![.htaccessSetup
Redirect login'sto origin site:
# Redirect logins to nonCDN site
RewriteCond %{HTTP_HOST} !^origin.college.edu [NC]
RewriteRule ^user/login$ https://origin.college.edu/user/login [R=301,L]
RewriteCond %{HTTP_HOST} !^origin.college.edu [NC]
RewriteRule ^user$ https://origin.college.edu/user [R=301,L]](https://image.slidesharecdn.com/tridug-cdns-150319164410-conversion-gate01/85/Using-Content-Delivery-Networks-with-Drupal-25-320.jpg)
![Settings.php Setup
Thefollowing codeletstheCDN support HTTPS. Needsto bein
thesettings.php file.
if (isset($_SERVER['HTTP_CLOUDFRONT_FORWARDED_PROTO']) &&
$_SERVER['HTTP_CLOUDFRONT_FORWARDED_PROTO'] == 'https') {
$_SERVER['HTTPS'] = 'on';
$_SERVER['HTTP_X_FORWARDED_PROTO'] = 'https';
}
// The following are only needed if the 'nonCDN' site can be
// accessed by more than 1 host name E.g., initially an internal
// DNS entry and then moved to a client DNS entry.
if ( isset($_SERVER['HTTP_HOST']) &&
$_SERVER['HTTP_HOST'] == 'collegeorigin.longsight.com') {
$_SERVER['HTTP_HOST'] = 'origin.college.edu';
}](https://image.slidesharecdn.com/tridug-cdns-150319164410-conversion-gate01/85/Using-Content-Delivery-Networks-with-Drupal-27-320.jpg)
Using Content Delivery Networks with Drupal
- 1. Using Content Delivery Networks with Drupal TriDUG – March 2015
- 2. What areCDNs A content delivery network or content distribution network (CDN) isalarge distributed system of serversdeployed in multipledatacentersacrossthe Internet. Thegoal of aCDN isto servecontent to end-userswith high availability and high performance.
- 3. Traditional Delivery Theserver in theimage representseither a singleserver or asingle datacenter with aproxy front end (e.g. Varnish / nGinx )
- 4. CDN Delivery Theseserversrepresent different datacenters that can belocated in different areasof the world. Clientsget served information from the best site.
- 5. Why UseaCDN ● Increasethenumber of usersthat can accessthesite without degradation. ● Ensurequality user experienceby having all or parts of apageloaded from serverscloseto them ● Lower theimpact of usersaccessing largefiles
- 6. CDN Basics ● Theterm origin refersto thesourceserver ● CDN clustersinstancesaredefined by aspecial DNS host name, e.g. <dist id>.cloudfront.net ● TheCDN'sDNSentry will berouted thru an (expensive) load balancing routing system that determinesthebest server to servicetherequest. ● DNSsettingsand URL rewriting areused to cause clientsto get theinformation from thecluster. ● Filescached on theCDN all have“expiration” times that can beset/controlled in variousmanners.
- 7. Anatomy of A CDN Request ● Client browser requestsaCDN cached fileviaan embedded URL or just entering theURL. ● TheCDN'sload balancing routerswill determinetheCDN server to usebased on clientslocation, etc. ● TheCDN server selected looksto seeif thisfileexists. ● If thefileexists, it checksthe“expiration” date. ● If thefileexistsand hasnot expired, it returnsthecache version. Theorigin server doesno work. ● Otherwise, if possible, theCDN will ask theorigin server for afresh copy of thefileand send it to theclient.
- 8. CDN Services ● Akamai Technologies ● Amazon CloudFront ● WindowsAzureCDN ● EdgeCast Networks ● RackspaceCloud Files ● Vimeo ● YouTube ● ...and many more
- 9. Selecting aCDN Service ● Dependson your needs, e.g. Mediaonly, web only, and thelike. ● Regionsyou need served. ● Dependson theclient'spricerangeand quality of serviceneeds. ● HTTPSsupport / costs (Note: Googleand other search enginesarestarting to givepreferenceto sitesthat areavailableviaHTTPS)
- 10. Common waysCDNs areused with Drupal ● Mediaand largefiledelivery (e.g. YouTube, Vimeo, and others) ● Static filedelivery (CSS, Images, JS, and thelike) ● Full anonymoussitecaching
- 11. MediaDelivery ● SiteDNSpointsto origin ● Content pointsto CDN DNS when needed ● Filesareadded viaCDNsadmin interface Pros ● Largefilesdelivered efficiently ● Normal Drupal behavior Cons ● CDN delivered filesmay haveto bemanually set up/managed.
- 12. Static FileDelivery ● SiteDNSpointsto origin ● CDN modulecan automatically rewritestatic URLsto CDN DNS ● Filesareautomatically cached Pros ● Server load reduced ● Set and (almost) forget Cons ● Can beadelay updating files that areREPLACED.
- 13. Full SiteDelivery ● SiteDNSpointsto CDN cluster ● No special moduleslikeCDN needed, filesareautomatically added to thecache. Pros ● Supportsmost clientswith least impact on origin Cons ● Morecomplex set up ● Need to defineprocessesto allow content managersto refresh updated content
- 14. Challengesto using CDNsand Drupal ● CDNsservecached content based on URLs ● User based Drupal sitescan havedifferent content displayed using thesameURL, e.g. /user ● Content editorswant to seechangesimmediately and not wait for cacheto refresh ● Network managerswant cacheto last along timeto lower server load
- 15. Selecting aCDN mode A quick ruleof thumb for deciding between Full site delivery and Static filedelivery is: ● Doesyour sitesupport individual users? Yes- UseStatic filedelivery No – UseFull site Note: CDNsalso havevarioussettingsthat may let you createahybrid site, e.g. deliver certain areasvia CDN but let Cart or Forum or... areasbestatic only.
- 16. SomeUseful Modules ● CDN isuseful for setting up static fileservices http://drupal.org/project/cdn ● CloudFront Refresh (my module:) ) http://drupal.org/sandbox/cgmonroe/2454357 ● AdvancedAggregation – Doesabetter job of css and javascript aggregation http://drupal.org/project/advagg
- 17. A CaseStudy ● A collegehasacoach who lovesto set sports records... likeaplayer scoring 130+ point in agame, which leadsto massiveload on their main web site. ● Thecommunicationsdepartment isvery proactivein updating thecontent and want visitorsto seethings immediately ● Themain websiteisaccessed by anonymoususers with theexception of variouscontent manager ● They want to support HTTPSto get the“Google” ranking boost.
- 18. Strategy Used ● UseCloudFront CDN serviceasafull sitedelivery service. ● UseServer NameIndication Certificatesto allow HTTPSon multipleDNSnames ● Use“origin” DNSentry to bypassCDN for content editors ● Writeacustom moduleto allow content to easily be refreshed on theCDN cluster
- 19. Set up CloudFront Distro
- 20. Set up CloudFront Distro
- 22. Set up DNS ● Thewww.college.edu siteisset up with aCNAME entry thepointsto theCloudfront.net DNSentry ● The“edit” siteusesorigin.college.edu and pointsto theserver'sIPaddress
- 23. Setup theCertificates ● Get and SNI SSL certificatewith all theDNSnames you want thesiteto beknown as. E.g. origin.college.edu and www.college.edu ● Install thecertificateon theAmazon CF Distribution (seeAmazon docs) ● Install thecertificateon theorigin server
- 24. .htaccessSetup To set aspecific expiresheader / time... look for thesection likethisand modify asneeded. NOTE: Drupal pagesexpiretimebased on Pagecachetimesetting in config->devel- >performance. # Requires mod_expires to be enabled. <IfModule mod_expires.c> # Enable expirations. ExpiresActive On # Short expires for testing. ExpiresDefault "access plus 1 minutes" <FilesMatch .php$> # Do not allow PHP scripts to be cached unless they explicitly send cache # headers themselves. Otherwise all scripts would have to overwrite the # headers setby mod_expires if they want another caching behavior. This may # fail if an error occurs early in the bootstrap process, and it may cause # problems if a nonDrupal PHP file is installed in a subdirectory. ExpiresActive Off </FilesMatch> </IfModule>
- 25. .htaccessSetup Redirect login'sto origin site: # Redirect logins to nonCDN site RewriteCond %{HTTP_HOST} !^origin.college.edu [NC] RewriteRule ^user/login$ https://origin.college.edu/user/login [R=301,L] RewriteCond %{HTTP_HOST} !^origin.college.edu [NC] RewriteRule ^user$ https://origin.college.edu/user [R=301,L]
- 26. .htaccessSetup If you usecustom fonts, you will need to prevent CORS security errors, usethefollowing. NOTE: needsto be tweaked if you want to limit to specific sites. <IfModule mod_headers.c> Header set AccessControlAllowOrigin * # SetEnvIf Origin "^(.*.college.edu)$" ORIGIN_SUB_DOMAIN=$1 # <FilesMatch ".woff$"> # Header set AccessControlAllowOrigin "% {ORIGIN_SUB_DOMAIN}e" env=ORIGIN_SUB_DOMAIN # </FilesMatch> </IfModule>
- 27. Settings.php Setup Thefollowing codeletstheCDN support HTTPS. Needsto bein thesettings.php file. if (isset($_SERVER['HTTP_CLOUDFRONT_FORWARDED_PROTO']) && $_SERVER['HTTP_CLOUDFRONT_FORWARDED_PROTO'] == 'https') { $_SERVER['HTTPS'] = 'on'; $_SERVER['HTTP_X_FORWARDED_PROTO'] = 'https'; } // The following are only needed if the 'nonCDN' site can be // accessed by more than 1 host name E.g., initially an internal // DNS entry and then moved to a client DNS entry. if ( isset($_SERVER['HTTP_HOST']) && $_SERVER['HTTP_HOST'] == 'collegeorigin.longsight.com') { $_SERVER['HTTP_HOST'] = 'origin.college.edu'; }
- 28. Setup CloudFront Refresh Module ● Get thenew CloudFront Refresh modulefrom itssandbox: http://drupal.org/sandbox/cgmonroe/2454357 ● Get dependancies: http://drupal.org/project/libraries(if needed) http://drupal.org/project/awssdk ● Follow theCloudFront Refresh install instructions
- 29. CloudFront Refresh ● Tracksupdated nodesand sendsinvalidaterequest when sitecacheiscleared ● Allowsmanually entering URL to refresh non-html files ● Statuspageto track refresh requests ● Someother codeto improve CDN hit rates
- 30. Results ● Entiresiteisserviced viaCDN with low hit rateon main server ● Fast responseeven under load ● Content editor can instantly seethechangesthey are editing becauseloginsget redirected to theorigin site. ● CloudFront Refresh modulemakeiseasy for updatesto be“pushed” out to CDN.
- 31. SomeTroubleshooting/Testing Tips ● curl -I -L http://www.college.edu/<path> Thisgetstheheadersfor thepath with expiretimeand other information. For example, you can check theexpiretimeon pagescoming from theorigin server. ● Chrome/ Firebug network load tab Thiscan beused to determinewhat isbeing loaded from which server (or not being loaded). ● Think ahead. CDNsaresimilar to DNSserverswith propagation delays. If a siteisgoing to havemajor changes, set theorigin expiretime to alow valueaday or so before.
- 32. Questions?