Amsterdam summit 2015

1. Where developers
& sysadmins meet
By Thijs Feryn
Varnish

2. Hi, I’m Thijs

3. I’m
@ThijsFeryn
on Twitter

4. I’m an
Evangelist
At

5. I’m an
at
Evangelist

6. I’m a
at
board member

7. Early
days

8. Down

9. Websiteperformance?

10. More servers

11. Identify slowest part

12. Optimize database

13. Optimizeruntime

14. After a while you
hit the limits

15. Caching

16. Memcached
or
Redis

18. Optimizedatabase
Optimizeruntime
Avoid
Avoid

19. Varnish

20. Hitrate?

21. Cookies?

22. CacheControl?

23. Developers
Sysadmins

25. ✓State
✓Performance
✓Scalability
✓Cache invalidation
✓Architecture
People often forget

26. Whowrites
theVCL?

27. Varnishstill
considereda
sysadmin
responsibility

29. Coaching developers
& sysadmins

30. ✓No state unless required
✓Cache-control discipline
✓Chop pages into content
blocks
✓AJAX or ESI
✓Reasonable cache
variations
✓Cache invalidation strategy
Advice for developers

31. ✓Normalize input
✓Cookies blacklist/whitelist
✓URL blacklist/whitelist
VCL

32. Whenyou respectHTTP

33. Developersare bridgingthe gap too

34. Collaboration&empathy
AKA
DevOps

35. Architecture

36. Service
Oriented
Architecture

37. RESTCacheable
in
Varnish
if
done
right

38. Monolith
vs
Microservices

39. Distributed
systems

40. BigData&
NoSQL

41. Async,
concurrent&
non-blocking
processing

42. Commongoal

43. Betterend-userexperience

44. Frameworks&CMS’es

46. Bullet
proof?

47. Well-designed
software should
be more scalable

48. Well-designed
software should
be faster

49. Well-designed
software doesn’t
need much
caching?

50. Alwayscache
…whenyoucan

51. Well-designed
software doesn’t
require much VCL

52. Well-designed
software knows
how to purge the
cache

53. Challenges

54. Cachingstateofmind

55. Purging

56. There are only two hard
things in Computer
Science: cache
invalidation and naming
things.
—- Phil Karlton

57. SSLtermination
+
SSL
awareness
in
application

58. Staticassets
To
cache
or
not
to
cache?
Invalidate
or
not?

59. Clustering&HA

60. Varnishflow