Varnish: where developers & sysadmins meet - Varnish Summit Amsterdam 2015

Varnish: where developers & sysadmins meet - Varnish Summit Amsterdam 2015

Transcript

1. Where developers
   & sysadmins meet
   By Thijs Feryn
   Varnish
   

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2. Hi, I’m Thijs
   

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3. I’m
   @ThijsFeryn
   on Twitter
   

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4. I’m an
   Evangelist
   At
   

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5. I’m an
   at
   Evangelist
   

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6. I’m a
   at
   board member
   

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7. Early
   days
   

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8. Down
   

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9. Website performance?
   

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10. More servers
    

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11. Identify slowest part
    

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12. Optimize database
    

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13. Optimize runtime
    

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14. After a while you
    hit the limits
    

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15. Caching
    

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16. Memcached
    or
    Redis
    

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18. Optimize database
    Optimize runtime
    A
    void
    A
    void
    

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19. Varnish
    

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20. Hit rate?
    

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21. Cookies?
    

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22. Cache Control?
    

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23. Developers
    Sysadmins
    

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

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26. Who writes
    the VCL?
    

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27. Varnish still
    considered a
    sysadmin
    responsibility
    

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29. Coaching developers
    & sysadmins
    

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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
    

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

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32. When you respect HTTP
    

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33. Developers
    are bridging
    the gap too
    

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34. Collaboration & empathy
    AKA  DevOps
    

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35. Architecture
    

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36. Service
    Oriented
    Architecture
    

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37. REST
    Cacheable  
    in  Varnish  if  
    done  right
    

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38. Monolith
    vs
    Microservices
    

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39. Distributed
    systems
    

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40. Big Data &
    NoSQL
    

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41. Async,
    concurrent &
    non-blocking
    processing
    

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42. Common goal
    

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43. Better end-user experience
    

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44. Frameworks & CMS’es
    

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46. Bullet
    proof?
    

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47. Well-designed
    software should
    be more scalable
    

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48. Well-designed
    software should
    be faster
    

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

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50. Always cache
    … when you can
    

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

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

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53. Challenges
    

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54. Caching state of mind
    

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55. Purging
    

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

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57. SSL termination
    +  SSL  
    awareness  in  
    application
    

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58. Static assets
    To  
    cache  or  not  
    to  cache?
    Invalidate  
    or  not?
    

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59. Clustering & HA
    

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60. Varnish flow
    

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