Nowadays web platforms are composed of multiple parts - large applications are surrounded by countless of smaller services and tiny serverless functions. If you’ve ever started a transition from a monolith to more distributed model you know that’s very rarely a big bang. It’s a long process that takes time. You take one feature, extract it to a module and define a clear API, so it can be incorporated easily into a bigger picture that you’re building. Eventually you end up with a complex distributed platform that has to be managed somehow. Deployments, traffic routing, security, reliability - you have to consider all of those aspects in your implementation plan. At the same time you have to keep in mind that even the most sophisticated platform doesn’t provide any value by itself if it doesn’t meet expectations of your end users. During this talk I’d like to present how Cognifide manages platforms composed of many applications, route traffic between smaller components and delivers content to users spread all over the world via Content Delivery Network (CDN).

1. Taming content delivery at scale
Jakub Wądołowski (@jwadolowski)
https://flic.kr/p/qJvJ6u

2. The generic story
https://flic.kr/p/ithHFu
• Banking / insurance / automotive / retail industry
• 100% offline business since the very beginning
• Online presence followed by multi-market expansion

6. Err… now what?
• Will my application handle increased load?
• Should I replicate my stack N times?
• What about end user performance?
https://flic.kr/p/7F4bHa

7. Is there a better way?
https://flic.kr/p/2dtPsCt

8. Content Delivery Network overview
https://flic.kr/p/nmDAHq

12. CDN features
https://flic.kr/p/qKCXMK
• reverse caching proxy
• HTTP routing
• request/response flow control (VCL)
• content assembly (ESI - Edge Side Includes)
• web application firewall (WAF)
• image optimizer
• various L4/L7 optimizations (Brotli, HTTP/2, TLS, BBR, etc)
• edge computing

13. Beating the speed of light
https://flic.kr/p/qN2qzM

20. Sounds fishy?
https://flic.kr/p/aebhfA

23. HTTP routing
https://flic.kr/p/2eQGY86

29. Edge Side Includes
https://flic.kr/p/q3aURH

36. Things go south sometimes…
https://flic.kr/p/7rstvj
• My content is dynamic!
• I use personalisation!
• I need to authenticate to see anything!
• A/B tests!
• …

37. There’s no such things as dynamic content.
Everything is static until it changes.
Tyler McMullen, CTO at Fastly

38. Caching mistake #1
https://flic.kr/p/jkQKNv

39. HTTP/1.1 302 Found
Date: Fri, 09 Aug 2019 09:56:18 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 36538
Connection: keep-alive
Cache-Control: no-cache, no-store, must-revalidate
Location: https://example.com/secure
Server: nginx
Caching mistake #1

40. HTTP/1.1 302 Found
Date: Fri, 09 Aug 2019 09:56:18 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 36538
Connection: keep-alive
Cache-Control: no-cache, no-store, must-revalidate
Location: https://example.com/secure
Server: nginx
Caching mistake #1

41. HTTP/1.1 302 Found
Date: Fri, 09 Aug 2019 09:56:18 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 36538
Connection: keep-alive
Cache-Control: no-cache, no-store, must-revalidate
Location: https://example.com/secure
Server: nginx
Caching mistake #1

42. HTTP/1.1 302 Found
Date: Fri, 09 Aug 2019 09:56:18 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 36538
Connection: keep-alive
Cache-Control: no-cache, no-store, must-revalidate
Location: https://example.com/secure
Server: nginx
Caching mistake #1

43. Caching mistake #2
https://flic.kr/p/j45cS3

44. HTTP/1.1 200 OK
Date: Fri, 09 Aug 2019 09:14:38 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 87112
Connection: keep-alive
Cache-Control: public, no-cache="Set-Cookie", max-age=180
Expires: Fri, 09 Aug 2019 09:17:22 GMT
Last-Modified: Fri, 09 Aug 2019 09:14:22 GMT
Vary: Accept-Encoding
Server: nginx
Caching mistake #2

45. HTTP/1.1 200 OK
Date: Fri, 09 Aug 2019 09:14:38 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 87112
Connection: keep-alive
Cache-Control: public, no-cache="Set-Cookie", max-age=180
Expires: Fri, 09 Aug 2019 09:17:22 GMT
Last-Modified: Fri, 09 Aug 2019 09:14:22 GMT
Vary: Accept-Encoding
Server: nginx
Caching mistake #2

46. In http 1.1, Roy has proposed some features
for the new cache-control directive that
allow servers to selectively disable caching
on specific headers. This would be, for
example:
cache-control: no-cache="set-cookie"
Caching mistake #2

47. Who is Roy?
Caching mistake #2

49. We barely scratched the surface…
https://flic.kr/p/CGmgy3

50. Thank you!
https://flic.kr/p/gq5UAU