• Concept / configuration

• Tuto 1
• Tuto 2
• Varnish et les vhosts
• Purger le cache
• Forcer le cache sur Varnish plutôt que sur les clients

• Benchmark

Il est possible de changer des valeurs à chaud avec l'interface d'administration en ligne de commande :

varnishadm -T localhost:6082 -S /etc/varnish/secret

• Surveiller varnish

Par exemple, pour savoir quelles URLs sont demandées par les clients au serveur Varnish:

varnishtop -i rxurl

Pour savoir quelles requêtes sont transmises par Varnish au serveur web (Apache):

varnishtop -i txurl

Voir ce qui est demandé au serveur Apache pour /membres/chat :

varnishlog -b -i TxURL -I '^/membres/chat/'

#http://blog.jeremm.fr/?tag=vcl
sub vcl_recv {
    # Serve objects up to 2 minutes past their expiry if the backend is slow to respond
    set req.grace = 120s;

    # Normalize encoding/compression
    if (req.http.Accept-Encoding) {
        if (req.http.Accept-Encoding ~ "gzip") { set req.http.Accept-Encoding = "gzip"; }
        elsif (req.http.Accept-Encoding ~ "deflate") { set req.http.Accept-Encoding = "deflate"; }
        else { remove req.http.Accept-Encoding; }
    }

    if (req.restarts == 0) {
      if (req.http.x-forwarded-for) {
          set req.http.X-Forwarded-For =
              req.http.X-Forwarded-For + ", " + client.ip;
      } else {
          set req.http.X-Forwarded-For = client.ip;
      }
    }

    if (req.request != "GET" &&
      req.request != "HEAD" &&
      req.request != "PUT" &&
      req.request != "POST" &&
      req.request != "TRACE" &&
      req.request != "OPTIONS" &&
      req.request != "DELETE") {
          # Non-RFC2616 or CONNECT which is weird.
          return (pipe);
    }

    if (req.request != "GET" && req.request != "HEAD") {
        # We only deal with GET and HEAD by default
        return (pass);
    }

    # If the request is static
    if (req.url ~ "\.(jpeg|jpg|png|gif|bmp|ico|js|css|txt|gz|zip|lzma|bz2|tgz|tbz|html|htm)$") {
        # Make the request static by removing any cookies set by those static files
        unset req.http.cookie;
        return (lookup);
    }

    if (req.http.Authorization || req.http.Cookie) {
        # Not cacheable by default
        return (pass);
    }

    return (lookup);
}

sub vcl_pass {
        set req.http.X-marker = "pass" ;
}

sub vcl_fetch {
    set beresp.grace = 120s;
    unset beresp.http.Server;

    # Maximum 24h de cache
    set beresp.ttl = 86400s;
    set beresp.http.cache-control = "max-age=0";
    remove beresp.http.Pragma;
    remove beresp.http.Expires;

    if (req.http.X-marker == "pass") {
            unset req.http.X-marker;
            set beresp.http.X-marker = "pass";
            #set beresp.ttl = 0s ;
    }

    # If the request is static
    if (req.url ~ "\.(jpeg|jpg|png|gif|bmp|ico|js|css|txt|gz|zip|lzma|bz2|tgz|tbz|html|htm)$") {
        # Cache it, and make it last 24 hours
        set beresp.ttl = 86400s;
        # Make the request static by removing any cookies set by those static files
        unset beresp.http.set-cookie;
        # Deliver the cached object
        #return (deliver);
    }

    return (deliver);
}

sub vcl_deliver {
        if (obj.hits > 0){
                set resp.http.X-Gigix-Cache = "HIT";
        }else{
                set resp.http.X-Gigix-Cache = "MISS";
        }
        if (resp.http.X-marker == "pass" ) {
                remove resp.http.X-marker;
                set resp.http.X-Gigix-Cache = "PASS";
        }

        remove resp.http.Via;
        remove resp.http.X-Varnish;
        remove resp.http.Server;
        remove resp.http.X-Powered-By;
 }

Changer le LogFormat par :

LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" varnishcombined

Puis changer dans les vhosts :

CustomLog /var/log/apache2/domain.com-access.log varnishcombined