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I'm trying to install varnish and I'm baffled about which configurations default.vcl file to use.

The scenario: 1- I exported the magento varnish configuration file using the command bin/magento varnish:vcl:generate --export-version=6 | tee ./default.vcl > /dev/null

And this is the output file:

# VCL version 5.0 is not supported so it should be 4.0 even though actually used Varnish version is 6
vcl 4.0;

import std;
# The minimal Varnish version is 6.0
# For SSL offloading, pass the following header in your proxy server or load balancer: 'X-Forwarded-Proto: https'

backend default {
    .host = "localhost";
    .port = "8080";
    .first_byte_timeout = 600s;
    .probe = {
        .url = "/pub/health_check.php";
        .timeout = 2s;
        .interval = 5s;
        .window = 10;
        .threshold = 5;
   }
}

acl purge {
    "localhost";
}

sub vcl_recv {
    if (req.restarts > 0) {
        set req.hash_always_miss = true;
    }

    if (req.method == "PURGE") {
        if (client.ip !~ purge) {
            return (synth(405, "Method not allowed"));
        }
        # To use the X-Pool header for purging varnish during automated deployments, make sure the X-Pool header
        # has been added to the response in your backend server config. This is used, for example, by the
        # capistrano-magento2 gem for purging old content from varnish during it's deploy routine.
        if (!req.http.X-Magento-Tags-Pattern && !req.http.X-Pool) {
            return (synth(400, "X-Magento-Tags-Pattern or X-Pool header required"));
        }
        if (req.http.X-Magento-Tags-Pattern) {
          ban("obj.http.X-Magento-Tags ~ " + req.http.X-Magento-Tags-Pattern);
        }
        if (req.http.X-Pool) {
          ban("obj.http.X-Pool ~ " + req.http.X-Pool);
        }
        return (synth(200, "Purged"));
    }

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

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

    # Bypass customer, shopping cart, checkout
    if (req.url ~ "/customer" || req.url ~ "/checkout") {
        return (pass);
    }

    # Bypass health check requests
    if (req.url ~ "^/(pub/)?(health_check.php)$") {
        return (pass);
    }

    # Set initial grace period usage status
    set req.http.grace = "none";

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

    # collect all cookies
    std.collect(req.http.Cookie);

    # Compression filter. See https://www.varnish-cache.org/trac/wiki/FAQ/Compression
    if (req.http.Accept-Encoding) {
        if (req.url ~ "\.(jpg|jpeg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf|flv)$") {
            # No point in compressing these
            unset 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 {
            # unknown algorithm
            unset req.http.Accept-Encoding;
        }
    }

    # Remove all marketing get parameters to minimize the cache objects
    if (req.url ~ "(\?|&)(gclid|cx|ie|cof|siteurl|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=") {
        set req.url = regsuball(req.url, "(gclid|cx|ie|cof|siteurl|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=[-_A-z0-9+()%.]+&?", "");
        set req.url = regsub(req.url, "[?|&]+$", "");
    }

    # Static files caching
    if (req.url ~ "^/(pub/)?(media|static)/") {
        # Static files should not be cached by default
        return (pass);

        # But if you use a few locales and don't use CDN you can enable caching static files by commenting previous line (#return (pass);) and uncommenting next 3 lines
        #unset req.http.Https;
        #unset req.http.X-Forwarded-Proto;
        #unset req.http.Cookie;
    }

    # Bypass authenticated GraphQL requests without a X-Magento-Cache-Id
    if (req.url ~ "/graphql" && !req.http.X-Magento-Cache-Id && req.http.Authorization ~ "^Bearer") {
        return (pass);
    }

    return (hash);
}

sub vcl_hash {
    if ((req.url !~ "/graphql" || !req.http.X-Magento-Cache-Id) && req.http.cookie ~ "X-Magento-Vary=") {
        hash_data(regsub(req.http.cookie, "^.*?X-Magento-Vary=([^;]+);*.*$", "\1"));
    }

    # To make sure http users don't see ssl warning
    if (req.http.X-Forwarded-Proto) {
        hash_data(req.http.X-Forwarded-Proto);
    }
    

    if (req.url ~ "/graphql") {
        call process_graphql_headers;
    }
}

sub process_graphql_headers {
    if (req.http.X-Magento-Cache-Id) {
        hash_data(req.http.X-Magento-Cache-Id);

        # When the frontend stops sending the auth token, make sure users stop getting results cached for logged-in users
        if (req.http.Authorization ~ "^Bearer") {
            hash_data("Authorized");
        }
    }

    if (req.http.Store) {
        hash_data(req.http.Store);
    }

    if (req.http.Content-Currency) {
        hash_data(req.http.Content-Currency);
    }
}

sub vcl_backend_response {

    set beresp.grace = 3d;

    if (beresp.http.content-type ~ "text") {
        set beresp.do_esi = true;
    }

    if (bereq.url ~ "\.js$" || beresp.http.content-type ~ "text") {
        set beresp.do_gzip = true;
    }

    if (beresp.http.X-Magento-Debug) {
        set beresp.http.X-Magento-Cache-Control = beresp.http.Cache-Control;
    }

    # cache only successfully responses and 404s that are not marked as private
    if (beresp.status != 200 &&
            beresp.status != 404 &&
            beresp.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        set beresp.ttl = 86400s;
        return (deliver);
    }

    # validate if we need to cache it and prevent from setting cookie
    if (beresp.ttl > 0s && (bereq.method == "GET" || bereq.method == "HEAD")) {
        unset beresp.http.set-cookie;
    }

   # If page is not cacheable then bypass varnish for 2 minutes as Hit-For-Pass
   if (beresp.ttl <= 0s ||
       beresp.http.Surrogate-control ~ "no-store" ||
       (!beresp.http.Surrogate-Control &&
       beresp.http.Cache-Control ~ "no-cache|no-store") ||
       beresp.http.Vary == "*") {
        # Mark as Hit-For-Pass for the next 2 minutes
        set beresp.ttl = 120s;
        set beresp.uncacheable = true;
   }

   # If the cache key in the Magento response doesn't match the one that was sent in the request, don't cache under the request's key
   if (bereq.url ~ "/graphql" && bereq.http.X-Magento-Cache-Id && bereq.http.X-Magento-Cache-Id != beresp.http.X-Magento-Cache-Id) {
      set beresp.ttl = 0s;
      set beresp.uncacheable = true;
   }

    return (deliver);
}

sub vcl_deliver {
    if (resp.http.x-varnish ~ " ") {
        set resp.http.X-Magento-Cache-Debug = "HIT";
        set resp.http.Grace = req.http.grace;
    } else {
        set resp.http.X-Magento-Cache-Debug = "MISS";
    }

    # Not letting browser to cache non-static files.
    if (resp.http.Cache-Control !~ "private" && req.url !~ "^/(pub/)?(media|static)/") {
        set resp.http.Pragma = "no-cache";
        set resp.http.Expires = "-1";
        set resp.http.Cache-Control = "no-store, no-cache, must-revalidate, max-age=0";
    }

    if (!resp.http.X-Magento-Debug) {
        unset resp.http.Age;
    }
    unset resp.http.X-Magento-Debug;
    unset resp.http.X-Magento-Tags;
    unset resp.http.X-Powered-By;
    unset resp.http.Server;
    unset resp.http.X-Varnish;
    unset resp.http.Via;
    unset resp.http.Link;
}

sub vcl_hit {
    if (obj.ttl >= 0s) {
        # Hit within TTL period
        return (deliver);
    }
    if (std.healthy(req.backend_hint)) {
        if (obj.ttl + 300s > 0s) {
            # Hit after TTL expiration, but within grace period
            set req.http.grace = "normal (healthy server)";
            return (deliver);
        } else {
            # Hit after TTL and grace expiration
            return (restart);
        }
    } else {
        # server is not healthy, retrieve from cache
        set req.http.grace = "unlimited (unhealthy server)";
        return (deliver);
    }
}

2-I went to the varnish official documentation for Magento and strictly at section Optimized Magento VCL file, I found another different file

And this is the output file:

vcl 4.1;

import std;

backend default {
    .host = "localhost";
    .port = "8080";
    .first_byte_timeout = 600s;
    .probe = {
        .url = "/health_check.php";
        .timeout = 2s;
        .interval = 5s;
        .window = 10;
        .threshold = 5;
   }
}

# Add hostnames, IP addresses and subnets that are allowed to purge content
acl purge {
    "localhost";
    "127.0.0.1";
    "::1";
}

sub vcl_recv {
    # Remove empty query string parameters
    # e.g.: www.example.com/index.html?    
    if (req.url ~ "\?$") {
        set req.url = regsub(req.url, "\?$", "");
    }

    # Remove port number from host header
    set req.http.Host = regsub(req.http.Host, ":[0-9]+", "");
    
    # Sorts query string parameters alphabetically for cache normalization purposes    
    set req.url = std.querysort(req.url);
    
    # Remove the proxy header to mitigate the httpoxy vulnerability
    # See https://httpoxy.org/    
    unset req.http.proxy;

    # Add X-Forwarded-Proto header when using https
    if (!req.http.X-Forwarded-Proto && (std.port(server.ip) == 443)) {
        set req.http.X-Forwarded-Proto = "https";
    }
    
    # Reduce grace to 300s if the backend is healthy
    # In case of an unhealthy backend, the original grace is used
    if (std.healthy(req.backend_hint)) {
        set req.grace = 300s;
    }
    
    # Purge logic to remove objects from the cache
    # Tailored to Magento's cache invalidation mechanism
    if (req.method == "PURGE") {
        if (client.ip !~ purge) {
            return (synth(405, "Method not allowed"));
        }
        if (!req.http.X-Magento-Tags-Pattern && !req.http.X-Pool) {
            return (synth(400, "X-Magento-Tags-Pattern or X-Pool header required"));
        }
        if (req.http.X-Magento-Tags-Pattern) {
          ban("obj.http.X-Magento-Tags ~ " + req.http.X-Magento-Tags-Pattern);
        }
        if (req.http.X-Pool) {
          ban("obj.http.X-Pool ~ " + req.http.X-Pool);
        }
        return (synth(200, "Purged"));
    }
    
    # Only handle relevant HTTP request methods
    if (req.method != "GET" &&
        req.method != "HEAD" &&
        req.method != "PUT" &&
        req.method != "POST" &&
        req.method != "PATCH" &&
        req.method != "TRACE" &&
        req.method != "OPTIONS" &&
        req.method != "DELETE") {
          return (pipe);
    }
    
    # Only cache GET and HEAD requests
    if (req.method != "GET" && req.method != "HEAD") {
        return (pass);
    }

    # Don't cache the checkout page
    if (req.url ~ "/checkout") {
        return (pass);
    }

    # Don't cache the health check page
    if (req.url ~ "^/(pub/)?(health_check.php)$") {
        return (pass);
    }

    # Collapse multiple cookie headers into one
    std.collect(req.http.Cookie);

    # Remove tracking query string parameters used by analytics tools
    if (req.url ~ "(\?|&)(gclid|cx|ie|cof|siteurl|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=") {
        set req.url = regsuball(req.url, "(gclid|cx|ie|cof|siteurl|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=[-_A-z0-9+()%.]+&?", "");
        set req.url = regsub(req.url, "[?|&]+$", "");
    }

    # Don't cache the authenticated GraphQL requests
    if (req.url ~ "/graphql" && req.http.Authorization ~ "^Bearer") {
        return (pass);
    }

    return (hash);
}

sub vcl_hash {
    # Add a cache variation based on the X-Magento-Vary cookie
    if (req.http.cookie ~ "X-Magento-Vary=") {
        hash_data(regsub(req.http.cookie, "^.*?X-Magento-Vary=([^;]+);*.*$", "\1"));
    } else {
        hash_data("");
    }
    
    # Create cache variations depending on the request protocol
    hash_data(req.http.X-Forwarded-Proto);

    # Create store and currency cache variations for GraphQL requests
    if (req.url ~ "/graphql") {
        hash_data(req.http.Store);
        hash_data(req.http.Content-Currency);
    }
}

sub vcl_backend_response {
    # Serve stale content for three days after object expiration
    # Perform asynchronous revalidation while stale content is served
    set beresp.grace = 3d;

    # All text-based content can be parsed as ESI
    if (beresp.http.content-type ~ "text") {
        set beresp.do_esi = true;
    }

    # Allow GZIP compression on all JavaScript files and all text-based content
    if (bereq.url ~ "\.js$" || beresp.http.content-type ~ "text") {
        set beresp.do_gzip = true;
    }
    
    # Add debug headers
    if (beresp.http.X-Magento-Debug) {
        set beresp.http.X-Magento-Cache-Control = beresp.http.Cache-Control;
    }

    # Only cache HTTP 200 & HTTP 404 responses
    if (beresp.status != 200 && beresp.status != 404) {
        set beresp.ttl = 120s;
        set beresp.uncacheable = true;
        return (deliver);
    # Don't cache private responses
    } elsif (beresp.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        set beresp.ttl = 86400s;
        return (deliver);
    }

    # Remove the Set-Cookie header for cacheable content
    # Only for HTTP GET & HTTP HEAD requests
    if (beresp.ttl > 0s && (bereq.method == "GET" || bereq.method == "HEAD")) {
        unset beresp.http.set-cookie;
    }
   
    # Don't cache content with a negative TTL
    # Don't cache content for no-cache or no-store content
    # Don't cache content where all headers are varied
    if (beresp.ttl <= 0s ||
       beresp.http.Surrogate-control ~ "no-store" ||
       (!beresp.http.Surrogate-Control &&
       beresp.http.Cache-Control ~ "no-cache|no-store") ||
       beresp.http.Vary == "*") {
        set beresp.ttl = 120s;
        set beresp.uncacheable = true;
    }

    return (deliver);
}

sub vcl_deliver {
    # Add debug headers
    if (resp.http.X-Magento-Debug) {
        if (obj.uncacheable) {
            set resp.http.X-Magento-Cache-Debug = "UNCACHEABLE";
        } else if (obj.hits) {
            set resp.http.X-Magento-Cache-Debug = "HIT";
            set resp.http.Grace = req.http.grace;
        } else {
            set resp.http.X-Magento-Cache-Debug = "MISS";
        }
    } else {
        unset resp.http.Age;
    }

    # Don't let browser cache non-static files
    if (resp.http.Cache-Control !~ "private" && req.url !~ "^/(pub/)?(media|static)/") {
        set resp.http.Pragma = "no-cache";
        set resp.http.Expires = "-1";
        set resp.http.Cache-Control = "no-store, no-cache, must-revalidate, max-age=0";
    }
    
    # Cleanup headers
    unset resp.http.X-Magento-Debug;
    unset resp.http.X-Magento-Tags;
    unset resp.http.X-Powered-By;
    unset resp.http.Server;
    unset resp.http.X-Varnish;
    unset resp.http.Via;
    unset resp.http.Link;
}

So please help me with which file I should use to get the maximum caching.

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2 Answers 2

Reset to default
1

I wrote the Official Varnish Magento VCL file that you found on https://www.varnish-software.com/developers/tutorials/configuring-varnish-magento/#optimized-magento-vcl-file.

While you are free to use the one provided by Magento, our version is optimized and has slightly less complexity.

  • We removed some lines from the VCL that made no sense
  • The request sanitization was improved
  • We also overhauled the grace handling, which is Varnish's take on stale-while-revalidate
  • There is better TLS awareness in our Magento VCL

And there are some other minor improvements.

Maybe at some point Magento can use our improved version, but for the time being you can choose which ever version you want.

While I'm convinced that our version is slightly optimized, there's no guarantee you'll experience better performance. It just covers some edge cases better.

Hope that helps. If you have specific questions about the implementation, don't hesitate to contact me or to post a specific question on StackOverflow.

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4
  • Thank you so much for helping us with such a contribution, I really appreciate your effort and also your answer. Still, the question is: Is your optimized version compatible with all currently supported versions? please forgive me if it is a naive question as I'm a beginner at Varnish.
    – AboElnouR
    Commented Jul 16, 2022 at 0:56
  • 1
    @AboElnouR It should be compatibel with the currently supported versions, yes. It's actually based on the standard Magento 2 VCL file, so the support is there by design.
    – Thijs Feryn
    Commented Jul 18, 2022 at 7:29
  • @ThijsFeryn - I am using Magento 2.4 with varnish but my admin is getting cached, can you please suggest something to bypass all admin requests.
    – Ram Sharma
    Commented Mar 21, 2023 at 14:48
  • 1
    @RamSharma please open up a separate question for that and I'll look into it. Please provide enough context of what is going wrong. Please also include the response headers that admin pages are returning, because by default the Magento admin is not cached. So something must be wrong.
    – Thijs Feryn
    Commented Mar 22, 2023 at 8:19
1

Diff the two .vcl versions that you have and compare the differences. You will see that apart from some comments there are not that many changes.

Personally I would go with the supplied vcl file from the Magento package.

Depending on your Magento version the one issue you must be aware of is the location of health_check.php which in versions of Magento before 2.4 was in /pub/. This must be correct or the health check will fail.

The probe that performs the health checks will return HTTP 404 errors and as a consequence Varnish will return HTTP 503 Backend fetch failed errors because it considers the backend to be unhealthy.

backend default {
    .host = "localhost";
    .port = "8080";
    .first_byte_timeout = 600s;
    .probe = {
        .url = "/health_check.php";
        .timeout = 2s;
        .interval = 5s;
        .window = 10;
        .threshold = 5;
   }
}
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