I got 502 and error_log print upstream sent invalid status "0"

Server NGINX
1

Hi everyone,

I have a php-fpm backend. And sometimes I got nginx return 502. After I
check the error_log I found each 502s are caused by upstream sent
invalid status “0” while reading response header from upstream

The error_log are in the form “upstream sent invalid status “0” while
reading response header from upstream client: 127.0.0.1, server: xxxx,
request: “xxxxx HTTP/1.0”, upstream:
“fastcgi://unix:/dev/shm/api-php.socket:”, host: “xxxx”, referrer:
“xxxx””

Does anyone have same experience? I have no idea after search Google
‘upstream sent invalid status “0”’

I think it is caused by PHP. But why does it sent status ‘0’?

Yours Sincerely.

Posted at Nginx Forum:

2

Hello!

On Thu, Mar 29, 2012 at 11:14:46PM -0400, neoesque wrote:

“xxxx”"

Does anyone have same experience? I have no idea after search Google
‘upstream sent invalid status “0”’

I think it is caused by PHP. But why does it sent status ‘0’?

The message in question means nginx got header line “Status: 0”
from php. Most likely it’s what you php code did, not php by
itself.

Maxim D.

3

Hi, Maxim

Thanks, I’ll check those PHP codes.

Posted at Nginx Forum:

4

OH!

You are right, Maxim.

Those errors are retrieving other webpage by using curl. And the
upstreams return status code 0 seldomly.

Thank you.

Posted at Nginx Forum: