evolving-archetecture4052

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Slide 1: Evolving architecture make development easy and your site faster Leo Lapworth @ YAPC::EU 2007 http://leo.cuckoo.org/ Slide 2: Covering Slide 3: Covering How running websites has evolved Slide 4: Covering How running websites has evolved Servers improved Slide 5: Covering How running websites has evolved Servers improved Architecture improved Slide 6: Covering How running websites has evolved Servers improved Architecture improved Development tools improved Slide 7: Covering How running websites has evolved Servers improved Architecture improved Development tools improved Code (and code libraries) got better Slide 8: but not... Slide 9: but not... Covering anything in depth Slide 10: Concepts stolen from Slide 11: Concepts stolen from Mod_perl guide Slide 12: Concepts stolen from Mod_perl guide Léon Brocard Slide 13: Concepts stolen from Mod_perl guide Léon Brocard Six Apart Slide 14: Concepts stolen from Mod_perl guide Léon Brocard Six Apart Yahoo! Slide 15: Concepts stolen from Mod_perl guide Léon Brocard Six Apart Yahoo! + many other people... Slide 16: Concepts stolen from Mod_perl guide Léon Brocard Six Apart Yahoo! + many other people... ... this is social Perl Slide 17: Templates Slide 18: Templates An example of how things have improved... Slide 19: Recognise this? Slide 20: Recognise this? use CGI; $q = CGI->new(); $name = $q->param('name'); print $q->header('text/html'); $link = 'http://foo.com/'; print "<html><head><title>HTML and code together</title></head><body>"; print "<a href=\"$link/$name\">"; print "Click here $name</a><br />\n"; print "<table>" . join("\n", map { "<tr><td>$_</td></tr>" } qw(this is hard to maintain)); print "</table>"; Slide 21: How about... Slide 22: How about... Now, was it cellspacing, or cellpadding I need for ie4.02? Slide 23: and... Slide 24: and... I'm a developer, not a designer. I shouldn't have to know this £@$%! Slide 25: Use templates... Slide 26: Use templates... use Template; Slide 27: Code, not HTML Slide 28: Code, not HTML use CGI; use Template; $q = CGI->new(); print $q->header('text/html'); my %vals = ( name = $q->param('name'), ); $template = Template->new({ INCLUDE => '/path/' }); $template->process('hello.html',\%vals); Slide 29: I just code, I have clean code and I don't have to know HTML or browser compatibility issues Slide 30: Simple changes make a huge difference Slide 31: Servers Slide 32: Single server Slide 33: Single server Internet Web server (static & dynamic) Database server All editing Slide 34: Lots of... Slide 35: and... I thought I only changed one thing, but it's still broken Slide 36: 1 live server 1 development server Slide 37: 1 live server 1 development server Internet Live server Web server (static & dynamic) Database server Development server Web server (static & dynamic) Database server All editing Slide 38: Does not solve: What did I change last? Who changed what / when? Slide 39: You need... Slide 40: You need... Slide 41: Version control & docs Slide 42: Version control & docs Use SVK with Subversion Slide 43: Version control & docs Use SVK with Subversion Slide 44: Version control & docs Use SVK with Subversion Clkao - SVK Slide 45: Version control & docs Use SVK with Subversion Use Trac (http://trac.edgewall.org) Clkao - SVK Slide 46: Version control & docs Use SVK with Subversion Use Trac (http://trac.edgewall.org) - wiki Clkao - SVK Slide 47: Version control & docs Use SVK with Subversion Use Trac (http://trac.edgewall.org) - wiki - task tracker Clkao - SVK Slide 48: Version control & docs Use SVK with Subversion Use Trac (http://trac.edgewall.org) - wiki - task tracker - web interface to Subversion Clkao - SVK Slide 50: Tests - all you need on one slide Slide 51: Tests - all you need on one slide Write tests, write tests often Slide 52: Tests - all you need on one slide Write tests, write tests often Run tests, run tests often Slide 53: Tests - all you need on one slide Write tests, write tests often Run tests, run tests often Tests are good Slide 54: Tests - all you need on one slide Write tests, write tests often Run tests, run tests often Tests are good Found a bug? - write the test that replicates it. You know it's ﬁxed when your test passes Slide 55: Tests - all you need on one slide Write tests, write tests often Run tests, run tests often Tests are good Found a bug? - write the test that replicates it. You know it's ﬁxed when your test passes Use Test::More, and then test some more! Slide 56: Making your site faster Slide 57: mod_perl Slide 58: mod_perl Code caching (loaded/compiled once) Slide 59: mod_perl Code caching (loaded/compiled once) Server only spends time running the code Slide 60: mod_perl Code caching (loaded/compiled once) Server only spends time running the code Apache::Registry for old/existing code Slide 61: mod_perl Code caching (loaded/compiled once) Server only spends time running the code Apache::Registry for old/existing code Apache::SizeLimit (safety net) Slide 62: mod_perl Code caching (loaded/compiled once) Server only spends time running the code Apache::Registry for old/existing code Apache::SizeLimit (safety net) Set it high Slide 63: mod_perl Code caching (loaded/compiled once) Server only spends time running the code Apache::Registry for old/existing code Apache::SizeLimit (safety net) Set it high Check it Slide 64: Front/back end split Slide 65: Front/back end split Internet Slow Front end Web server (static & proxy to application server) Fast Web server (dynamic) Database server Development server Back end (application server) Slide 66: or put another way... Slide 67: or put another way... Internet slow and demanding kids (users) Slide 68: or put another way... Canteen Internet slow and demanding kids (users) Front end Dinner-ladies - good at serving precooked (static) food. Can order from à la carte chefs and then serve Slide 69: or put another way... Canteen Kitchen Internet slow and demanding kids (users) Front end Dinner-ladies - good at serving precooked (static) food. Can order from à la carte chefs and then serve Back end Chefs - good at making à la carte (dynamic) food Slide 70: Internet Slow Front end Web server (static & proxy to application server) Fast Web server (dynamic) Database server Development server Back end (application server) Slide 71: Internet Slow Front end Web server (static & proxy to application server) Fast Web server (dynamic) Database server Development server Back end (application server) Slide 72: Speed up the frequent... Slide 73: Speed up the frequent... Are you re-creating the same objects/data structures again and again? Slide 74: Speed up the frequent... Are you re-creating the same objects/data structures again and again? Can this information persist for a period of time? Slide 75: Add caching Slide 76: Add caching Persisting data for a period of time Slide 77: Add caching Persisting data for a period of time Simple to implement: Slide 78: Add caching Persisting data for a period of time Simple to implement: Does cache exist? Slide 79: Add caching Persisting data for a period of time Simple to implement: Does cache exist? YES -> retrieve it and return it Slide 80: Add caching Persisting data for a period of time Simple to implement: Does cache exist? YES -> retrieve it and return it NO -> create data/object, store in cache and return it Slide 81: Things you might cache Slide 82: Things you might cache Search result sets (a list of ids) Slide 83: Things you might cache Search result sets (a list of ids) Individual items Slide 84: Things you might cache Search result sets (a list of ids) Individual items Look-ups of information from a database Slide 85: Things you might cache Search result sets (a list of ids) Individual items Look-ups of information from a database Fetching of information from external sources Slide 86: Centralise Slide 87: Centralise Put caching methods in one package Slide 88: Centralise Put caching methods in one package Put any generic methods in a package Slide 89: We now have a cache Internet Slow Front end Web server (static & proxy to application server) Fast Web server (dynamic) Cache Back end (application server) Database server Development server Slide 90: We now have a cache Internet Slow Front end Web server (static & proxy to application server) Fast Web server Cache Cache (dynamic) Database server Development server Back end (application server) Slide 91: Adding in the cache... Slide 92: Adding in the cache... Internet Kids Slide 93: Adding in the cache... Internet Kids Front end Dinner-ladies Slide 94: Adding in the cache... Internet Kids Front end Dinner-ladies Back end Chefs Slide 95: Adding in the cache... Internet Kids Front end Dinner-ladies Back end Chefs Cache Magic freezer Slide 96: Coping with more trafﬁc Slide 97: Coping with more trafﬁc Internet Stage server Development server (in the ofﬁce) Front end Web server (static & proxy to application server) Back end (application server) Web server (dynamic) Back end (application server) Web server (dynamic) Database server Slide 98: Coping with more trafﬁc Internet Stage server Development server (in the ofﬁce) Front end Web server (static & proxy to application server) Back end (application server) Web server (dynamic) Back end (application server) Web server (dynamic) Database server Slide 99: That's two separate disks Slide 100: That's two separate disks Internet Stage server Development server (in the ofﬁce) Front end Web server (static & proxy to application server) Back end (application server) Web server (dynamic) Cache Database server Back end (application server) Web server (dynamic) Cache Slide 101: Second kitchen, two freezers... Slide 102: Second kitchen, two freezers... Internet Kids Slide 103: Second kitchen, two freezers... Internet Kids Front end Dinner-ladies Slide 104: Second kitchen, two freezers... Kitchen 1 Kitchen 2 Internet Kids Front end Dinner-ladies Back end Chefs Slide 105: Second kitchen, two freezers... Kitchen 1 Kitchen 2 Internet Kids Front end Dinner-ladies Back end Chefs Cache Freezers Slide 106: We want a cache across servers... Slide 107: We want a cache across servers... Enter Memcache Slide 108: We want a cache across servers... Enter Memcache See Léon Brocard's talk at 16:20 for the details Slide 109: Internet Stage server Development server (in the ofﬁce) Front end Web server (static & proxy to application server) Back end (application server) Web server (dynamic) Cache Database server Back end (application server) Web server (dynamic) Slide 110: Shared freezer Slide 111: Shared freezer Internet Kids Slide 112: Shared freezer Internet Kids Front end Dinner-ladies Slide 113: Shared freezer Kitchen 1 Kitchen 2 Internet Kids Front end Dinner-ladies Back end Chefs Slide 114: Shared freezer Kitchen 1 Kitchen 2 Internet Kids Front end Dinner-ladies Back end Chefs Cache Freezer Slide 115: Maintaining servers Slide 116: Maintaining servers Keep all servers identical where possible Slide 117: Maintaining servers Keep all servers identical where possible Package your code (e.g. .debs) Slide 118: Maintaining servers Keep all servers identical where possible Package your code (e.g. .debs) Centralise your crontabs and conﬁguration ﬁles (and put in version control) Slide 119: Maintaining servers Keep all servers identical where possible Package your code (e.g. .debs) Centralise your crontabs and conﬁguration ﬁles (and put in version control) Deploy with one script: rsync + ssh + apt-get update & apt-get upgrade (or your OS equivalent) to each server Slide 120: Simplify further Internet Stage server Development server (in the ofﬁce) Front end Perlbal load balancer / proxy Back end Web server (static+dynamic) Cache Database server Back end Web server (static+dynamic) Slide 121: Simplify further Internet Stage server Development server (in the ofﬁce) Front end Perlbal load balancer / proxy Back end Web server (static+dynamic) Cache Database server Back end Web server (static+dynamic) Slide 122: Simplify further Internet Stage server Development server (in the ofﬁce) Front end Perlbal load balancer / proxy Back end Web server (static+dynamic) Cache Database server Back end Web server (static+dynamic) Slide 123: Waiters: cheaper, faster and less demanding Slide 124: Waiters: cheaper, faster and less demanding Internet Kids Slide 125: Waiters: cheaper, faster and less demanding Internet Kids Front end Waiters - good at serving quickly and dealing with annoying customers or Kitchens Slide 126: Waiters: cheaper, faster and less demanding Kitchen 1 Kitchen 2 Internet Kids Front end Waiters - good at serving Back end quickly and dealing with annoying customers or Chefs - simple and complex meals (static and dynamic) Kitchens Slide 127: Waiters: cheaper, faster and less demanding Kitchen 1 Kitchen 2 Internet Kids Front end Waiters - good at serving Back end quickly and dealing with annoying customers or Chefs - simple and complex meals (static and dynamic) Kitchens Cache Freezer Slide 128: More tips for faster user experience Slide 129: mod_gzip Slide 130: mod_gzip HTML/css/xml Slide 131: mod_gzip HTML/css/xml Slide 132: mod_gzip HTML/css/xml gzip Slide 133: mod_gzip HTML/css/xml gzip Slide 134: mod_gzip HTML/css/xml gzip Users Slide 135: mod_gzip HTML/css/xml gzip Users If a browser support compressions... compress (javascript can be tricky - at least minify) Slide 136: Cache headers (expiry) Slide 137: Cache headers (expiry) Slide 138: Cache headers (expiry) Let web browsers know how long to cache Slide 139: Cache somethings forever Slide 140: Cache somethings forever /includes/js/<VERSION>/common.js Slide 141: Cache somethings forever /includes/js/<VERSION>/common.js Ensures user has version which matches HTML (client could have cache of old HTML) Slide 142: Cache somethings forever /includes/js/<VERSION>/common.js Ensures user has version which matches HTML (client could have cache of old HTML) Use include ﬁle to update all pages Slide 143: Handling images: MogileFS Slide 144: Handling images: MogileFS Store images by group (replication levels) Slide 145: Handling images: MogileFS Store images by group (replication levels) Spread IO across disks & servers Slide 146: Handling images: MogileFS Store images by group (replication levels) Spread IO across disks & servers Retrieve from fastest server Slide 147: Handling images: MogileFS Store images by group (replication levels) Spread IO across disks & servers Retrieve from fastest server Integrate with Perlbal, hidden from the user Slide 148: Handling images: MogileFS Store images by group (replication levels) Spread IO across disks & servers Retrieve from fastest server Integrate with Perlbal, hidden from the user Automatic resilience Slide 149: Handling images: MogileFS Store images by group (replication levels) Spread IO across disks & servers Retrieve from fastest server Integrate with Perlbal, hidden from the user Automatic resilience Slide 150: Basic rules to consider