Talk held with @grobmeier at W-JAX-2013 https://www.innoq.com/de/talks/2013/11/logging-und-metriken-naher-dran-statt-nur-dabei/

1. Logging & Metrics
Tammo van Lessen Christian Grobmeier
@taval @grobmeier

2. log.errorſ"Houston?"ƀ;

3. NrɬwLɩsGnT FUCkQJɫYcJ jUQwjIaagt uVimjWTocH
xɪUNWɰXZɨB dtNpSSkɬfw ADjɬɭfqlnt IOHlɫHACmU
mɫJɨiɪgɫɬp wmɬommkSvh ttjWddKɰɩL VZdCOlɮSjg
epqMlTntGL toɯBo00WMi NɪTzEjFɩZɪ rsɰwɪeɨZLɩ
ɬXɭumEbaiu ɭCLɯHBEKɩX PihltWebCI VtuɮxhTBdf
ɯHɪmhqY0ug ɰɨWvNUYCtɯ rMpEVUiwUA lɯSaAnGNto
nPcoiO0rhq TYtɫpMrnrt HOUSTON!!! ɭVKJqPAnbO
VɰqofvZZfq zɩlɰɮjCNqQ M0IFOjnNyg ɫMBɩbɪqcIH
KXkɬypeVTɭ ZIHciɩrLyi DdLiDNuYhɬ CIhpkɯɰxEa
pKSNIɫzNtB rQɬCAZSUwc MLYɨERwCɯX yZQTzyOpZb
TOOrfLATEv RfLwPsLfpQ ɨcmPmjCXwɭ ɭRXɪrqEqUa
UzzEmCafve BNlRGzhDhɯ ɪtNdDfhQLn TSɬKPpmIOR
sntɯemAsgZ WxKMɩɭsPbt NkAhɯOFRHK rzɫjPlRɪQg
OhoWɰUiOzB RBZcɫNbjCA fgjchgɮKHL pXɰGɪTɫTti

7. MDC to the rescue?
ThreadContext.putſ"loginId", loginƀ;
logger.errorſ"Something bad happened!"ƀ;
ThreadContext.clearſƀ;
+ Layout:
%-ɬp: %m%n %X{loginId}
Could log:
ERROR: Something bad happened! @grobmeier

8. Enough?

9. Dealing with the Stream Of
Logs
Flume, Kafka, Logstash, Graylog2, Fluentd

10. Searching logs
Graylog2, ElasticSearch

11. Having an overview

13. A Logstash Cluster
From the Logstash docs

14. May I help you?
FluentD (AL 2.0)
Graylog 2 (GPL)
Loggly (commerical)

15. If you want to know...
...you need to log.

16. How much is healthy?

17. Trace is almost for free.
Log4j 2 Filters help too.

18. Default Levels
Files? Warn only.
Logstash & Co? Info.
Magic bugs + advanced setup? Debug, or even trace.

19. Start with verbs
DEBUG adding user @grobmeier on node "baldur"
DEBUG removing user @taval on node "mjölnir"
DEBUG created entry for @taval on node "baldur"
Idea taken from TJ Holowaychuk

20. Logging is cool.
Can I use it to get a health status of my
systems?

21. You can!
But you shouldn't!

22. Metrics
Business Metrics
Application Metrics
System Metrics

23. Gauges
An instrument that measures a value.

24. Counters
A counter is a simple incrementing and decrementing integer.

25. Histograms
A Histogram measures the distribution of values.

26. Meters
A meter measures the rate at which a set of events occur.

27. Timers

37. Dashboards

38. Graphite

39. Cubism.js
Mirror Offset 1 − +
Credits: Michael Bostock

41. Comparisons
var cube = context.cubeſ"http://..."ƀ,
primary = cube.metricſ"sumſrequestƀ"ƀ,
secondary =
primary.shiftſ-ɮ * ɩɫ * ɭ0 * ɭ0 * ɨ000ƀ;

42. Graphene
...

43. Dashing
...

44. Best practices
Measure everything!
Counters ./. Meters
Metrics are cheap, but not for free.
Retention Policies

45. Prevent the apocalypse!
Logging shows events.
Metrics shows state.

46. Thank you!
We use Twitter!
@taval, @innoq & @grobmeier

47. Credits
Holzstapel
CPU by mbostock
Mess by Rev Stan
Debt by "Images Money" (Flickr)
Pay Here by Marc Falardeau
Cockpit by Ronnie Rams
Stream by Phil Whitehouse
Magnifier by John Lodder (Flickr)
Flying Saucer, Cup, and Teapot! by Mr Thinktank
Ice berg by Derek Keats
Gas Meters by mxmstryo (Flickr)
Gauge Stock by Andrew Taylor (Flickr)
Counter by Marcin Wichary (Flickr)
Histogram of legos by color frequency by Jeff Boulter (Flickr)
pomodoro timers by Paul Downey (Flickr)
Zombie Apocalypse by pasukaru76