We have a Magento 2.4.0 store. Most of our products are configurable. And some of them are having a lot of options. We also use swatch options.
We have discovered some links which return:
Error 503 Backend fetch failed
Backend fetch failed
Guru Meditation:
XID: 56884378
Varnish cache server
My Nginx configuration file:
autoindex off;
sendfile on;
tcp_nodelay on;
keepalive_timeout 25;
client_body_timeout 15;
client_header_timeout 15;
send_timeout 15;
types_hash_max_size 2048;
server_tokens off;
client_max_body_size 64M;
client_body_buffer_size 128k;
client_header_buffer_size 16k;
large_client_header_buffers 4 16k;
fastcgi_read_timeout 300;
proxy_read_timeout 300;
fastcgi_buffer_size 256k;
fastcgi_buffers 16 256k;
open_file_cache max=50000 inactive=30s;
open_file_cache_valid 30s;
open_file_cache_min_uses 2;
gzip on;
gzip_vary on;
gzip_disable "MSIE [1-6]\.";
gzip_static on;
gzip_min_length 1400;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_comp_level 6;
gzip_proxied any;
gzip_types text/plain text/css text/xml application/javascript application/x-javascript application/xml application/xml+rss application/ecmascript application/json image/svg+xml ;
My vhost file:
fastcgi_index index.php;
fastcgi_pass golfcoukbackend;
fastcgi_buffers 16 256k;
fastcgi_buffer_size 256k;
fastcgi_read_timeout 600s;
fastcgi_connect_timeout 600s;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
location ~* .(ico|jpg|jpeg|png|gif|svg|js|css|swf|eot|ttf|otf|woff|woff2)$ {
add_header Cache-Control "public";
add_header X-Frame-Options "SAMEORIGIN";
expires +1y;
}
}
Nginx seems that does not have the issue.
Varnish default.vcl file:
# Varnish configuration
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 = "10.2.37.9";
.port = "8080";
.first_byte_timeout = 600s;
# .probe = {
# .url = "/health_check.php";
# .timeout = 2s;
# .interval = 5s;
# .window = 10;
# .threshold = 5;
# }
}
acl purge {
"127.0.0.1";
"myip";
"10.2.37.9";
}
sub vcl_recv {
# For multiple backends, uncomment the below. Ensure you are using the right
# selection code depending on the type of loadbalancing being used.
# set req.backend_hint = prod_web.backend();
# Remove this if using multiple backends.
set req.backend_hint = default;
# To Exclude a Domain uncomment the below
#if (req.http.host ~ "exampledomain.com") {
#return (pass);
#}
if (req.restarts > 0) {
set req.hash_always_miss = true;
}
# Exclude domain example
if (req.http.host ~ "exampledomain.com") {
return (pass);
}
# Exclude URI example
if (req.url ~ "^/.well-known/") {
return (pass);
}
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 its 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);
}
# ban everything to catch assets as well
if (req.http.X-Magento-Tags-Pattern == ".*") {
ban("req.url ~ .*");
}
if (req.http.X-Pool) {
ban("obj.http.X-Pool ~ " + req.http.X-Pool);
}
return (synth(200, "Purged"));
}
# HTTP -> HTTPS
if (req.http.X-Forwarded-Proto !~ "https") {
set req.http.location = "https://" + req.http.host + req.url;
return (synth(750, "Permanently moved"));
}
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 shopping cart, checkout and search requests
if (req.url ~ "/checkout" || req.url ~ "/catalogsearch") {
return (pass);
}
# Bypass health check requests
if (req.url ~ "/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;
}
return (hash);
}
sub vcl_hash {
if (req.http.cookie ~ "X-Magento-Vary=") {
hash_data(regsub(req.http.cookie, "^.*?X-Magento-Vary=([^;]+);*.*$", "\1"));
}
# For multi site configurations to not cache each other's content
if (req.http.host) {
hash_data(req.http.host);
} else {
hash_data(server.ip);
}
# To make sure http users don't see ssl warning
if (req.http.X-Forwarded-Proto) {
hash_data(req.http.X-Forwarded-Proto);
}
if (req.url ~ "/graphql") {
call process_graphql_headers;
}
}
sub process_graphql_headers {
if (req.http.Store) {
hash_data(req.http.Store);
}
if (req.http.Content-Currency) {
hash_data(req.http.Content-Currency);
}
}
sub vcl_backend_response {
set beresp.grace = 3d;
if (beresp.http.content-type ~ "text") {
set beresp.do_esi = true;
}
if (bereq.url ~ "\.js$" || 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
if (beresp.status != 200 && beresp.status != 404) {
set beresp.ttl = 0s;
set beresp.uncacheable = true;
return (deliver);
} elsif (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;
}
return (deliver);
}
sub vcl_deliver {
if (resp.http.X-Magento-Debug) {
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";
}
} else {
unset resp.http.Age;
}
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";
}
# 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";
}
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_synth {
if (resp.status == 750) {
set resp.http.location = req.http.location;
set resp.status = 301;
return (deliver);
}
}
#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);
# }
#}
Varnish runs with default hdr_len
If I am right our issue is related to the Magento 2 bug with configurable products and big headers which are coming when there are configurable products with a lot of variations.
https://github.com/magento/magento2/issues/23834
I have tried a solution described in the above link which disables plugin product_identities_extender. This fixes the problem but not in all our products...
Some still return Backend fetch failed
varnishlog -g request -q "ReqUrl ~ '^/masters-rain'" output:
<< Request >> 4121486
Begin req 4121485 rxreq
Timestamp Start: 1637777394.195388 0.000000 0.000000
Timestamp Req: 1637777394.195388 0.000000 0.000000
VCL_use boot
ReqStart 10.2.37.9 60676 a0
ReqMethod GET
ReqURL /masters-rain-wedge-bag-cover
ReqProtocol HTTP/1.0
ReqHeader X-Real-IP: my.ip
ReqHeader X-Forwarded-For: my.ip
ReqHeader X-Forwarded-Proto: https
ReqHeader X-Forwarded-Port: 443
ReqHeader Host: www.example.co.uk
ReqHeader Connection: close
ReqHeader accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
ReqHeader user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.1 Safari/605.1.15
ReqHeader accept-language: en-GB,en;q=0.9
ReqHeader accept-encoding: gzip, deflate, br
ReqHeader cookie: _dc_gtm_UA-example-1=1; _ga=GA1.3.1098407753.1637181974; _gid=GA1.3.734412942.1637623269; PHPSESSID=e9pbvu084k13675ka6vpkukdp2; form_key=2qfq1dIqSyhkL8ho; form_key=2qfq1dIqSyhkL8ho; mage-cache-sessid=true; mage-messages=; section_data_ids=%7B%22
ReqUnset X-Forwarded-For: my.ip
ReqHeader X-Forwarded-For: my.ip, 10.2.37.9
VCL_call RECV
ReqHeader grace: none
ReqURL /masters-rain-wedge-bag-cover
ReqUnset accept-encoding: gzip, deflate, br
ReqHeader Accept-Encoding: gzip
VCL_return hash
VCL_call HASH
VCL_return lookup
VCL_call MISS
VCL_return fetch
Link bereq 4121487 fetch
Timestamp Fetch: 1637777397.649357 3.453968 3.453968
RespProtocol HTTP/1.1
RespStatus 200
RespReason OK
RespHeader Server: nginx
RespHeader Date: Wed, 24 Nov 2021 18:09:57 GMT
RespHeader Content-Type: text/html; charset=UTF-8
RespHeader Pragma: cache
RespHeader Cache-Control: max-age=86400, public, s-maxage=86400
RespHeader Expires: Thu, 25 Nov 2021 18:09:54 GMT
RespHeader ALEX-TEST-HEADER: 37230
RespHeader X-Magento-Tags:
RespHeader X-Content-Type-Options: nosniff
RespHeader X-XSS-Protection: 1; mode=block
RespHeader X-Frame-Options: SAMEORIGIN
RespHeader Vary: Accept-Encoding
RespHeader Content-Encoding: gzip
RespHeader X-Varnish: 4121486
RespHeader Age: 0
RespHeader Via: 1.1 varnish (Varnish/6.5)
VCL_call DELIVER
RespUnset Age: 0
RespHeader X-Cache: MISS
RespUnset Pragma: cache
RespHeader Pragma: no-cache
RespUnset Expires: Thu, 25 Nov 2021 18:09:54 GMT
RespHeader Expires: -1
RespUnset Cache-Control: max-age=86400, public, s-maxage=86400
RespHeader Cache-Control: no-store, no-cache, must-revalidate, max-age=0
RespUnset X-Magento-Tags:
RespUnset Server: nginx
RespUnset X-Varnish: 4121486
RespUnset Via: 1.1 varnish (Varnish/6.5)
VCL_return deliver
Timestamp Process: 1637777397.649415 3.454027 0.000058
Filters
RespHeader Accept-Ranges: bytes
RespHeader Content-Length: 22193
RespHeader Connection: close
Timestamp Resp: 1637777397.649481 3.454092 0.000065
ReqAcct 1133 0 1133 436 22193 22629
End
<< BeReq >> 4121487
Begin bereq 4121486 fetch
VCL_use boot
Timestamp Start: 1637777394.195457 0.000000 0.000000
BereqMethod GET
BereqURL /masters-rain-wedge-bag-cover
BereqProtocol HTTP/1.0
BereqHeader X-Real-IP: my.ip
BereqHeader X-Forwarded-Proto: https
BereqHeader X-Forwarded-Port: 443
BereqHeader Host: www.example.co.uk
BereqHeader accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
BereqHeader user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.1 Safari/605.1.15
BereqHeader accept-language: en-GB,en;q=0.9
BereqHeader cookie: _dc_gtm_UA-70723715-1=1; _ga=GA1.3.1098407753.1637181974; _gid=GA1.3.734412942.1637623269; PHPSESSID=e9pbvu084k13675ka6vpkukdp2; form_key=2qfq1dIqSyhkL8ho; form_key=2qfq1dIqSyhkL8ho; mage-cache-sessid=true; mage-messages=; section_data_ids=%7B%22
BereqHeader X-Forwarded-For: my.ip, 10.2.37.9
BereqHeader grace: none
BereqHeader Accept-Encoding: gzip
BereqProtocol HTTP/1.1
BereqHeader X-Varnish: 4121487
VCL_call BACKEND_FETCH
VCL_return fetch
BackendOpen 60 default 10.2.37.9 8080 10.2.37.9 48270 reuse
Timestamp Bereq: 1637777394.195563 0.000105 0.000105
Timestamp Beresp: 1637777397.638441 3.442983 3.442878
BerespProtocol HTTP/1.1
BerespStatus 200
BerespReason OK
BerespHeader Server: nginx
BerespHeader Date: Wed, 24 Nov 2021 18:09:57 GMT
BerespHeader Content-Type: text/html; charset=UTF-8
BerespHeader Transfer-Encoding: chunked
BerespHeader Connection: keep-alive
BerespHeader Set-Cookie: form_key=2qfq1dIqSyhkL8ho; expires=Wed, 24-Nov-2021 19:09:54 GMT; Max-Age=3600; path=/; domain=www.example.co.uk; secure
BerespHeader Set-Cookie: PHPSESSID=e9pbvu084k13675ka6vpkukdp2; expires=Wed, 24-Nov-2021 19:09:54 GMT; Max-Age=3600; path=/; domain=www.example.co.uk; secure; HttpOnly
BerespHeader Set-Cookie: PHPSESSID=e9pbvu084k13675ka6vpkukdp2; expires=Wed, 24-Nov-2021 19:09:54 GMT; Max-Age=3600; path=/; domain=www.example.co.uk; secure; HttpOnly
BerespHeader Pragma: cache
BerespHeader Cache-Control: max-age=86400, public, s-maxage=86400
BerespHeader Expires: Thu, 25 Nov 2021 18:09:54 GMT
BerespHeader ALEX-TEST-HEADER: 37230
BerespHeader X-Magento-Tags:
BerespHeader X-Content-Type-Options: nosniff
BerespHeader X-XSS-Protection: 1; mode=block
BerespHeader X-Frame-Options: SAMEORIGIN
BerespHeader Content-Encoding: gzip
BerespHeader Vary: Accept-Encoding
TTL RFC 86400 10 0 1637777398 1637777398 1637777397 1637863794 86400 cacheable
VCL_call BACKEND_RESPONSE
TTL VCL 86400 259200 0 1637777398 cacheable
BerespUnset Set-Cookie: form_key=2qfq1dIqSyhkL8ho; expires=Wed, 24-Nov-2021 19:09:54 GMT; Max-Age=3600; path=/; domain=www.example.co.uk; secure
BerespUnset Set-Cookie: PHPSESSID=e9pbvu084k13675ka6vpkukdp2; expires=Wed, 24-Nov-2021 19:09:54 GMT; Max-Age=3600; path=/; domain=www.example.co.uk; secure; HttpOnly
BerespUnset Set-Cookie: PHPSESSID=e9pbvu084k13675ka6vpkukdp2; expires=Wed, 24-Nov-2021 19:09:54 GMT; Max-Age=3600; path=/; domain=www.example.co.uk; secure; HttpOnly
VCL_return deliver
Filters gunzip esi_gzip
BerespUnset Content-Encoding: gzip
BerespHeader Content-Encoding: gzip
Storage malloc s0
Fetch_Body 2 chunked -
Gzip G F E 108872 22193 80 177464 177474
Gzip U F - 22188 108872 80 177424 177434
BackendClose 60 default recycle
Timestamp BerespBody: 1637777397.649352 3.453894 0.010910
Length 22193
BereqAcct 1145 0 1145 916 0 916
End
Any help please? I am at a dead-end here!