Varnish settings to run with magento

Question

I am creating an ecommerce site using magento.

I am using nginx, php5-fpm.

I have 512mb RAM and 4CPU cores.

I want to use varnish with these specifications. I want to know what values should i set in the varnish configuration so that my server can handle maximum requests with minimum delay? I have tried some varnish configuration but response time i am getting is greater than i was getting without varnish.

Answer 1

This is the setup I always use. Comes from the PageCache powered by Varnish module for magento. I've actually written about setting up this

# This is a basic VCL configuration file for PageCache powered by Varnish for Magento module.

# default backend definition.  Set this to point to your content server.
backend default {
  .host = "127.0.0.1";
  .port = "8080";
}

# admin backend with longer timeout values. Set this to the same IP & port as your default server.
backend admin {
  .host = "127.0.0.1";
  .port = "8080";
  .first_byte_timeout = 18000s;
  .between_bytes_timeout = 18000s;
}


# add your Magento server IP to allow purges from the backend
acl purge {
  "localhost";
  "127.0.0.1";
}


sub vcl_recv {
    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" &&
      req.request != "PURGE") {
        /* Non-RFC2616 or CONNECT which is weird. */
        return (pipe);
    }

    # purge request
    if (req.request == "PURGE") {
        if (!client.ip ~ purge) {
            error 405 "Not allowed.";
        }
        purge("obj.http.X-Purge-Host ~ " req.http.X-Purge-Host " && obj.http.X-Purge-URL ~ " req.http.X-Purge-Regex " && obj.http.Content-Type ~ " req.http.X-Purge-Content-Type);
        error 200 "Purged.";
    }

    # switch to admin backend configuration
    if (req.http.cookie ~ "adminhtml=") {
        set req.backend = admin;
    }

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

    # normalize url in case of leading HTTP scheme and domain
    set req.url = regsub(req.url, "^http[s]?://[^/]+", "");

    # static files are always cacheable. remove SSL flag and cookie
    if (req.url ~ "^/(media|js|skin)/.*\.(png|jpg|jpeg|gif|css|js|swf|ico)$") {
        unset req.http.Https;
        unset req.http.Cookie;
    }

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

    # do not cache any page from
    # - index files
    # - ...
    if (req.url ~ "^/(index)") {
        return (pass);
    }

    # as soon as we have a NO_CACHE cookie pass request
    if (req.http.cookie ~ "NO_CACHE=") {
        return (pass);
    }

    # normalize Aceept-Encoding header
    # http://varnish.projects.linpro.no/wiki/FAQ/Compression
    if (req.http.Accept-Encoding) {
        if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf|flv)$") {
            # No point in compressing these
            remove req.http.Accept-Encoding;
        } elsif (req.http.Accept-Encoding ~ "gzip") {
            set req.http.Accept-Encoding = "gzip";
        } elsif (req.http.Accept-Encoding ~ "deflate" && req.http.user-agent !~ "MSIE") {
            set req.http.Accept-Encoding = "deflate";
        } else {
            # unkown algorithm
            remove req.http.Accept-Encoding;
        }
    }

    # remove Google gclid parameters
    set req.url = regsuball(req.url,"\?gclid=[^&]+$",""); # strips when QS = "?gclid=AAA"
    set req.url = regsuball(req.url,"\?gclid=[^&]+&","?"); # strips when QS = "?gclid=AAA&foo=bar"
    set req.url = regsuball(req.url,"&gclid=[^&]+",""); # strips when QS = "?foo=bar&gclid=AAA" or QS = "?foo=bar&gclid=AAA&bar=baz"

    return (lookup);
}

sub vcl_hash {
    set req.hash += req.url;
    if (req.http.host) {
         set req.hash += req.http.host;
    } else {
        set req.hash += server.ip;
    }
    if (!(req.url ~ "^/(media|js|skin)/.*\.(png|jpg|jpeg|gif|css|js|swf|ico)$")) {
        call design_exception;
    }
    return (hash);
}

sub vcl_fetch {
    if (beresp.status == 500) {
       set beresp.saintmode = 10s;
       restart;
    }
    set beresp.grace = 5m;

    # add ban-lurker tags to object
    set beresp.http.X-Purge-URL = req.url;
    set beresp.http.X-Purge-Host = req.http.host;

    if (beresp.status == 200 || beresp.status == 301 || beresp.status == 404) {
        if (beresp.http.Content-Type ~ "text/html" || beresp.http.Content-Type ~ "text/xml") {
            if ((beresp.http.Set-Cookie ~ "NO_CACHE=") || (beresp.ttl < 1s)) {
                set beresp.ttl = 0s;
                return (pass);
            }

            # marker for vcl_deliver to reset Age:
            set beresp.http.magicmarker = "1";

            # Don't cache cookies
            unset beresp.http.set-cookie;
        } else {
            # set default TTL value for static content
            set beresp.ttl = 4h;
        }
        return (deliver);
    }

    return (pass);
}

sub vcl_deliver {
    # debug info
    if (resp.http.X-Cache-Debug) {
        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";
        }
        set resp.http.X-Cache-Expires = resp.http.Expires;
    } else {
        # remove Varnish/proxy header
        remove resp.http.X-Varnish;
        remove resp.http.Via;
        remove resp.http.Age;
        remove resp.http.X-Purge-URL;
        remove resp.http.X-Purge-Host;
    }

    if (resp.http.magicmarker) {
        # Remove the magic marker
        unset resp.http.magicmarker;

        set resp.http.Cache-Control = "no-store, no-cache, must-revalidate, post-check=0, pre-check=0";
        set resp.http.Pragma = "no-cache";
        set resp.http.Expires = "Mon, 31 Mar 2008 10:00:00 GMT";
        set resp.http.Age = "0";
    }
}

sub design_exception {
}