CDN: Caching and edge computing on AWS

Explaining the basis of CDNs and Cloudfront on AWS

Transcript

1. CDN Pierre GOUDJO Caching and Edge Computing
7. Compression
8. TLS Termination Compression
9. TLS Termination Application Firewall Compression
10. TLS Termination Application Firewall Load Balancing Compression
11. TLS Termination Application Firewall Load Balancing Caching Compression
13. HTTP Cache goals
14. ACCELERATE REQUESTS FROM THE INTERNET
15. REDUCING PEAK SERVER LOAD
16. REDUCING NUMBER OF NEEDED APPLICATION NODES
21. Server decides how intermediaries cache the resources
22. • Cache-Control • Etag • Last-Modi fi ed HTTP Headers
23. • public: the response may be stored by any cache. • private: the response may be stored only by a browser's cache • no-cache: the stored response MUST always go through validation with the origin server fi rst before using it • no-store: the response may not be stored in any cache. • no-transform: an intermediate cache or proxy cannot edit the response body • must-revalidate: indicates that once a resource becomes stale, caches must not use their stale copy without successful validation on the origin server. Cache-Control
24. • max-age=<seconds>: the maximum amount of time a resource is considered fresh • max-stale[=<seconds>]: indicates the client will accept a stale response. • min-fresh=<seconds>: indicates the client wants a response that will still be fresh for at least the speci fi ed number of seconds. • stale-while- revalidate=<seconds>: indicates the client will accept a stale response, while asynchronously checking in the background for a fresh one • stale-if-error=<seconds>: indicates the client will accept a stale response if the check for a fresh one fails. Cache-Control
25. ETag
26. Last-Modified: <day-name>, <day> <month> <year> <hour>:<minute>:<second> GMT If-Modified-Since: <day-name>, <day> <month> <year> <hour>:<minute>:<second> GMT Last-Modified
28. Caching is good, but it’s only one part of the story
29. SERVERS FAILURE
33. HIGH TRAFFIC
35. SPEED OF LIGHT: THE HARD LIMIT
38. https://www.cloud fl are.com/en-gb/network/
39. You don’t want to build that yourself 😂
50. Common CDN Offerings • Nearest cache node “routing”: DNS or Anycast • DDoS protection • HTTPS/SSL/TLS encryption and termination • Access Control, geo-restriction • IPv6
51. Drawbacks • No control over cache eviction • Additional point of failure • Privacy and security challenges
53. © Amazon web Services
54. Multi-level caching
55. © Amazon web Services
56. NO REGIONAL LOCATIONS SOMETIMES © Amazon web Services
57. © Amazon web Services
58. How Cloudfront identifies the cached content?
59. The cache key 
 🔑
60. GET /content/stories/example-story.html?ref=0123abc&split-pages=false HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 Gecko/20100101 Firefox/68.0 Accept: text/html,*/* Accept-Language: en-US,en Cookie: session_id=01234abcd Referer: https://news.example.com/
61. GET /content/stories/example-story.html?ref=0123abc&split-pages=false HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 Gecko/20100101 Firefox/68.0 Accept: text/html,*/* Accept-Language: en-US,en Cookie: session_id=01234abcd Referer: https://news.example.com/
62. GET /content/stories/example-story.html?ref=0123abc&split-pages=false HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
63. GET /content/stories/example-story.html?ref=0123abc&split-pages=false HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/ A cache hit
64. GET /content/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
65. GET /content/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/ A cache hit again 🙂
66. Fortunately the cache key components can be tweaked with a cache policy
67. Cache policy • Query String • Cookies • Request headers
68. Cache policy • Query String • Cookies • Request headers You can choose as m uch as 10 for each type
69. GET /content/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
70. GET /content/stories/example-story.html?ref=xyz987&split-pages=false HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
71. GET /content/stories/example-story.html?ref=xyz987&split-pages=false HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/ A cache hit
72. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
73. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/ A cache miss ☹
74. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry Referer: https://news.example.com/
75. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz1234; yummy_cookie=choco; tasty_cookie=strawberry Referer: https://news.example.com/
76. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz1234; yummy_cookie=choco; tasty_cookie=strawberry Referer: https://news.example.com/ A cache miss ☹
77. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=vanilla; tasty_cookie=strawberry Referer: https://news.example.com/
78. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=vanilla; tasty_cookie=strawberry Referer: https://news.example.com/ A cache hit 🎉
79. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry Referer: https://news.example.com/
80. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry Referer: https://site2.example.com/
81. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry Referer: https://site2.example.com/ A cache miss ☹
82. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry referer: https://news.example.com/
83. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry referer: https://news.example.com/ A cache hit 🎉 because Cloudfront doesn’t consider the case of the header name
84. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry referer: HTTPS://NEWS.EXAMPLE.COM/
85. GET /content/stories/example-story.html?ref=xyz1234&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876; yummy_cookie=choco; tasty_cookie=strawberry referer: HTTPS://NEWS.EXAMPLE.COM/ A cache miss ☹ because Cloudfront does consider the case of the header value
86. Cache key selection is a software architecture decision
87. GET /content/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr-FR,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
88. GET /content/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/
89. GET /content/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/ A cache miss ☹ because fr-FR and fr are not the same thing even though they both mean the user language is French
90. GET /content/fr/stories/example-story.html?ref=xyz987&split-pages=true HTTP/1.1 Host: d111111abcdef8.cloudfront.net User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/83.0.4103.116 Accept: text/html,*/* Accept-Language: fr,en Cookie: session_id=wxyz9876 Referer: https://news.example.com/ One of many possible solutions
92. Sometimes bare CDN functionalities are not enough
93. Examples • Real-time image manipulation • Website security and checking • Bot mitigation at the edge • User prioritisation • …
94. Some add some of these functionalities to their catalogue
95. But can’t cover all users custom needs
96. Enter Edge-computing
106. 1ms 5s - 30 s 2MB 128 - 3008 MB
109. Demo Cloudfront Functions
110. Cloudflare architecture
111. Cloudflare architecture
113. Demo Cloudflare Workers