Scalability Issues ... cure first, prevent later

Slides for the DPC12 edition of my scalability talk.

Transcript

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2. Evangelist
   

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6. @ThijsFeryn
   

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7. Please3
   rate3my3talk3on3
   Joind.in
   https://joind.in/6247
   

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8. It3works3on3my3computer
   

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10. It’s3the3internet’s3fault
    

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11. Suits
    &
    hipsters
    

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12. “Isn't'hos*ng'
    supposed'to'be'a'
    bulk'product?”
    

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13. “The'Cloud'will'
    make'sure'my'app'
    scales”
    

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14. “Large'campaigns'
    on'shared'hos*ng,'
    why'is'that'a'
    problem?”
    

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15. “What's'a'
    database'index?”
    

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16. “We'll'solve'that'
    with'an'Ajax'call”
    

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17. “We'll'probably'have'
    10.000'visitors'on'
    the'next'campaign”
    

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18. GeBng3the3numbers3right
    

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19. Let’s3do3a3complete3rewrite3!
    

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20. Have3you3got3the3Gme?
    

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21. Or3the3money?
    

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22. What3do3you3do?
    

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23. Nothing
    

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24. Throw3
    servers3at3
    the3
    problem
    

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25. Do3some3
    tricks3!
    

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26. Throw3servers3at3the3problem
    

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27. Scale3verGcally
    

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28. Fast
    Cheap
    vs
    Limited
    Expensive
    Long%
    term
    Short%
    term
    

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29. Scale3horizontally
    

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30. Efficient
    Unlimited
    vs
    ConsideraGons
    IniGal3effort
    Long%
    term
    Short%
    term
    

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31. What3kind3of3infrastructure3do3you3need?
    

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32. What3kind3of3infrastructure3do3you3need?
    One3big3
    box?
    

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33. What3kind3of3infrastructure3do3you3need?
    Scale3across3
    1003nodes?
    

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34. What3kind3of3infrastructure3do3you3need?
    That3big3F53
    loadbalancer?
    

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35. What3kind3of3infrastructure3do3you3need?
    Only3the3DB3
    gets3
    hammered
    

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36. What3kind3of3infrastructure3do3you3need?
    Lots3of3staGc3
    traffic
    

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37. What3kind3of3infrastructure3do3you3need?
    Shared3hosGng3
    will3do3...3
    except3during3the3
    month3of3the3event
    

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38. About3a3mulGYserver3setup
    

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39. Goal:3(almost)3no3code3changes
    

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40. Cache
    

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41. Frontend Backend
    Data%
    cache
    Opcode%
    cache
    Page%
    cache
    APC
    Memcached
    SQLite
    File
    Redis
    +more
    +more
    

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42. What?
    When3not?
    How3long?
    CompaGbility
    Limited3size
    

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43. Tricks
    

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44. RewriteEngine*On
    RewriteCond*%{REQUEST_FILENAME}*=s*[OR]
    RewriteCond*%{REQUEST_FILENAME}*=l*[OR]
    RewriteCond*%{REQUEST_FILENAME}*=d
    RewriteRule*^.*$*=*[NC,L]
    RewriteRule*^.*$*index.php*[NC,L]
    Use3mod_rewrite
    Hit3frontcontroller3if3resource3doesn’t3exist
    

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45. Use3mod_rewrite
    Write3output3to3file3and3print3to3screen
    require('db.php');
    $data = db_get_content_from_uri(
    $_SERVER['REQUEST_URI']);
    $fp = fopen(dirname(__FILE__).
    $_SERVER['REQUEST_URI'], 'w');
    fwrite($fp, $data);
    fclose($fp);
    echo $data;
    

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46. APC
    

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47. Auto3prepend3&3auto3append
    AutomaGcally3executed3before3every3request
    [PHP]
    auto_prepend_file*“/path/to/prepend.php”
    auto_append_file*“/path/to/append.php”
    

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48. Auto3prepend
    Read3from3cache3or3start3output3buffer
    if($_SERVER['REQUEST_METHOD'] == 'GET'){
    $key = md5('http://'.$_SERVER['HTTP_HOST'].
    $_SERVER['REQUEST_URI']);
    if(($output = apc_fetch($key)) !== false){
    echo $output;
    exit();
    }
    ob_start();
    }
    

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49. Auto3append
    Close3output3buffer,3store3data3in3cache3&3
    print3output
    if($_SERVER['REQUEST_METHOD'] == 'GET'){
    $output = ob_get_contents();
    ob_end_clean();
    $key = md5('http://'.$_SERVER['HTTP_HOST'].
    $_SERVER['REQUEST_URI']);
    apc_store($key,$output,20);
    echo $output;
    }
    

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50. Data3cache
    Caching3layer3
    before3on3top3
    of3the3
    database
    

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51. class Data
    {
    private $_mysqlDependency;
    public function __construct($mysqlDependency)
    {
    $this->_mysqlDependency = $mysqlDependency;
    }
    public function fetchQueryFromDatabase($key)
    {
    return $this->_mysqlDependency-
    >fetchQueryEscaped("SELECT * FROM `myTable` WHERE `myKey`
    = '%s'",$key);
    }
    }
    No%
    cache
    

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52. class Data
    {
    private $_namespace = 'myNamespace_';
    private $_ttl = 3600;
    private $_mysqlDependency;
    public function __construct($mysqlDependency)
    {
    $this->_mysqlDependency = $mysqlDependency;
    }
    public function fetchQueryFromDatabase($key)
    {
    if(($value = apc_fetch(md5(
    $this->_namespace.$key))) === false){
    $value = $this->_fetchDataFromDatabase($key);
    $this->_storeDataInCache($key,$value);
    }
    return $value;
    }
    ...
    Override%
    &%use%cache
    Read%
    from%DB%&%
    store%in%cache
    

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53. ...
    private function _storeDataInCache($key,$value)
    {
    apc_store(md5($this->_namespace.$key),$value,
    $this->_ttl);
    return $this;
    }
    private function _fetchQueryFromDatabase($key)
    {
    return $this->_mysqlDependency-
    >fetchQueryEscaped("SELECT * FROM `myTable` WHERE `myKey`
    = '%s'",$key);
    }
    } Fetch%
    from%DB
    Store%
    in%cache
    

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54. You3can3also3use3Memcached
    

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55. You3can3also3use3Memcached
    memcached.sess_prefix = "memc.sess.key."
    session.save_path="127.0.0.1:11211"
    session.save_handler = memcached
    Also%
    for%session%
    handling
    

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56. Reverse3
    (caching)3
    proxies
    

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57. Put3‘em3in3
    front3of3your3
    webserver
    

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58. They3honor3
    your3caching3
    headers
    

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60. Request vcl_recv
    In cache?
    vcl_hash Cacheable?
    vcl_hit() vcl_miss()
    vcl_deliver()
    vcl_fetch()
    No
    Yes
    No
    Yes
    Response
    

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61. backend default {
    .host = "127.0.0.1";
    .port = "8080";
    }
    acl purge {
    "localhost";
    "127.0.0.1";
    "some.host.name.com";
    "1.2.3.4";
    }
    

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62. sub vcl_recv {
    if (req.request == "PURGE") {
    if (!client.ip ~ purge) {
    error 405 "Not allowed: " + client.ip;
    }
    return(lookup);
    }
    if (req.request != "GET" &&
    req.request != "HEAD" &&
    req.request != "PUT" &&
    req.request != "POST" &&
    req.request != "TRACE" &&
    req.request != "OPTIONS" &&
    req.request != "DELETE") {
    return (pipe);
    }
    

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63. if (req.request != "GET" && req.request != "HEAD") {
    return (pass);
    }
    if (req.http.Accept-Encoding) {
    if (req.url ~ "\.(gif|jpg|jpeg|swf|flv|mp3|mp4|
    pdf|ico|png|gz|tgz|bz2)(\?.*|)$") {
    remove req.http.Accept-Encoding;
    } else if (req.http.Accept-Encoding ~ "gzip") {
    set req.http.Accept-Encoding = "gzip";
    } else if (req.http.Accept-Encoding ~ "deflate"){
    set req.http.Accept-Encoding = "deflate";
    } else {
    remove req.http.Accept-Encoding;
    }
    }
    

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64. if (req.url ~ "\.(gif|jpg|jpeg|swf|css|js|flv|mp3|
    mp4|pdf|ico|png)(\?.*|)$") {
    unset req.http.cookie;
    set req.url = regsub(req.url, "\?.*$", "");
    return (lookup);
    }
    if (req.url ~ "\?(utm_(campaign|medium|source|term)|
    adParams|client|cx|eid|fbid|feed|ref(id|src)?|v(er|
    iew))=") {
    set req.url = regsub(req.url, "\?.*$", "");
    }
    if (req.http.cookie ~ "^ *$") {
    unset req.http.cookie;
    }
    

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65. sub vcl_fetch {
    if (req.url ~ "wp-(login|admin)" || req.url ~
    "preview=true" || req.url ~ "xmlrpc.php") {
    return (hit_for_pass);
    }
    if ( (!(req.url ~ "(wp-(login|admin)|login)"))) {
    unset beresp.http.set-cookie;
    set beresp.ttl = 1h;
    }
    if (req.url ~ "\.(gif|jpg|jpeg|swf|css|js|flv|mp3|
    mp4|pdf|ico|png)(\?.*|)$") {
    set beresp.ttl = 365d;
    }
    }
    

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66. sub vcl_deliver {
    if (obj.hits > 0) {
    set resp.http.X-Cache = "HIT";
    } else {
    set resp.http.X-Cache = "MISS";
    }
    }
    sub vcl_hit {
    if (req.request == "PURGE") {
    purge;
    set obj.ttl = 0s;
    error 200 "OK";
    }
    }
    sub vcl_miss {
    if (req.request == "PURGE") {
    purge;
    error 200 "OK";
    }
    }
    

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67. FPM
    hfp://www.php.net/manual/en/install.fpm.configuraGon.php
    

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68. [www]
    listen = 9000
    user = www-data
    group = www-data
    pm = dynamic
    pm.max_children = 10
    pm.start_servers = 4
    pm.max_spare_servers = 6
    pm.max_requests = 500
    php_admin_value[sendmail_path] = /usr/sbin/sendmail -t -i -f
    www@my.domain.com
    php_flag[display_errors] = off
    php_admin_value[error_log] = /var/log/fpm-php.www.log
    php_admin_flag[log_errors] = on
    php_admin_value[memory_limit] = 32M
    

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70. upstream fpm {
    server php1.server.com:9000;
    server php2.server.com:9000;
    }
    upstream memcached {
    server memcached1.server.com:11211;
    server memcached2.server.com:11211;
    }
    server {
    root /var/www;
    index index.php index.html index.htm;
    server_name nginx.server.com;
    location / {
    try_files $uri $uri/ /index.php;
    }
    location @php {
    fastcgi_pass fpm;
    fastcgi_index index.php;
    include fastcgi_params;
    }
    

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71. location ~ \.php$ {
    set $memcached_key $request_uri;
    memcached_pass memcached;
    memcached_next_upstream not_found;
    default_type text/html;
    error_page 404 405 502 = @php;
    }
    location ~* \.(?:ico|css|js|gif|jpe?g|png)$ {
    expires max;
    add_header Pragma public;
    add_header Cache-Control "public, must-
    revalidate, proxy-revalidate";
    }
    }
    

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72. location ~ \.php$ {
    set $memcached_key $request_uri;
    memcached_pass memcached;
    memcached_next_upstream not_found;
    default_type text/html;
    error_page 404 405 502 = @php;
    }
    location ~* \.(?:ico|css|js|gif|jpe?g|png)$ {
    expires max;
    add_header Pragma public;
    add_header Cache-Control "public, must-
    revalidate, proxy-revalidate";
    }
    }
    

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74. Content
    Delivery
    Network
    

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75. +3
    W33Total3
    Cache
    

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77. ✓Enable3caching
    ✓Enable3cron.php
    ✓Configure3log3retenGon
    ✓Flat3catalog
    ✓Enable3compilaGon
    ✓Install3Varnish3Cache3plugin
    ✓Split3frontend3&3backend3servers
    ✓Perform3indexing3on3separate3
    server
    

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79. Boost
    Varnish
    Memcached
    

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80. Don’t3be3clueless
    

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81. Ask3for3help
    

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82. Apply3the3tricks
    

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83. And3don’t3forget3to3refactor3akerwards
    

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84. And3then3relax3...3and3be3happy
    

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