Surprise! Your app is slow because the speed of light is slow.

Ignite talk at Mobile Delivery Days 2016.

Transcript

1. Surprise! Your app is slow
   because the speed of light.
   Clay Smith, New Relic
   @smithclay
   Mobile Delivery Days 2016
   CC0 wikimedia.org
   

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2. When you release an
   app...
   CC0 pixabay.com
   

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3. When you get a review
   like this...
   "App slow in the UK. 1 star."
   -BenedictC
   CC0 pixabay.com
   

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4. Who owns mobile app
   network issues?
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   Backend/Ops
   Device/
   Mobile Devs
   "Stuff in the middle we don't control"
   

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5. Mobile data growth
   (simplified)
   Amount of data
   Now In a couple years
   

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6. Global Network
   Latency in Fiber
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   Source Destination
   Great Circle
   Distance
   RT Time in
   Fiber
   SFO London 5,375 mi 84 ms
   SFO Cape Town 10,124 mi 158 ms
   1 ms at speed of light = Length of Massachusetts
   

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7. After one second, your
   flow of thought is interrupted.
   CC0 pixabay.com
   Milliseconds
   1
   10
   100
   1000
   10000
   Not Magic Interrupted Too Late
   https://www.nngroup.com/articles/response-times-3-important-limits/
   

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8. App services: more cloud,
   more complexity
   CC0 openclipart.org
   REST API
   Auth - IdP #1
   Analytics
   Ad Network
   Auth - IdP #2
   

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9. Move it closer?
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   Datacenter/AZ
   CDN
   

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10. CDNs on the Edge
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    Cache static and dynamic
    content + "uncached origin fetch"
    

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11. #mobileperf Idea
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    When in doubt, reduce the
    number of TCP connections.
    

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12. TCP: Use it again
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    Use HTTP keep-alive to reuse
    TCP connections.
    

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13. TCP: Create connections
    faster
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    TCP Fast Open can speed up
    opening multiple connections.
    

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14. https://blog.newrelic.com/2016/02/09/http2-best-practices-web-performance/
    

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15. Weighing HTTP/2
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    multiplexing,
    compression
    Hard to
    debug,
    backend
    support?
    

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16. What dial do we turn (if any)?
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17. Premature optimization
    is the source of all evil.
    -Donald Knuth in 1974
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    Don't touch that dial.
    (yet)
    

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18. CC0 pixabay.com
    Measure often to
    understand what matters.
    

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19. CC0 pixabay.com
    Measure network
    latency and connect it
    to U/X
    

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20. Building connected mobile
    apps is hard. Monitoring
    shouldn't be.
    Thanks!
    Clay Smith, New Relic
    @smithclay
    Mobile Delivery Days 2016
    CC0 wikimedia.org
    

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