Varnish Magento

Use varnish reverse proxy cache to increase performance and scalability of Magento. Delivered at Magento Developer Paradise #mdp2011

Transcript

1. Ibiza, June 4th – 7th 2011
   Monday, 6 June 2011
   

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2. VARNISH
   YOUR
   MAGENTO STORE
   Make it fly!
   Monday, 6 June 2011
   

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3. WHO AM I
   • Alistair Stead - @alistairstead
   • Technical Team Lead @ Ibuildings UK / Session Digital
   • Lead Magento projects for Dreams, 3663, Kookai and others
   • Author of MageTool and MageTest
   • Zend Certified Engineer
   • Over 11 years commercial experience developing in PHP
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4. PERFORMANCE AND SCALABILITY
   Is a hot topic for clients and developers alike.
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5. PERFORMANCE
   Vs
   CONVERSION RATE
   These are directly linked!
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6. PERCEIVED PERFORMANCE
   Vs
   PHYSICAL PERFORMANCE
   Is there an easy route to performance?
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7. VARNISH
   http://www.varnish-cache.org/
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8. PRELIMINARY LOAD TESTS
   What can Varnish do for us?
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9. +4,000,000
   Requests per hour
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10. REVERSE PROXY?
    Yeah okay... tell me more!
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11. CACHING PROXY?
    It is...
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12. LOAD BALANCER?
    It can do that too!
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13. HTTP ACCELERATOR
    It may just be magic!
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14. HOW TO CONTROL CACHING
    Additional caching layers need to be coordinated
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15. RFC 2616 HTTP 1.1
    http://www.w3.org/Protocols/rfc2616/rfc2616.html
    http://tools.ietf.org/wg/httpbis/
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16. HTTP 1.1
    $ curl -I magentocommerce.com
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17. HTTP/1.1 200 OK
    Server: nginx
    Date: Sun, 05 Jun 2011 17:40:56 GMT
    Content-Type: text/html; charset=UTF-8
    Connection: keep-alive
    X-Powered-By: PHP/5.2.17
    Set-Cookie: PHPSESSID=j1cdbj2617abbl8ccsbkd2mt44; path=/
    Expires: Mon, 26 Jul 1997 05:00:00 GMT
    Cache-Control: no-store, no-cache, must-revalidate, post-
    check=0, pre-check=0
    Pragma: no-cache
    Last-Modified: Sun, 05 Jun 2011 17:40:56 GMT
    $ curl -I magentocommerce.com
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18. HTTP 1.1 HEADERS
    Request modifiers / Response parameters
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19. CACHEING WITH HTTP 1.1
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20. EXPIRATION MODEL
    How long may I use this resource for?
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21. EXPIRATION HEADERS
    • Cache-Control
    • Expires
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22. VALIDATION MODEL
    Is this resource still okay to use?
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23. VALIDATION HEADERS
    • Last-Modified
    • If-Modified-Since
    • ETag
    • If-None-Match
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24. HTTP CACHE HEADERS
    Only work with safe HTTP verbs GET & HEAD
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25. HTTP 1.1 REQUEST FLOW
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26. Client
    Application
    Client Cache
    GET / HTTP1.1
    Host: mystore.com
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    HTTP1.1 200 OK
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27. Client
    Application
    Client Cache
    GET / HTTP1.1
    Host: mystore.com
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
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28. Client
    Application
    Client Cache
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
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29. Client
    Application
    Client Cache
    GET / HTTP1.1
    Host: mystore.com
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Etag: abcde
    HTTP1.1 200 OK
    Etag: abcde
    HTTP1.1 200 OK
    Etag: abcde
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30. Client
    Application
    Client Cache
    GET / HTTP1.1
    Host: mystore.com GET / HTTP1.1
    Host: mystore.com
    If-None-Match: abcde
    HTTP1.1 304 Not
    Modified
    HTTP1.1 304 Not
    Modified
    HTTP1.1 200 OK
    Etag: abcde
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31. EXPIRATION ALLOWS YOU TO SCALE
    VALIDATION SAVES BANDWIDTH
    Fewer requests hitting your server and client speed is better too!
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32. OUR GOAL IS TO NEVER GENERATE THE
    SAME RESPONSE TWICE
    HTTP caching can help
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33. LEVERAGE HTTP CACHE IN MAGENTO
    With an event observer this is simple.
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34. class Disclosure_Varnish_Model_Observer extends Disclosure_Varnish_Model_Observer_Abstract
    {
    /**
    * Update the headers transmitted to allow greater varnish cache hits
    *
    * @param $observer
    */
    public function processPreDispatch(Varien_Event_Observer $observer)
    {
    if (!$this->isVarnishEnabled()) {
    return $this;
    }
    $routeTtls = $this->_config->getRouteTtls();
    $routeName = Mage::app()->getRequest()->getRequestedRouteName();
    if (isset($routeTtls[$routeName])) {
    $observer->getResponse()->setHeader('Cache-Control', $routeTtls[$routeName]['cache_control'], false);
    }
    return $this;
    }
    }
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35. 
    
    
    
    
    cms
    public, max-age=3600
    
    
    catalog
    public, must-revalidate, max-age=0
    
    
    private, max-age=0
    
    
    
    
    
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36. USE VARNISH WITH MAGENTO
    Add shared cache to reduce the load on the application
    Client
    Browser
    Varnish
    Port 80
    Backend
    Apache
    Port 8080
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37. VARNISH RESPECTS CACHE CONTROL
    Dispatch the headers that fit your application
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38. Client
    Application
    Client Cache
    Reverse Proxy Cache
    GET / HTTP1.1
    Host: mystore.com
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
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39. Client
    Application
    Client Cache
    Reverse Proxy Cache
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
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40. Client
    Application
    Client Cache
    Reverse Proxy Cache
    GET / HTTP1.1
    Host: mystore.com
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
    Client
    Client Cache
    GET / HTTP1.1
    Host: mystore.com
    HTTP1.1 200 OK
    Cache-Control: max-
    age=20
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41. Client
    Application
    Client Cache
    Reverse Proxy Cache
    Client
    Client Cache
    Gateway Cache
    Network Proxy Cache
    max-age
    s-maxage
    max-age
    s-maxage
    max-age
    s-maxage
    max-age
    max-age
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42. VARNISH IS CONFIGURED USING VCL
    Send the correct headers you should not need to do much.
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43. sub vcl_recv {
    set req.http.Surrogate-Capability = "magento=ESI/1.0";
    return (lookup);
    }
    sub vcl_fetch {
    if (beresp.http.Surrogate-Control ~ "ESI/1.0") {
    # unset beresp.http.Surrogate-Control;
    esi;
    }
    return (deliver);
    }
    sub vcl_deliver {
    # Set a cache header to allow us to inspect the response
    # headers during testing
    if (obj.hits > 0) {
    set resp.http.X-Cache = "HIT";
    set resp.http.X-Cache-Hits = obj.hits;
    } else {
    set resp.http.X-Cache = "MISS";
    }
    }
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44. EDGE SIDE INCLUDES
    http://www.w3.org/TR/esi-lang
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45. max-age=3600
    max-age=86400
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46. max-age=3600
    max-age=86400
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47. ESI TAGS
    
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48. /**
    * Render ESI tags for the block if needed
    *
    * @param Varien_Event_Observer $observer
    */
    public function renderBlockEsiTag(Varien_Event_Observer $observer)
    {
    if (!$this->isEsiEnabled() || !$this->isVarnishEnabled()) {
    return $this;
    }
    $block = $observer->getEvent()->getBlock();
    $transport = $observer->getEvent()->getTransport();
    $tag = Mage::getModel('varnish/esi_tag_factory')->create($block);
    if ($transport && $tag) {
    $transport->setHtml($tag->getHtml());
    }
    return $this;
    }
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49. /**
    * Render the html for the ESI tag
    *
    * @return string
    * @author Alistair Stead
    **/
    public function getHtml()
    {
    return sprintf(
    '',
    $this->getAttributeHash()
    );
    }
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50. class Disclosure_Varnish_EsiController extends Mage_Core_Controller_Front_Action
    {
    public function indexAction()
    {
    $attributes = unserialize(base64_decode($this->getRequest()->getParam('attributes')));
    $context = Mage::getModel('varnish/esi_context');
    $context->setData($attributes);
    $processor = Mage::getModel('varnish/esi_processor', $context);
    // Initialize the layout
    $this->loadLayout();
    Mage::dispatchEvent('varnish_controller_esi_appendbody_before', array("response" => $this->getResponse()));
    $this->getResponse()->appendBody($processor->render());
    Mage::dispatchEvent('varnish_controller_esi_appendbody_after', array("response" => $this->getResponse()));
    }
    }
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51. FINAL PERFORMANCE RESULTS
    How much traffic did these modifications let us serve
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52. TRAFFIC SAMPLE
    • Product Details page: 58k views per hour
    • Homepage: 50k requests per hour
    • Main Search : 70k requests per hour
    • Refined Search (via facets): 20k requests per
    hour
    • Add to Basket: 11k requests per hour
    • Login: 11k requests per hour
    • Category Pages: 46k requests per hour
    • Checkout: 6k requests per hour
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53. Homepage
    Category Listings
    Product Detail
    Add to cart
    Login
    Search
    Purchase
    0 375000 750000 1125000 1500000
    Client Baseline Magento Baseline Magento Compiler Magento + Varnish
    FINAL PERFORMANCE RESULTS
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54. NON CACHEABLE TRANSACTIONS
    Add to cart
    Purchase
    0 7500 15000 22500 30000
    Client Baseline Magento Baseline Magento Compiler Magento + Varnish
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55. Monday, 6 June 2011
    

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56. THE TARGET ~ 300K REQUEST
    We achieved almost 14 x that with little effort.
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57. IS VARNISH THE BEST SOLUTION?
    What do we need to consider?
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58. VARNISH LIMITATIONS
    • Does not currently support GZIP
    • Cookies need to be managed carefully
    • Still need SSL endpoint
    • Routing and URL generation can be tricky
    • Beware cache stampede
    • ESI must have a TTL greater than the parent page
    • Shared cache consider using s-maxage with max-age
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59. ADDITIONAL OPTIONS
    Other HTTP caching options and solutions
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60. CLIENT SIDE INCLUDES
    A common pattern using Ajax
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61. STALE WHILE
    Maintain a compromised UI while resolving content
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62. ALTERNATE WHILE
    Provide alternate content will content is being resolved
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63. REFERENCES
    • http://blog.sessiondigital.com/post/5764403845/high-performance-magento
    • http://www.varnish-cache.org/
    • http://www.w3.org/Protocols/rfc2616/rfc2616.html
    • http://tools.ietf.org/wg/httpbis/
    • http://www.w3.org/TR/esi-lang
    • http://www.fabrizio-branca.de/make-your-magento-store-fly-using-varnish.html
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64. IMAGE CREDITS
    http://www.flickr.com/photos/bondgirly/4520060395/sizes/o/in/photostream/
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65. THANK YOU!
    • Email: astead@ibuildings.com
    • Skype: astead-ibuildings
    • Twitter: @alistairstead
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66. QUESTIONS?
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67. WE ARE HIRING!
    http://www.ibuildings.co.uk/about/careers/
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68. Monday, 6 June 2011
    

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