Presentation done at the Portuguese JUG http://jug.pt/, about the metrics library from Yammer http://metrics.codahale.com/.

1. metrics
performance monitoring
or business value optimization?
Terça-feira, 29 de Janeiro de 13

2. Me
Terça-feira, 29 de Janeiro de 13

3. • CTO at Cult of Bits
• 10+ years of professional Java development
Me
Terça-feira, 29 de Janeiro de 13

4. Why?
Terça-feira, 29 de Janeiro de 13

5. Ultimately it’s about
Business Value
Why?
Terça-feira, 29 de Janeiro de 13

6. To make informed Business
decisions we need to know
the reality of our software
Why?
Terça-feira, 29 de Janeiro de 13

7. How many errors are our
users seeing?
Why?
Terça-feira, 29 de Janeiro de 13

8. Is our App fast enough?
Why?
Terça-feira, 29 de Janeiro de 13

9. Were our assumptions about
performance/usage patterns
proven correct?
Why?
Terça-feira, 29 de Janeiro de 13

10. The Metrics
library
Terça-feira, 29 de Janeiro de 13

11. Metrics is a Java library which gives you unparalleled
insight into what your code does in production.
Developed by Yammer to instrument their JVM-based backend services,
Metrics provides a powerful toolkit of ways to measure the behavior of
critical components in your production environment.
source: http://metrics.codahale.com/
The metrics library
Terça-feira, 29 de Janeiro de 13

12. Types of Metrics
Terça-feira, 29 de Janeiro de 13

13. • Gauges
• Counters
• Histograms
• Meters
• Timers
Types of Metrics
Terça-feira, 29 de Janeiro de 13

14. Structure of
metrics
Terça-feira, 29 de Janeiro de 13

15. Group Top level grouping (“package name”)
Type Second level grouping (“class name”)
Name the metric name (e.g.,“error-count”)
Scope optional
Structure of metrics
Terça-feira, 29 de Janeiro de 13

16. Outputs
Terça-feira, 29 de Janeiro de 13

17. • JMX
• Console
• CSV files
• JSON servlet
• Graphite
• Ganglia
Outputs
Terça-feira, 29 de Janeiro de 13

18. DEMO TIME
Terça-feira, 29 de Janeiro de 13

19. What to measure?
Terça-feira, 29 de Janeiro de 13

20. “If it could affect business value, measure it”
Coda Hale - metrics’ author
At yammer they can have up to 40/50 metrics per service
What to Measure?
Terça-feira, 29 de Janeiro de 13

21. REST requests
Timer
What to Measure?
Terça-feira, 29 de Janeiro de 13

22. MySQL/couchdb/Solr queries
Timer
What to Measure?
Terça-feira, 29 de Janeiro de 13

23. Calls to external services/processes
Timer
What to Measure?
Terça-feira, 29 de Janeiro de 13

24. Dimensions of requests/responses
Histogram
Examples:
•Search “page” size
•Depth of search requests
•Number of search terms used
What to Measure?
Terça-feira, 29 de Janeiro de 13

25. ERRORS!
Counter / Meter
What to Measure?
Terça-feira, 29 de Janeiro de 13

26. The CoB
experience
Terça-feira, 29 de Janeiro de 13

27. Our use-case
Terça-feira, 29 de Janeiro de 13

28. • Lots of applications in different
sites
• 1-3 servers
• No full-time network access
Our use-case
Terça-feira, 29 de Janeiro de 13

29. lessons learned
Terça-feira, 29 de Janeiro de 13

30. Naming metrics can be hard
lessons learned
Terça-feira, 29 de Janeiro de 13

31. Creating metrics is just the
start
lessons learned
Terça-feira, 29 de Janeiro de 13

32. Having hard data to help
decision is pricelless
lessons learned
Terça-feira, 29 de Janeiro de 13

33. References
Terça-feira, 29 de Janeiro de 13

34. The Metrics Homepage
http://metrics.codahale.com/
Metrics, Metrics, Everywhere - Coda Hale
http://www.youtube.com/watch?v=czes-oa0yik
Graphite
http://graphite.wikidot.com/
References
Terça-feira, 29 de Janeiro de 13

35. Thank you!
@jnelas
joao.nelas@gmail.com
Terça-feira, 29 de Janeiro de 13