Caching the uncacheable with Varnish - FullstackEU 2019

This talk is about caching personalized data in Varnish by leveraging synthetic HTTP, synthetic backends, Redis and our Edgestash module.

See https://feryn.eu/speaking/caching-uncacheable-varnish/ for more details.

Transcript

1. CACHING THE UNCACHEABLE
   BY THIJS FERYN
   WITH VARNISH
   

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2. Slow websites
   SUCK
   

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3. WEB PERFORMANCE IS AN
   ESSENTIAL PART OF THE
   USER EXPERIENCE
   

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4. SLOW ~ DOWN
   

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8. THROWING
   SERVERS
   AT THE PROBLEM
   

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9. MO' MONEY
   MO' SERVERS
   MO' PROBLEMS
   

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10. IDENTIFY SLOWEST PARTS
    

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11. OPTIMIZE
    

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12. AFTER A WHILE YOU HIT THE LIMITS
    

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13. CACHE
    

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14. HI, I'M THIJS
    

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15. I'M AN
    EVANGELIST
    AT
    

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18. 4,800,000 WEBSITES
    19% OF THE TOP 10K WEBSITES
    

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20. I'M @THIJSFERYN
    

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23. NORMALLY
    USER SERVER
    

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24. WITH REVERSE CACHING PROXY
    USER PROXY SERVER
    

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27. CONTROLLING THE CACHE WITH HTTP
    Expires: Sat, 09 Sep 2017 14:30:00 GMT
    Cache-control: public, max-age=3600, s-maxage=86400
    Cache-control: private, no-cache, no-store
    Vary: Accept-Language
    

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28. STATE
    

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29. STATE
    ~
    USER SPECIFIC DATA
    COOKIES
    AUTH
    HEADERS
    

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30. FOR YOUR EYES ONLY
    NOT CACHED
    

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31. VARNISH CONFIGURATION LANGUAGE
    

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32. vcl 4.1;
    sub vcl_recv {
    if (req.http.Cookie) {
    set req.http.Cookie = ";" + req.http.Cookie;
    set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
    set req.http.Cookie = regsuball(req.http.Cookie,
    ";(SESS[a-z0-9]+|SSESS[a-z0-9]+|NO_CACHE)=", "; \1=");
    set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
    set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
    if (req.http.Cookie == "") {
    unset req.http.Cookie;
    }
    else {
    return (pass);
    }
    }
    }
    Only
    keep certain
    cookies
    

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33. sub vcl_recv {
    if (req.http.Cookie) {
    set req.http.Cookie = ";" + req.http.Cookie;
    set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
    set req.http.Cookie = regsuball(req.http.Cookie, ";(language)=", "; \1=");
    set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
    set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
    if (req.http.cookie ~ "^\s*$") {
    unset req.http.cookie;
    return(pass);
    }
    return(hash);
    }
    }
    sub vcl_hash {
    hash_data(regsub( req.http.Cookie, "^.*language=([^;]*);*.*$", "\1" ));
    }
    Cookie
    cache
    variation
    

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34. vcl 4.1;
    import cookieplus;
    sub vcl_recv {
    cookieplus.keep("language");
    cookieplus.write();
    }
    sub vcl_hash {
    hash_data(cookieplus.get("language"));
    }
    VMOD_COOKIE
    

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35. CONTAINS
    USER
    INFORMATION
    

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36. NO CACHE
    

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37. PLACEHOLDERS
    

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38. SEPARATE
    HTTP REQUEST
    

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39. AJAX
    

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40. ✓CLIENT-SIDE
    ✓COMMON KNOWLEDGE
    ✓PARALLEL PROCESSING
    ✓GRACEFUL
    DEGRADATION
    -PROCESSED BY THE
    BROWSER
    -EXTRA ROUNDTRIPS
    -SOMEWHAT SLOWER
    AJAX
    

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41. EDGE-SIDE INCLUDES ESI
    

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42. 
    

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43. ESI
    ✓ PLACEHOLDER
    ✓ PARSED BY VARNISH
    ✓ OUTPUT IS A COMPOSITION OF BLOCKS
    ✓ STATE PER BLOCK
    ✓ TTL PER BLOCK
    

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44. sub vcl_recv {
    set req.http.Surrogate-Capability = "key=ESI/1.0";
    }
    sub vcl_backend_response {
    if (beresp.http.Surrogate-Control ~ "ESI/1.0") {
    unset beresp.http.Surrogate-Control;
    set beresp.do_esi = true;
    }
    }
    

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45. ✓SERVER-SIDE
    ✓STANDARDIZED
    ✓PROCESSED ON THE
    “EDGE”, NOT IN THE
    BROWSER
    ✓GENERALLY FASTER
    -SEQUENTIAL*
    -ONE FAILS, ALL FAIL
    -LIMITED
    IMPLEMENTATION IN
    VARNISH
    -NOT THAT COMMON
    ESI PARALLEL IN
    ENTERPRISE
    

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46. NON-CACHEABLE ROUTES WILL STILL BE A
    TARGET FOR LOAD/LATENCY
    

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47. NOT JUST A CACHE
    NOT JUST "TAKE IT OR LEAVE IT"
    

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48. AN HTTP
    LOGIC BOX
    

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49. DECISION MAKING AT THE EDGE
    

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50. vcl 4.1;
    import cookieplus;
    import redis;
    import synthbackend;
    sub vcl_init
    {
    new db = redis.db(
    location="redis:6379",
    type=master,
    connection_timeout=500,
    shared_connections=false,
    max_connections=1);
    }
    sub vcl_recv
    {
    set req.http.X-Login = "false";
    set req.http.x-session = cookieplus.get("PHPSESSID","guest");
    if(req.http.x-session != "guest") {
    db.command("EXISTS");
    db.push("sf_s"+cookieplus.get("PHPSESSID"));
    db.execute();
    if(db.get_integer_reply() == 1) {
    set req.http.X-Login = "true";
    }
    }
    }
    SYNTHETIC HTTP
    

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51. sub vcl_backend_fetch
    {
    if(bereq.url == "/session") {
    if(bereq.http.X-Login != "true") {
    set bereq.backend = synthbackend.from_string("{}");
    return(fetch);
    }
    db.command("EVAL");
    db.push({"
    local session = redis.call('GET', KEYS[1])
    if session == nil then
    return '{}'
    end
    local result = string.gsub(session, '[%c]', '')
    local username = string.gsub(result,'.+Userusername\";s:[0-9]+:\"([^\"]+)\";.+','%1')
    if username == nil then
    return '{}'
    end
    return '{"username":"'.. username ..'"}'
    "});
    db.push(1);
    db.push("sf_s"+cookieplus.get("PHPSESSID"));
    db.execute();
    set bereq.backend = synthbackend.from_string(db.get_string_reply());
    }
    }
    sub vcl_backend_response
    {
    if(bereq.url == "/session") {
    set beresp.http.Content-Type = "application/json; charset=utf-8";
    set beresp.ttl = 3600s;
    set beresp.http.vary = "x-session";
    }
    }
    REDIS LUA
    CODE
    

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52. USER
    GET /session
    Cookie: PHPSESSID=7er3hjKal8u235c87u6ih0vz8Y
    HTTP/1.1 200 OK
    Content-Length: 31
    Content-Type: application/json; charset=utf-8
    X-Varnish: 163854 196622
    Age: 27
    {"username":"thijs"}
    VARNISH
    

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53. WHAT DO YOU DO WITH IT?
    ✓ AJAX CALL
    ✓ LOAD VIA ESI AND PROCESS VIA LOCAL JAVASCRIPT
    ✓ EDGESTASH
    

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54. {{ EDGESTASH }}
    VARNISH
    MODULE FOR MUSTACHE
    PROCESSING ON THE
    EDGE
    

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55. vcl 4.1;
    import edgestash;
    backend default
    {
    .host = "1.1.1.1";
    .port = "80";
    }
    sub vcl_backend_response {
    if (bereq.url == "/session") {
    edgestash.index_json();
    } else if (bereq.url == "/") {
    edgestash.parse_response();
    }
    }
    sub vcl_deliver {
    if (req.url == "/" && edgestash.is_edgestash()) {
    edgestash.add_json_url("/session");
    edgestash.execute();
    }
    }
    EDGESTASH
    

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56. EDGESTASH
    {"username":"Thijs"}
    {{ username }}
    Thijs
    

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57. MORE FLEXIBILITY
    

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58. Surrogate-Control: edgestash="EDGESTASH/2.1"
    Link: ; rel=edgestash
    

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59. vcl 4.1;
    import edgestash;
    import std;
    backend default
    {
    .host = "1.1.1.1";
    }
    sub vcl_recv
    {
    set req.http.Surrogate-Capability={"edgestash="EDGESTASH/2.1""};
    }
    sub vcl_backend_response
    {
    if(beresp.http.Link) {
    std.collect(beresp.http.Link,",");
    }
    if(beresp.http.Link ~ "<([^>]+)>; rel=edgestash") {
    set beresp.http.x-edgestash-json-urls = regsuball(beresp.http.Link,"(?(?=<[^>]+>; rel=edgestash)<([^>]+)>;
    rel=edgestash|<([^>]+)>; rel=[a-z]+, )","\1");
    }
    if(beresp.http.Surrogate-Control) {
    std.collect(beresp.http.Surrogate-Control);
    }
    if(beresp.http.Surrogate-Control ~ {".*="EDGESTASH/2\.[0-9]+".*"}) {
    edgestash.parse_response();
    }
    }
    EDGESTASH
    

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60. sub vcl_deliver
    {
    if(edgestash.is_edgestash() && resp.http.x-edgestash-json-urls) {
    edgestash.add_json_url_csv(resp.http.x-edgestash-json-urls);
    edgestash.execute();
    }
    unset resp.http.Link;
    unset resp.http.x-edgestash-json-urls;
    unset resp.http.surrogate-control;
    }
    EDGESTASH
    

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62. COMPOSER REQUIRE THIJSFERYN/EDGESTASH-TWIG-BUNDLE
    

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63. {{ edgestash('username','/session') }}
    {{ username | edgestash('username','/session') }}
    

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64. 
    {% if isEdgestash() %}
    //Edgestash-supported logic
    {% else %}
    //Regular Twig logic
    {% endif %}
    
    

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65. {{ edgestash('#username', '/session') }}
    Welcome {{ edgestash('username') }}
    {{ edgestash('/username') }}
    {{ edgestash('^username') }}
    Welcome guest
    {{ edgestash('/username') }
    

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66. 
    {{ edgestash('#.', '/users') }}
    {{ edgestash('username') }}
    {{ edgestash('/.') }}
    
    

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68. FROM $0.20/H + 14 DAYS FREE TRIAL
    

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71. HTTPS://FERYN.EU
    HTTPS://TWITTER.COM/THIJSFERYN
    HTTPS://INSTAGRAM.COM/THIJSFERYN
    

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