Error 502, "no live upstreams while connecting to upstream" how to solve

manavkalra15

Hello,

My website is created on wordpress. I am using Wordops latest version.

Sometimes it shows 502 error when try to access my website different pages.

When I checked error logs I found this

`2022/09/11 05:55:26 [error] 574#574: *77250 no live upstreams while connecting to upstream, client: 66.249.70.124, server: domain.com, request: "GET /url/ HTTP/1.1", upstream: "fastcgi://php80", host: "www.domain.com"

2022/09/11 05:58:51 [error] 1211#1211: *42 upstream sent invalid header: "Plugin\x20..." while reading response header from upstream, client: 23.97.246.209, server: domain.com, request: "POST /wp-login.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php80-two-fpm.sock:", host: "domain.com"

2022/09/11 05:59:50 [error] 1212#1212: *109 upstream sent invalid header: "Plugin\x20..." while reading response header from upstream, client: 66.249.70.122, server:domain.com, request: "GET /url/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php80-fpm.sock:", host: "www.domain.com"`

Please tell me how to solve this error.

portofacil

Perhaps your server hasn't enough resources to handle the requests. How much RAM and CPU does it have?

Also, are you using cache on your site?

manavkalra15

Ram - 8 GB
CPU - 4 vCPU

No , I am not using cache on my websites.

I added "max_fails=3 fail_timeout=30s" to upstream.conf file now "no live upstreams while connecting to upstream" this error not coming but this error is coming upstream sent invalid header: "Plugin\x20..." while reading response header from upstream

I Found this in error log
`2022/09/11 10:15:43 [error] 14228#14228: *374 upstream sent invalid header: "Plugin\x20..." while reading response header from upstream, client: 40.77.167.45, server: DOMAIN.COM, request: "GET /URL-OF-PAGE/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php80-fpm.sock:", host: "WWW.DOMAIN.COM"

2022/09/11 10:17:20 [error] 14229#14229: *37 upstream sent invalid header: "Plugin\x20..." while reading response header from upstream, client: 192.95.30.71, server😃OMAIN.COM, request: "GET /URL-OF-PAGE/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php80-two-fpm.sock:", host: "WWW.DOMAIN.COM"

2022/09/11 10:18:41 [error] 14228#14228: *565 upstream sent invalid header: "Plugin\x20..." while reading response header from upstream, client: 40.77.167.11, server: lyricsdone.com, request: "GET /URL-OF-PAGE/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php80-two-fpm.sock:", host: "WWW.DOMAIN.COM"

2022/09/11 10:18:50 [error] 14228#14228: *578 upstream sent invalid header: "Plugin\x20..." while reading response header from upstream, client: 207.46.13.51, server: lyricsdone.com, request: "GET /URL-OF-PAGE/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php80-two-fpm.sock:", host: "WWW.DOMAIN.COM"`

Please tell me how to solve this error.

portofacil

Try disabling all plugins and switching to a standard WP theme. If the error stops, then you'll know it's something in your code.

This is not a default behavior of Nginx, WordOps or even WordPress. You have to try and investigate your own blog.

manavkalra15

Will this issue cause any problems on the front end of the site? Or in google crawling?

portofacil

I don't think I'm capable to understand your question. Let's hope someone else can help.