open source logging and monitoring tools
DESCRIPTION
A talk about Open Source logging and monitoring tools, using the ELK stack (ElasticSearch, Logstash, Kibana) to aggregate logs, how to track metrics from systems and logs, and how Drupal.org uses the ELK stack to aggregate and process billions of logs a month.TRANSCRIPT
D E V O P S T R A C K , D R U P A L C O N A M S T E R D A M
OPEN-SOURCE LOGG ING AND MONITORING TOOLS
S T E V E N W . M E R R I L L
INTRODUCTION
Director of Engineering, Phase2 Volunteer, drupal.org infrastructure
Steven Merrill
Twitter: @stevenmerrill
ABOUT THIS TALK
• Help 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 and monitoring
• Two-machine demo of Drupal and logging tools
DEMO SETUP
• 2 Google Cloud Engine g1.small instances
• Both instances run collectd to grab system metrics
• 1 'drupal' instance with rsyslog shipping logs, Apache, Varnish, MySQL, PHP
• 1 'utility' instance with rsyslog host, Jenkins, Graphite, Grafana, ElasticSearch, Logstash, Kibana, bucky (statsd)
INITIAL DEMO:ELK STACK IN ACTION
KIBANA
KIBANA
LOGS
CECI N'EST PAS UNE LOG
https://www.flickr.com/photos/data_op/2575797856/
"LOGS ARE TIME + DATA."- Jordan Sissel, creator of Logstash
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
WHO PRODUCES LOGS
• Drupal
• nginx
• Apache
• Varnish
• Jenkins
• ElasticSearch or SOLR
• MySQL
• cron
• sudo
• ...
TYPES OF LOGS
• Error Logs
• Transaction Logs
• Trace and Debug Logs
ISSUES WITH LOGS
• Legal retention requirements
• Require shell access to view
• Not often human-parseable
• Cyborg-friendly tooling
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
LOG FORMATSADDING MORE SMARTS TO YOUR LOGS
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.
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"
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"
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"
ADDITIONAL FEATURES
• Apache, nginx, and Varnish all support additional output
• Time spent processing the request
• Varnish can log cache hit/miss
• Any header
• With Logstash we can normalize these
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
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
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
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"';
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
•$server_post Port
NGINX
• New log_format line and example config for a vhost:
• log_format logstash '$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;
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
VARNISH
• The varnishncsa daemon outputs NCSA-format logs
• You may pass a different log format to the varnishncsa daemon
• Many of the configuration options share the same format as Apache
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'
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
SHIPPING LOGS
SHIP THOSE LOGS!
• syslog-ng
• rsyslogd
• Ship syslog
• Ship other log files
• Logstash
• logstash-forwarder (formerly Lumberjack)
• Beaver
SHIPPING CONCERNS
• Queueing
• Behavior when shipping to remote servers
• Max spool disk usage
• Retries?
• Security
• Encrypted channel
• Encrypted at rest
• Access to sensitive data
SHIP LOGS WITH RSYSLOGD
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
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
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
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$ActionQueueMaxDiskSpace 1g # 1 GB space limit$ActionQueueSaveOnShutdown on # Save messages to disk on shutdown$ActionQueueType LinkedList # Run asynchronously$ActionResumeRetryCount -1 # Infinite retries if host is down
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
AUTOMATED LOG AGGREGATION TOOLS
PROPRIETARY LOG AGGREGATION TOOLS
• Third-party SaaS systems are plentiful in this area
• Splunk
• SumoLogic
• Loggly
• LogEntries
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
ELASTICSEARCH
• http://www.elasticsearch.com/
• A Java search engine based on Lucene, similar to SOLR
• Offers a far nicer REST API; easy discovery for clustering
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
• Logstash JARs/packages can also run Kibana from an embedded server
• ./bin/logstash web -a ADDRESS -p PORT
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/
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) Chrome/34.0.1847.116 Safari/537.36"
CONFIGURING LOGSTASH
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
• Example Logstash configuration follows to parse Drupal and nginx logs from syslog and normalize duration to milliseconds
• The full example is posted at http://git.io/e6TvAg
LOGSTASH CONFIG
input { file { path => "/var/log/rsyslog/*/*.log" exclude => "*.bz2" type => syslog sincedb_path => "/var/run/logstash/sincedb" sincedb_write_interval => 10 } } !output { elasticsearch_http { host => "localhost" flush_size => 5000 } }
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" ] }
LOGSTASH CONFIG
# Parse Drupal logs that are logged to syslog. 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>.*)" ] } }
LOGSTASH CONFIG
# Parse nginx logs that have been shipped over syslog. if [program] == "nginx_access" { mutate { remove_field => [ "path", "pid", "syslog_message", "timestamp" ] } grok { match => [ "message", "%{COMBINEDAPACHELOG} %{BASE16FLOAT:duration} %{IPORHOST:hostname} %{POSINT:port}" ] } # Put the hostname into the request, a la Varnish. if [port] == "443" { mutate { replace => [ "request", "https://%{hostname}%{request}" ] } }
LOGSTASH CONFIG
else { mutate { replace => [ "request", "http://%{hostname}%{request}" ] } } ruby { code => "event['duration'] = event['duration'].to_f * 1000.0" } date { match => [ "timestamp", "dd/MMM/yyyy:HH:mm:ss Z" ] } useragent { source => "agent" target => "browser" } }
MONITORING AND PERFORMANCE METRICS
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
PROPRIETARY METRICS TOOLS
• Third-party SaaS systems are also plentiful in this area
• DataDog
• Librato Metrics
• Circonus
• New Relic / AppNeta
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
FIRST WAVE: RRD-BASED TOOLS
• Many tools can graph metrics and make and plot RRD files
• Munin
• Cacti
• Ganglia
• collectd
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
STATSD
• Statsd is a tool created by Etsy as a simple stats aggregator
• It aggregates counters and sends them to Graphite
• It accepts data over TCP or UDP
• Logstash can increment statsd counters based on log data
• The canonical implementation is node.js, but many ports exist
• statsite (C), bucky (Python)
• For counters, sends raw stats each flush (stats.*) and also event counts per second (stats_counts.*)
LOGSTASH CONFIG
output { if [program] == "varnish_access" { statsd { sender => "%{logsource}" # Count each event based on the HTTP response code. increment => "varnish.response.%{response}" # Also count Varnish hits and misses. increment => "varnish.cache.%{cache}" # Use the 'bytes' field from the varnish log as the count value. count => [ "varnish.bytes", "%{bytes}" ] } } }
GRAFANA
• Grafana is to Graphite as Kibana is to ElasticSearch
• HTML / JavaScript app
• The user's browser needs direct HTTP access to Graphite
• You may need to protect this with nginx or the like
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
DEMO: GRAPHITE / COLLECTD / GRAFANA
MONITORING & METRICS
MONITORING TOOLS
• Monitoring tools
• Nagios
• Icinga
• Sensu
• Zenoss
• Zabbix
• Monitoring check tools
• Monitoring Plugins (née Nagios Plugins)
• https://www.monitoring-plugins.org/
• #monitoringsucks
• #monitoringlove
MONITORING CHECKS
• Monitoring is generally used to get server state.
• Are the web servers online - can I ping them? check_ping
• Is the disk more than 80% full on any of my servers? check_disk
• Is Redis running and responding to a PING command? check_tcp
• Is the load average on any machine over 4? check_load
• Have any Drush processes run for more than 10m? check_procs
METRICS EXAMPLES
• Metrics have far deeper insight into application state.
• How many failed login attempts have happened in the last 10m?
• How many users have logged into the system this week?
• What is the average Varnish cache hit rate over the last 5m?
• How many 404s have we gotten in the last day?
• What is the average backend response time in the last hour?
BRIDGING METRICS AND MONITORING
• Specific metrics values can be very useful to turn into monitoring alerts.
• The https://github.com/heroku/umpire project watches Graphite or Librato Metrics and responds with a HTTP 200 or 500.
• Point check_http checks or external monitoring like Pingdom at it.
• To avoid alert fatigue, try to establish conditions that you know are truly anomalous.
BRIDGING METRICS AND MONITORING
• Example metrics/monitoring bridges with Umpire
• Did the average Varnish cache hit rate fall under 60 over the last 5m?
• /check?metric=statsd.varnish-hit-rate&min=60&range=300
• Did uid 1 have more than 5 failed login attempts in the past 1h?
• /check?metric=statsd.uid-1-login-failure&max=60&range=3600
DEMO: UMPIRE / STATSD
THE DRUPAL.ORGLOGGING SETUP
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
SOFTWARE (CURRENT)
• ElasticSearch 0.90
• Logstash 1.2
• Kibana 3.0.0m3
• Curator 0.6.2
SOFTWARE (THIS WEEK)
• ElasticSearch 1.3.2
• Logstash 1.4.2
• Kibana 3.1
• Curator 2.0.0
STATS
• Consolidating logs from ≈ 10 web servers
• Incoming syslog (Drupal), Apache, and Varnish logs
• Looking to add EdgeCast (CDN) logs if we have capacity
• Non-syslog logs are updated every hour with rsync
• > 2 billion logs processed per month
FINDING A PROBLEM USING LOGHOST
• https://www.drupal.org/node/2186105
• PHP error on saving issues after the Drupal 7 upgrade
• Did a Lucene query to get xjm's PHP errors
• program:drupal AND d_uid:65776 AND d_type:php
• Found PDOExceptions and an issue with a SQL field size
QUESTIONS?
RESOURCES
LINKS
• http://httpd.apache.org/docs/2.2/mod/mod_log_config.html
• http://logstash.net/
• http://elasticsearch.com/
• https://github.com/elasticsearch/kibana/
• http://graphite.wikidot.com/
• http://grafana.org/
• http://www.phase2technology.com/blog/adding-mysql-slow-query-logs-to-logstash/
LINKS
• https://github.com/elasticsearch/logstash-forwarder
• https://collectd.org/
• https://www.drupal.org/documentation/modules/syslog
• https://www.monitoring-plugins.org/
• https://github.com/etsy/statsd/
• https://github.com/heroku/umpire
• http://git.io/e6TvAg - sample Logstash config for Drupal/nginx
SPRINTS!
D E V O P S T R A C K , D R U P A L C O N A M S T E R D A M
WHAT D ID YOU TH INK?E V A L U A T E T H I S S E S S I O N - AMSTERDAM2014.DRUPAL.ORG/SCHEDULE