Scalability Issues ... cure first, prevent later

Slides for the DPC12 edition of my scalability talk.

Transcript

2. Evangelist
6. @ThijsFeryn
7. Please3 rate3my3talk3on3 Joind.in https://joind.in/6247
8. It3works3on3my3computer
10. It’s3the3internet’s3fault
11. Suits & hipsters
12. “Isn't'hos*ng' supposed'to'be'a' bulk'product?”
13. “The'Cloud'will' make'sure'my'app' scales”
14. “Large'campaigns' on'shared'hos*ng,' why'is'that'a' problem?”
15. “What's'a' database'index?”
16. “We'll'solve'that' with'an'Ajax'call”
17. “We'll'probably'have' 10.000'visitors'on' the'next'campaign”
18. GeBng3the3numbers3right
19. Let’s3do3a3complete3rewrite3!
20. Have3you3got3the3Gme?
21. Or3the3money?
22. What3do3you3do?
23. Nothing
24. Throw3 servers3at3 the3 problem
25. Do3some3 tricks3!
26. Throw3servers3at3the3problem
27. Scale3verGcally
28. Fast Cheap vs Limited Expensive Long% term Short% term
29. Scale3horizontally
30. Efficient Unlimited vs ConsideraGons IniGal3effort Long% term Short% term
31. What3kind3of3infrastructure3do3you3need?
32. What3kind3of3infrastructure3do3you3need? One3big3 box?
33. What3kind3of3infrastructure3do3you3need? Scale3across3 1003nodes?
34. What3kind3of3infrastructure3do3you3need? That3big3F53 loadbalancer?
35. What3kind3of3infrastructure3do3you3need? Only3the3DB3 gets3 hammered
36. What3kind3of3infrastructure3do3you3need? Lots3of3staGc3 traffic
37. What3kind3of3infrastructure3do3you3need? Shared3hosGng3 will3do3...3 except3during3the3 month3of3the3event
38. About3a3mulGYserver3setup
39. Goal:3(almost)3no3code3changes
40. Cache
41. Frontend Backend Data% cache Opcode% cache Page% cache APC Memcached SQLite File Redis +more +more
42. What? When3not? How3long? CompaGbility Limited3size
43. Tricks
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
45. Use3mod_rewrite Write3output3to3file3and3print3to3screen <?php 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 $data;
46. APC
47. Auto3prepend3&3auto3append AutomaGcally3executed3before3every3request [PHP] auto_prepend_file*“/path/to/prepend.php” auto_append_file*“/path/to/append.php”
48. Auto3prepend Read3from3cache3or3start3output3buffer <?php if($_SERVER['REQUEST_METHOD'] == 'GET'){ $key = md5('http://'.$_SERVER['HTTP_HOST']. $_SERVER['REQUEST_URI']); if(($output = apc_fetch($key)) !== false){ echo $output; exit(); } ob_start(); }
49. Auto3append Close3output3buffer,3store3data3in3cache3&3 print3output <?php if($_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; }
50. Data3cache Caching3layer3 before3on3top3 of3the3 database
51. <?php 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
52. <?php 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 $value; } ... Override% &%use%cache Read% from%DB%&% store%in%cache
53. ... private function _storeDataInCache($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
54. You3can3also3use3Memcached
55. You3can3also3use3Memcached memcached.sess_prefix = "memc.sess.key." session.save_path="127.0.0.1:11211" session.save_handler = memcached Also% for%session% handling
56. Reverse3 (caching)3 proxies
57. Put3‘em3in3 front3of3your3 webserver
58. They3honor3 your3caching3 headers
60. Request vcl_recv In cache? vcl_hash Cacheable? vcl_hit() vcl_miss() vcl_deliver() vcl_fetch() No Yes No Yes Response
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"; }
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); }
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)(\?.*|)$") { remove req.http.Accept-Encoding; } else if (req.http.Accept-Encoding ~ "gzip") { set req.http.Accept-Encoding = "gzip"; } else if (req.http.Accept-Encoding ~ "deflate"){ set req.http.Accept-Encoding = "deflate"; } else { remove req.http.Accept-Encoding; } }
64. if (req.url ~ "\.(gif|jpg|jpeg|swf|css|js|flv|mp3| mp4|pdf|ico|png)(\?.*|)$") { 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 ~ "^ *$") { unset req.http.cookie; }
65. sub vcl_fetch { if (req.url ~ "wp-(login|admin)" || req.url ~ "preview=true" || req.url ~ "xmlrpc.php") { return (hit_for_pass); } if ( (!(req.url ~ "(wp-(login|admin)|login)"))) { unset beresp.http.set-cookie; set beresp.ttl = 1h; } if (req.url ~ "\.(gif|jpg|jpeg|swf|css|js|flv|mp3| mp4|pdf|ico|png)(\?.*|)$") { set beresp.ttl = 365d; } }
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"; } }
67. FPM hfp://www.php.net/manual/en/install.fpm.configuraGon.php
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
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 $uri/ /index.php; } location @php { fastcgi_pass fpm; fastcgi_index index.php; include fastcgi_params; }
71. location ~ \.php$ { 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"; } }
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"; } }
74. Content Delivery Network
75. +3 W33Total3 Cache
77. ✓Enable3caching ✓Enable3cron.php ✓Configure3log3retenGon ✓Flat3catalog ✓Enable3compilaGon ✓Install3Varnish3Cache3plugin ✓Split3frontend3&3backend3servers ✓Perform3indexing3on3separate3 server
79. Boost Varnish Memcached
80. Don’t3be3clueless
81. Ask3for3help
82. Apply3the3tricks
83. And3don’t3forget3to3refactor3akerwards
84. And3then3relax3...3and3be3happy