This document discusses open source logging and metrics tools. It provides an introduction to customizing logs from common daemons and focuses on log aggregation, parsing, and search. It describes a demo setup using the ELK stack to aggregate and visualize logs and metrics from a Drupal site. The document discusses shipping logs with rsyslog and logstash, and parsing different log formats. It also covers monitoring performance with tools like Graphite and Grafana.

1. Open Source Logging
and Metrics Tools
CapitalCamp and Gov Days 2014

2. Introduction

3. Director of Engineering, Phase2
Steven Merrill
Twitter: @stevenmerrill

4. About This Talk
• Let you visualize your data with OSS tools
• Information on customizing logs from common daemons
• Strong focus on log aggregation, parsing, and search
• Information about drupal.org's logging setup
• Some information on performance metrics tools
• Two-machine demo of Drupal and logging tools

5. Demo:
ELK Stack in Action

6. Demo Setup
• 2 Google Cloud Engine g1.small instances
• All instances run collectd to grab system metrics
• 1 'drupal' instance with Apache, Varnish, MySQL, PHP
• 1 'utility' instance with rsyslog host, Jenkins, Graphite,
Grafana, ElasticSearch, Logstash, Kibana, bucky

7. Logs

8. Ceci n'est pas une log

9. Logs are time + data.
Creator of Logstash
Jordan Sissel
“ ”

10. What Are Logs
• Ultimately, logs are about keeping track of events
• Logs are very different; some use custom formats, while
some may be in pure XML or JSON
• Some are one line, some are many, like Java stacktraces or
MySQL slow query logs

11. Who Produces Logs
• Drupal
• nginx
• Apache
• Varnish
• Jenkins
• SOLR
• MySQL
• cron
• sudo
• ...

12. Types of Logs
• Error Logs
• Transaction Logs
• Trace Logs
• Debug Logs

13. Issues With Logs
• Legal retention requirements
• Require shell access to view
• Not often human-parseable
• Cyborg-friendly tooling

14. Solving Problems With Log Data
• Find slow pages or queries
• Sort through Drupal logs to trace user action on a site
• Get an average idea of traffic to a particular area
• Track new PHP error types

15. Shipping Logs

16. Ship Those Logs!
• syslog-ng
• rsyslogd
• Ship syslog
• Ship other log files
• Lumberjack (logstash-
forwarder)
• Beaver

17. Shipping Concerns
• Queueing
• Behavior when shipping
to remote servers
• Max spool disk usage
• Retries?
• Security
• Encrypted channel
• Encrypted at rest
• Access to sensitive data

18. Configuring rsyslogd Clients
• Ship logs to another rsyslog server over TCP
• *.* @@utility:514
• This defaults to shipping anything that it would normally
log to /var/log/syslog or /var/log/messages

19. Configuring rsyslogd Servers
• Prevent remote logs from showing up in /var/log/messages
• if $source != 'utility' then ~
• Store logs coming in based on hostname and date
• $template DailyPerHostLogs,"/var/log/rsyslog/%HOSTNAME%/
%HOSTNAME%.%$YEAR%-%$MONTH%-%$DAY%.log"
*.* -?DailyPerHostLogs;RSYSLOG_TraditionalFileFormat

20. Configuring rsyslogd Shipping
• Read lines from a particular file and ship over syslog
• $ModLoad imfile
$InputFileName /var/log/httpd/access_log
$InputFileTag apache_access:
$InputFileStateFile state-apache_access
$InputFileSeverity info
$InputFileFacility local0
$InputFilePollInterval 10
$InputRunFileMonitor

21. Configuring rsyslogd Spooling
• Configure spooling and queueing behavior
• $WorkDirectory /var/lib/rsyslog # where to place spool files
$ActionQueueFileName fwdRule1 # unique name prefix for spool files
$ActionQueueMaxDiskSpace 1g # 1gb space limit
$ActionQueueSaveOnShutdown on # save messages to disk on shutdown
$ActionQueueType LinkedList # run asynchronously
$ActionResumeRetryCount -1 # infinite retries if host is down

22. Syslog-shipped Log Files
Mar 11 15:38:14 drupal drupal: http://192.168.32.3|1394566694|
system|192.168.32.1|http://192.168.32.3/admin/modules/list
/confirm|http://192.168.32.3/admin/modules|1||php module
installed.
!
Jul 30 15:04:14 drupal varnish_access: 156.40.118.178 - - [30/
Jul/2014:15:04:09 +0000] "GET http://23.251.149.143/misc/
tableheader.js?n9j5uu HTTP/1.1" 200 1848 "http://
23.251.149.143/admin/modules" "Mozilla/5.0 (Macintosh; Intel
Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/36.0.1985.125 Safari/537.36" 0.000757 miss

23. Log Formats

24. Syslog
Apr 11 18:35:53 shiftiest dnsmasq-dhcp[23185]: DHCPACK(br100)
192.168.32.4 fa:16:3e:c4:2f:fd varnish4
Mar 11 15:38:14 drupal drupal: http://192.168.32.3|1394566694|
system|192.168.32.1|http://192.168.32.3/admin/modules/list
/confirm|http://192.168.32.3/admin/modules|1||php module
installed.

25. Apache
127.0.0.1 - - [08/Mar/2014:00:36:44 -0500] "GET /dashboard
HTTP/1.0" 302 20 "https://68.232.187.42/dashboard/" "Mozilla/
5.0 (Macintosh; Intel Mac OS X 10_9_2) AppleWebKit/537.36
(KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36"

26. nginx
192.168.32.1 - - [11/Apr/2014:10:44:36 -0400] "GET /kibana/
font/fontawesome-webfont.woff?v=3.2.1 HTTP/1.1" 200 43572
"http://192.168.32.6/kibana/" "Mozilla/5.0 (Macintosh; Intel
Mac OS X 10_9_2) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/34.0.1847.116 Safari/537.36"

27. Varnish
192.168.32.1 - - [11/Apr/2014:10:47:52 -0400] "GET http://
192.168.32.3/themes/seven/images/list-item.png HTTP/1.1" 200
195 "http://192.168.32.3/admin/config" "Mozilla/5.0
(Macintosh; Intel Mac OS X 10_9_2) AppleWebKit/537.36 (KHTML,
like Gecko) Chrome/34.0.1847.116 Safari/537.36"

28. Additional Features
• Apache, nginx, and Varnish all support additional output
• Varnish can log cache hit/miss
• With Logstash we can look at how to normalize these
• A regex engine with built-in named patterns
• Online tools to parse sample logs

29. Apache
• Configurable log formats are available – http://
httpd.apache.org/docs/2.2/mod/mod_log_config.html
• A single LogFormat directive in any Apache configuration
file will override all log formats
• The default NCSA combined log format is as follows
• LogFormat "%h %l %u %t "%r" %>s %b "%{Referer}i"
"%{User-agent}i"" combined

30. Apache
• Additional useful information:
• %D Time taken to serve request in microseconds
• %{Host}i Value of the Host HTTP header
• %p Port
• New LogFormat line:
• LogFormat "%h %l %u %t "%r" %>s %b "%{Referer}i"
"%{User-Agent}i" %D %{Host}i %p" combined

31. nginx
• Log formats are defined with the log_format directive – http://
nginx.org/en/docs/http/ngx_http_log_module.html#log_format
• You may not override the default NCSA combined format
• log_format combined '$remote_addr - $remote_user [$time_local] '
'"$request" $status $body_bytes_sent '
'"$http_referer" "$http_user_agent"';

32. Apache
127.0.0.1 - - [29/Jul/2014:22:03:07 +0000] "GET /admin/config/
development/performance HTTP/1.0" 200 3500 "-" "Mozilla/5.0
(Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML,
like Gecko) Chrome/36.0.1985.125 Safari/537.36"
!
127.0.0.1 - - [29/Jul/2014:22:03:07 +0000] "GET /admin/config/
development/performance HTTP/1.0" 200 3500 "-" "Mozilla/5.0
(Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML,
like Gecko) Chrome/36.0.1985.125 Safari/537.36" 45304
23.251.149.143 80

33. nginx
• Additional useful information:
• $request_time Time taken to serve request in seconds with
millisecond resolution (e.g. 0.073)
• $http_host Value of the Host HTTP header
• $server_post Port

34. nginx
• New log_format line and example config for a vhost:
• log_format logstash '$remote_addr - $remote_user [$time_local] '
'"$request" $status $body_bytes_sent '
'"$http_referer" "$http_user_agent" '
'$request_time $http_host $server_port';
• access_log /var/log/nginx/access.log logstash;

35. nginx
70.42.157.6 - - [22/Jul/2014:22:03:30 +0000] "POST /
logstash-2014.07.22/_search HTTP/1.0" 200 281190 "http://
146.148.34.62/kibana/index.html" "Mozilla/5.0 (Macintosh;
Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/36.0.1985.125 Safari/537.36"
!
70.42.157.6 - - [22/Jul/2014:22:03:30 +0000] "POST /
logstash-2014.07.22/_search HTTP/1.0" 200 281190 "http://
146.148.34.62/kibana/index.html" "Mozilla/5.0 (Macintosh;
Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/36.0.1985.125 Safari/537.36" 0.523 146.148.34.62 80

36. Varnish
• The varnishncsa daemon outputs NCSA-format logs
• You may pass a different log format to the varnishncsa
daemon; many share the same format as Apache

37. Varnish
• Additional useful information:
• %D Time taken to serve request in seconds with
microsecond precision (e.g. 0.000884)
• %{Varnish:hitmiss}x The text "hit" or "miss"
• varnishncsa daemon argument:
• -F '%h %l %u %t "%r" %s %b "%{Referer}i" "%{User-agent}i"
%D %{Varnish:hitmiss}x'

38. Varnish
70.42.157.6 - - [29/Jul/2014:22:03:07 +0000] "GET http://
23.251.149.143/admin/config/development/performance HTTP/1.0"
200 3500 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4)
AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125
Safari/537.36"
!
70.42.157.6 - - [29/Jul/2014:22:03:07 +0000] "GET http://
23.251.149.143/admin/config/development/performance HTTP/1.0"
200 3500 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4)
AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125
Safari/537.36" 0.045969 miss

39. Automated Tools

40. Proprietary Tools
• Third-party SaaS systems are plentiful in this area
• Splunk
• SumoLogic
• Loggly
• LogEntries

41. Logstash
• http://logstash.net/
• Great tool to work with logs of ALL sorts
• Has input, filter, and output pipelines
• Inputs can be parsed with different codecs (JSON, netflow)
• http://logstash.net/docs/1.4.2/ describes many options

42. ElasticSearch
• http://www.elasticsearch.com/
• A Java search engine based on Lucene, similar to SOLR
• Offers a nicer REST API; easy discovery for clustering

43. Kibana
• Great viewer for Logstash logs
• Needs direct HTTP access to ElasticSearch
• You may need to protect this with nginx or the like
• Uses ElasticSearch features to show statistical information
• Can show any ElasticSearch data, not just Logstash

44. Grok
• Tool for pulling semantic data from logs; logstash filter
• A regex engine with built-in named patterns
• Online tools to parse sample logs
• http://grokdebug.herokuapp.com/
• http://grokconstructor.appspot.com/

45. Example:
Grokking nginx Logs
192.168.32.1 - - [11/Apr/2014:10:44:36 -0400] "GET /kibana/
font/fontawesome-webfont.woff?v=3.2.1 HTTP/1.1" 200 43572
"http://192.168.32.6/kibana/" "Mozilla/5.0 (Macintosh; Intel
Mac OS X 10_9_2) AppleWebKit/537.36 (KHTML, like Gecko)

46. Configuring Logstash

47. Logstash Config
• By default Logstash looks in /etc/logstash/conf.d/*.conf
• You many include multiple files
• Each must have at least an input, filter, or output stanza

48. Logstash Config
input {
file {
path => "/var/log/rsyslog/*/*.log"
exclude => "*.bz2"
type => syslog
sincedb_path => "/var/run/logstash/sincedb"
sincedb_write_interval => 10
}
}

49. Logstash Config
filter {
if [type] == "syslog" {
mutate {
add_field => [ "syslog_message", "%{message}" ]
remove_field => "message"
}
grok {
match => [ "syslog_message", "%{SYSLOGLINE}" ]
}
date {
match => [ "timestamp", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
}
# Parse Drupal logs that are logged to syslog.

50. Logstash Config
date {
match => [ "timestamp", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
}
if [program] == "drupal" {
grok {
match => [ "message", "https?://%{HOSTNAME:vhost}?|%
{NUMBER:d_timestamp}|(?<d_type>[^|]*)|%{IP:d_ip}|(?<d_request_uri>[^
|]*)|(?<d_referer>[^|]*)|(?<d_uid>[^|]*)|(?<d_link>[^|]*)|(?
<d_message>.*)" ]
}
}

51. Logstash Config
if [program] == "nginx_access" {
ruby {
code => "event['duration'] = event['duration'].to_f * 1000.0"
}
}
if [program] == "varnish_access" {
ruby {
code => "event['duration'] = event['duration'].to_f * 1000.0"
}
}
}
}

52. Monitoring and
Performance Metrics

53. Logs vs Performance Counters
• Generally, logs capture data at a particular time
• You may also want to keep information about how your
servers are running and performing
• A separate set of tools are often used to help monitoring
and manage systems performance
• This data can then be trended to chart resource usage and
capacity

54. Proprietary Tools
• Third-party SaaS systems are also plentiful in this area
• DataDog
• Librato Metrics
• Circonus
• New Relic / AppNeta

55. Time-Series Data
• Generally, performance counters are taken with regular
sampling at an interval, known as time-series data
• Several OSS tools exist to store and query time-series data:
• RRDTool
• Whisper
• InfluxDB

56. First Wave: RRD-based Tools
• Many tools can graph metrics and make and plot RRD files
• Munin
• Cacti
• Ganglia
• collectd

57. Second Wave: Graphite
• Graphite is a more general tool; it does not collect metrics
• It uses an advanced storage engine called Whisper
• It can buffer data and cache it under heavy load
• It does not require data to be inserted all the time
• It's fully designed to take time-series data and graph it

58. Grafana
• Grafana is to Graphite as Kibana is to ElasticSearch
• HTML / JavaScript app
• Needs direct HTTP access to Graphite
• You may need to protect this with nginx or the like

59. Collectd
• http://collectd.org/
• Collectd is a tool that makes it easy to capture many
system-level statistics
• It can write to RRD databases or to Graphite
• Collectd is written in C and is efficient; it can remain
resident in memory and report on a regular interval

60. Demo: Graphite /
collectd / Grafana

61. The Drupal.org
Logging Setup

62. Single Log Host Machine
• CentOS 5
• Dual quad-core Gulftown Xeons (8 cores, 16 threads)
• 16 GB RAM
• 600 GB of HDD storage dedicated to Logstash

63. Software
• ElasticSearch 0.90
• Logstash 1.2
• Kibana 3.0.0m3
• Curator 0.6.2

64. Stats
• Consolidating logs from ≈ 10 web servers
• Incoming syslog (Drupal), Apache, nginx, and Varnish logs
• Non-syslog logs are updated every hour with rsync
• > 2 billion logs processed per month
• Indexing is spiky but not constant; load average of 0.5

65. Questions?

66. Resources

67. Links
• http://logstash.net/
• http://elasticsearch.com/
• https://github.com/elasticsearch/kibana/
• http://graphite.wikidot.com/
• http://grafana.org/

68. Links
• https://collectd.org/
• https://www.drupal.org/documentation/modules/syslog
• https://github.com/elasticsearch/logstash-forwarder

69. PHASE2TECHNOLOGY.COM