11. Level 6 Alerting. Automate some of your troubleshooting tasks. Be warned automatically instead of waiting for a user to complain.
12. Level 7 Collect more logs! We may need more sources for some use cases – Like multi-line application logs, firewall logs or even physical access logs.
13. Level 8 Correlation. Manual analysis of all this new data may take too long – Correlate different sources.
17. Type 1 Logs automatically generated from a service. For example apache2.log or mail.log – Usually huge amount of structured, but raw data. jira.graylog2.org:80 x.x.x.x - - [05/Oct/2011:01:47:38 +0200] "GET /browse/WEBINTERFACE-21?page=com.atlassian.jira.plugin.system.issuetabpanels%3Aall-tabpanel HTTP/1.1" 200 7639 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
18. Type 2 Logs sent directly from within your application. Triggered for example by a log.error() call or an Exception catcher. - Possible to send structured via for example GELF 2011-05-29 18:55:51 +0200 [payment] Could not validate credit card: Got HTTP 404 from example.org
19. How to send your logs Don't store the logs in flat files. Send them somewhere to get more value out of them.
21. GELF Graylog extended log format – Let's you structure your logs. Also check out structured syslog. Ruby library, Rack exception notifier and Ruby logger available. ( www.graylog2.org )
23. AMQP Guaranteed and ordered delivery. Very flexible. Easily subscribe to the flow. Use routing keys to structure origin of the logs. Hell yeah, use this if you have an AMQP bus available. (or build one) Check out https://github.com/paukul/amqp_logging
24. Throw the messages out of your app like a hot potato Loose coupling! Your logs should always leave the application without interfering it! Prefer UDP over TCP, decouple AMQP log transports. Catch all exceptions and get back into the app flow.
25. Add more value to your logs For example pre-generate geo information for IP addresses or integrate the time_bandits gem.
26. https://github.com/skaes/time_bandits Completed in 680.378ms (View: 28.488, DB: 5.111(2,0), MC: 5.382(6r,0m), GC: 120.100(1), HP: 0(2000000,546468,18682541,934967)) | 200 OK [http://127.0.0.1/jobs/info] Can generate a deep insight view of your application performance when used with LogJam: https://github.com/alpinegizmo/logjam
27. Where to send your logs There are a lot of tools available.
28. Hosted services: Loggly www.loggly.com Dynamic pricing based on your usage Free for 200MB/day with 1 week retention time UDP/TCP/HTTP API as input for syslog
29. Two more hosted services: www.papertrailapp.com www.logentries.com
34. program { exec "since /var/log/messages" # Ignore certain messages match { pattern: "this is not an error" # Silence the output, ensure no further match attempts. reaction: none # no output break-if-match: yes # don't continue to the next match } match { pattern: "error" } }
37. Open source tools: Graylog2 www.graylog2.org Accepts syslog (TCP/UDP) and GELF (+ AMQP) Rails web interface for filtering, analytics, alerting, reporting, … Stores in MongoDB
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43. Log management use case: API consumer monitoring Something different from the usual alerting, monitoring and reporting.
44. Pre-processor script (or Logstash) parses raw access log (possibly via AMQP), combines multi line log messages of API engine and extracts value.
53. How many calls are done by the iPhone application and how many were it a month ago?
54. Extract everything you might need from the message in a structured format you can easily parse and query later. You already have all the data you need!