THINK?
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http://prague2013.drupal.org/schedule
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