# # Customized VCL file for serving up a Drupal site with multiple back-ends. # # For more information on this VCL, visit the Lullabot article: # http://www.lullabot.com/articles/varnish-multiple-web-servers-drupal # # Define the internal network subnet. # These are used below to allow internal access to certain files while not # allowing access from the public internet. acl internal { "192.10.0.0"/24; } # Define the list of backends (web servers). # Port 80 Backend Servers backend web1 { .host = "192.10.0.1"; .probe = { .url = "/status.php"; .interval = 5s; .timeout = 1s; .window = 5;.threshold = 3; }} backend web2 { .host = "192.10.0.2"; .probe = { .url = "/status.php"; .interval = 5s; .timeout = 1s; .window = 5;.threshold = 3; }} # Port 443 Backend Servers for SSL backend web1_ssl { .host = "192.10.0.1"; .port = "443"; .probe = { .url = "/status.php"; .interval = 5s; .timeout = 1 s; .window = 5;.threshold = 3; }} backend web2_ssl { .host = "192.10.0.2"; .port = "443"; .probe = { .url = "/status.php"; .interval = 5s; .timeout = 1 s; .window = 5;.threshold = 3; }} # Define the director that determines how to distribute incoming requests. director default_director round-robin { { .backend = web1; } { .backend = web2; } } director ssl_director round-robin { { .backend = web1_ssl; } { .backend = web2_ssl; } } # Respond to incoming requests. sub vcl_recv { # Set the director to cycle between web servers. if (server.port == 443) { set req.backend = ssl_director; } else { set req.backend = default_director; } # Use anonymous, cached pages if all backends are down. if (!req.backend.healthy) { unset req.http.Cookie; } # Allow the backend to serve up stale content if it is responding slowly. set req.grace = 6h; # Do not cache these paths. if (req.url ~ "^/status\.php$" || req.url ~ "^/update\.php$" || req.url ~ "^/ooyala/ping$" || req.url ~ "^/admin/build/features" || req.url ~ "^/info/.*$" || req.url ~ "^/flag/.*$" || req.url ~ "^.*/ajax/.*$" || req.url ~ "^.*/ahah/.*$") { return (pass); } # Pipe these paths directly to Apache for streaming. if (req.url ~ "^/admin/content/backup_migrate/export") { return (pipe); } # Do not allow outside access to cron.php or install.php. if (req.url ~ "^/(cron|install)\.php$" && !client.ip ~ internal) { # Have Varnish throw the error directly. error 404 "Page not found."; # Use a custom error page that you've defined in Drupal at the path "404". # set req.url = "/404"; } # Handle compression correctly. Different browsers send different # "Accept-Encoding" headers, even though they mostly all support the same # compression mechanisms. By consolidating these compression headers into # a consistent format, we can reduce the size of the cache and get more hits.= # @see: http:// varnish.projects.linpro.no/wiki/FAQ/Compression if (req.http.Accept-Encoding) { if (req.http.Accept-Encoding ~ "gzip") { # If the browser supports it, we'll use gzip. set req.http.Accept-Encoding = "gzip"; } else if (req.http.Accept-Encoding ~ "deflate") { # Next, try deflate if it is supported. set req.http.Accept-Encoding = "deflate"; } else { # Unknown algorithm. Remove it and send unencoded. unset req.http.Accept-Encoding; } } # Always cache the following file types for all users. if (req.url ~ "(?i)\.(png|gif|jpeg|jpg|ico|swf|css|js|html|htm)(\?[a-z0-9]+)?$") { unset req.http.Cookie; } # Remove all cookies that Drupal doesn't need to know about. ANY remaining # cookie will cause the request to pass-through to Apache. For the most part # we always set the NO_CACHE cookie after any POST request, disabling the # Varnish cache temporarily. The session cookie allows all authenticated users # to pass through as long as they're logged in. if (req.http.Cookie) { set req.http.Cookie = ";" + req.http.Cookie; set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";"); set req.http.Cookie = regsuball(req.http.Cookie, ";(SESS[a-z0-9]+|NO_CACHE)=", "; \1="); set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", ""); set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", ""); if (req.http.Cookie == "") { # If there are no remaining cookies, remove the cookie header. If there # aren't any cookie headers, Varnish's default behavior will be to cache # the page. unset req.http.Cookie; } else { # If there is any cookies left (a session or NO_CACHE cookie), do not # cache the page. Pass it on to Apache directly. return (pass); } } } # Routine used to determine the cache key if storing/retrieving a cached page. sub vcl_hash { # Include cookie in cache hash. # This check is unnecessary because we already pass on all cookies. # if (req.http.Cookie) { # set req.hash += req.http.Cookie; # } } # Code determining what to do when serving items from the Apache servers. sub vcl_fetch { # Don't allow static files to set cookies. if (req.url ~ "(?i)\.(png|gif|jpeg|jpg|ico|swf|css|js|html|htm)(\?[a-z0-9]+)?$") { # beresp == Back-end response from the web server. unset beresp.http.set-cookie; } # Allow items to be stale if needed. set beresp.grace = 6h; } # In the event of an error, show friendlier messages. sub vcl_error { # Redirect to some other URL in the case of a homepage failure. #if (req.url ~ "^/?$") { # set obj.status = 302; # set obj.http.Location = "http://backup.example.com/"; #} # Otherwise redirect to the homepage, which will likely be in the cache. set obj.http.Content-Type = "text/html; charset=utf-8"; synthetic {" Page Unavailable

Page Unavailable

The page you requested is temporarily unavailable.

We're redirecting you to the homepage in 5 seconds.

(Error "} + obj.status + " " + obj.response + {")
"}; return (deliver); }