I have installed a fresh copy of Magento 2 (2.3.5 with sample data) on a VPS which has the following stack: Ubuntu 18.04, Nginx, Mysql, and PHP 7.2 FPM.
This vanilla installation worked.
However, after enabling Varnish cache on Magento 2, some of the pages on the website are now displaying an Error 502 bad gateway message.
I have tried days troubleshooting this issue, without any luck. This is a fresh installation of Magneto 2, using the sample data.
I have come across a few posts online which suggest to increase the proxy_buffer_size within the server block of the nginx configuration file. However, this has not worked in my case and I am still receiving a 502 error on some of the links on the Magneto website.
Does anybody know how I could go about resolving this issue and get Varnish working?
I appreciate any help that you could provide. I have provided below the configuration files, logs, and setup information for Nginx, Varnish, and VPS setup.
Nginx host configuration file:
upstream fastcgi_backend {
server unix:/run/php/php7.2-fpm.sock;
}
server {
server_name www.example.com;
return 301 https://example.com$request_uri;
}
server {
listen 80;
listen [::]:80;
server_name example.com;
return 301 https://$server_name$request_uri;
}
server {
listen 443 ssl http2;
server_name www.example.com;
return 301 https://example.com$request_uri;
ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
}
server {
listen 443 ssl http2;
server_name example.com;
access_log /var/log/nginx/example.com-access.log;
error_log /var/log/nginx/example.com-error.log;
ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 24h;
keepalive_timeout 300s;
# OCSP stapling
ssl_stapling on;
ssl_stapling_verify on;
# HSTS (ngx_http_headers_module is required) (63072000 seconds)
add_header Strict-Transport-Security "max-age=63072000" always;
location / {
proxy_pass http://127.0.0.1:6081;
proxy_set_header Host $http_host;
proxy_set_header X-Forwarded-Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Ssl-Offloaded "1";
proxy_set_header X-Forwarded-Proto https;
proxy_set_header X-Forwarded-Port 443;
proxy_redirect http://example.com:8080/ /;
proxy_http_version 1.1;
proxy_buffer_size 256k;
proxy_buffers 4 256k;
proxy_busy_buffers_size 256k;
}
}
server {
server_name example.com;
listen 127.0.0.1:8080;
set $MAGE_ROOT /var/www/example.com/html;
include /var/www/example.com/html/nginx.conf.sample;
}
Magento/default vcl config:
root@ubuntu-8gb-nbg1-1:/etc/varnish# cat default.vcl
# VCL version 5.0 is not supported so it should be 4.0 even though actually used Varnish version is 5
vcl 4.0;
import std;
# The minimal Varnish version is 5.0
# 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";
.url = "/health_check.php";
.timeout = 2s;
.interval = 5s;
.window = 10;
.threshold = 5;
}
}
acl purge {
"localhost";
}
sub vcl_recv {
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 shopping cart, checkout and search requests
if (req.url ~ "/checkout" || req.url ~ "/catalogsearch") {
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, "[?|&]+$", "");
}
# Static files caching
if (req.url ~ "^/(pub/)?(media|static)/") {
# Static files should not be cached by default
return (pass);
# But if you use a few locales and don't use CDN you can enable caching static files by commenting previous line (#return (pass);) and uncommenting next 3 lines
#unset req.http.Https;
#unset req.http.X-Forwarded-Proto;
#unset req.http.Cookie;
}
return (hash);
}
sub vcl_hash {
if (req.http.cookie ~ "X-Magento-Vary=") {
hash_data(regsub(req.http.cookie, "^.*?X-Magento-Vary=([^;]+);*.*$", "\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) {
# 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 (miss);
}
} else {
# server is not healthy, retrieve from cache
set req.http.grace = "unlimited (unhealthy server)";
return (deliver);
}
}
Error log from /var/log/nginx/error.log:
root@ubuntu-8gb-nbg1-1:/var/log/nginx#
2020/06/18 20:20:03 [error] 20205#20205: *1375 upstream sent too big header while reading response header from upstream, client: 127.0.0.1, server: example.com, request: "GET /men/tops-men/jackets-men.html HTTP/1.1", upstream: "fastcgi://unix:/run/php/php7.2-fpm.sock:", host: "example.com", referrer: "https://example.com/what-is-new.html"
Varnish live log:
root@ubuntu-8gb-nbg1-1:/var/log/nginx# varnishlog
- << BeReq >> 32841
- Begin bereq 32840 fetch
- Timestamp Start: 1592504403.501162 0.000000 0.000000
- BereqMethod GET
- BereqURL /men/tops-men/jackets-men.html
- BereqProtocol HTTP/1.1
- BereqHeader Host: example.com
- BereqHeader X-Forwarded-Host: example.com
- BereqHeader X-Real-IP: x.x.x.x
- BereqHeader Ssl-Offloaded: 1
- BereqHeader X-Forwarded-Proto: https
- BereqHeader X-Forwarded-Port: 443
- BereqHeader CF-IPCountry: GB
- BereqHeader CF-RAY: 5a5705a789e73669-MAN
- BereqHeader CF-Visitor: {"scheme":"https"}
- BereqHeader user-agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0
- BereqHeader accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,/;q=0.8
- BereqHeader accept-language: en-GB,en;q=0.5
- BereqHeader dnt: 1
- BereqHeader referer: https://example.com/what-is-new.html
- BereqHeader upgrade-insecure-requests: 1
- BereqHeader cookie: __cfduid=d6e220d7c9b748b1fc0725cfa4138edce1592497645; mage-cache-storage=%7B%7D; mage-cache-storage-section-invalidation=%7B%7D; mage-cache-sessid=true; mage-messages=; recently_viewed_product=%7B%7D; recently_viewed_product_previous=%7B%7D; rece
- BereqHeader CF-Request-ID: 036a41dcb500003669378e9200000001
- BereqHeader CF-Connecting-IP: x.x.x.x
- BereqHeader CDN-Loop: cloudflare
- BereqHeader X-Forwarded-For: x.x.x.x, x.x.x.x, 127.0.0.1
- BereqHeader grace: none
- BereqHeader Accept-Encoding: gzip
- BereqHeader X-Varnish: 32841
- VCL_call BACKEND_FETCH
- VCL_return fetch
- BackendOpen 25 boot.default 127.0.0.1 8080 127.0.0.1 48908
- BackendStart 127.0.0.1 8080
- Timestamp Bereq: 1592504403.501272 0.000110 0.000110
- Timestamp Beresp: 1592504403.791456 0.290293 0.290183
- BerespProtocol HTTP/1.1
- BerespStatus 502
- BerespReason Bad Gateway
- BerespHeader Server: nginx/1.14.0 (Ubuntu)
- BerespHeader Date: Thu, 18 Jun 2020 18:20:03 GMT
- BerespHeader Content-Type: text/html; charset=UTF-8
- BerespHeader Content-Length: 182
- BerespHeader Connection: keep-alive
- TTL RFC -1 10 0 1592504404 1592504404 1592504403 0 0
- VCL_call BACKEND_RESPONSE
- TTL VCL -1 259200 0 1592504404
- TTL VCL 0 259200 0 1592504404
- VCL_return deliver
- BerespUnset Content-Length: 182
- BerespHeader Content-Encoding: gzip
- BerespHeader Vary: Accept-Encoding
- Storage malloc Transient
- ObjProtocol HTTP/1.1
- ObjStatus 502
- ObjReason Bad Gateway
- ObjHeader Server: nginx/1.14.0 (Ubuntu)
- ObjHeader Date: Thu, 18 Jun 2020 18:20:03 GMT
- ObjHeader Content-Type: text/html; charset=UTF-8
- ObjHeader Content-Encoding: gzip
- ObjHeader Vary: Accept-Encoding
- Fetch_Body 3 length -
- Gzip G F E 182 153 80 1144 1154
- BackendReuse 25 boot.default
- Timestamp BerespBody: 1592504403.791677 0.290515 0.000221
- Length 153
- BereqAcct 1164 0 1164 181 0 181
- End
- << Request >> 32840
- Begin req 32839 rxreq
- Timestamp Start: 1592504403.501053 0.000000 0.000000
- Timestamp Req: 1592504403.501053 0.000000 0.000000
- ReqStart 127.0.0.1 49160
- ReqMethod GET
- ReqURL /men/tops-men/jackets-men.html
- ReqProtocol HTTP/1.1
- ReqHeader Host: example.com
- ReqHeader X-Forwarded-Host: example.com
- ReqHeader X-Real-IP: x.x.x.x
- ReqHeader X-Forwarded-For: x.x.x.x, x.x.x.x
- ReqHeader Ssl-Offloaded: 1
- ReqHeader X-Forwarded-Proto: https
- ReqHeader X-Forwarded-Port: 443
- ReqHeader Connection: close
- ReqHeader Accept-Encoding: gzip
- ReqHeader CF-IPCountry: GB
- ReqHeader CF-RAY: 5a5705a789e73669-MAN
- ReqHeader CF-Visitor: {"scheme":"https"}
- ReqHeader user-agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0
- ReqHeader accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,/;q=0.8
- ReqHeader accept-language: en-GB,en;q=0.5
- ReqHeader dnt: 1
- ReqHeader referer: https://example.com/what-is-new.html
- ReqHeader upgrade-insecure-requests: 1
- ReqHeader cookie: __cfduid=d6e220d7c9b748b1fc0725cfa4138edce1592497645; mage-cache-storage=%7B%7D; mage-cache-storage-section-invalidation=%7B%7D; mage-cache-sessid=true; mage-messages=; recently_viewed_product=%7B%7D; recently_viewed_product_previous=%7B%7D; rece
- ReqHeader CF-Request-ID: 036a41dcb500003669378e9200000001
- ReqHeader CF-Connecting-IP: x.x.x.x
- ReqHeader CDN-Loop: cloudflare
- ReqUnset X-Forwarded-For: x.x.x.x, x.x.x.x
- ReqHeader X-Forwarded-For: x.x.x.x, x.x.x.x, 127.0.0.1
- VCL_call RECV
- ReqHeader grace: none
- ReqURL /men/tops-men/jackets-men.html
- ReqUnset Accept-Encoding: gzip
- ReqHeader Accept-Encoding: gzip
- VCL_return hash
- VCL_call HASH
- VCL_return lookup
- VCL_call MISS
- VCL_return fetch
- Link bereq 32841 fetch
- Timestamp Fetch: 1592504403.791718 0.290665 0.290665
- RespProtocol HTTP/1.1
- RespStatus 502
- RespReason Bad Gateway
- RespHeader Server: nginx/1.14.0 (Ubuntu)
- RespHeader Date: Thu, 18 Jun 2020 18:20:03 GMT
- RespHeader Content-Type: text/html; charset=UTF-8
- RespHeader Content-Encoding: gzip
- RespHeader Vary: Accept-Encoding
- RespHeader X-Varnish: 32840
- RespHeader Age: 0
- RespHeader Via: 1.1 varnish (Varnish/5.2)
- VCL_call DELIVER
- RespUnset Age: 0
- RespHeader Pragma: no-cache
- RespHeader Expires: -1
- RespHeader Cache-Control: no-store, no-cache, must-revalidate, max-age=0
- RespUnset Server: nginx/1.14.0 (Ubuntu)
- RespUnset X-Varnish: 32840
- RespUnset Via: 1.1 varnish (Varnish/5.2)
- VCL_return deliver
- Timestamp Process: 1592504403.791760 0.290707 0.000041
- RespHeader Content-Length: 153
- RespHeader Connection: close
- Timestamp Resp: 1592504403.791802 0.290749 0.000042
- ReqAcct 1141 0 1141 286 153 439
- End
- << Session >> 32839
- Begin sess 0 HTTP/1
- SessOpen 127.0.0.1 49160 a0 127.0.0.1 6081 1592504403.501004 22
- Link req 32840 rxreq
- SessClose REQ_CLOSE 0.291
- End
netstat output:
root@ubuntu-8gb-nbg1-1:/etc/nginx/sites-available# netstat -plntu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:6081 0.0.0.0:* LISTEN 19887/varnishd
tcp 0 0 127.0.0.1:6082 0.0.0.0:* LISTEN 19887/varnishd
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 870/mysqld
tcp 0 0 x.x.x.x:2222 0.0.0.0:* LISTEN 7853/sshd
tcp 0 0 127.0.0.1:8080 0.0.0.0:* LISTEN 20204/nginx: master
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 20204/nginx: master
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN 18327/systemd-resol
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 20204/nginx: master
tcp6 0 0 :::6081 :::* LISTEN 19887/varnishd
tcp6 0 0 :::80 :::* LISTEN 20204/nginx: master
udp 0 0 127.0.0.53:53 0.0.0.0:* 18327/systemd-resol
udp 0 0 0.0.0.0:68 0.0.0.0:*
