nginx big header response - facebook

Question

"upstream sent too big header while reading response header from upstream"
I keep getting this when I try and do an authentication from facebook. I've increased my buffers:
proxy_buffer_size 256k;
proxy_buffers 8 256k;
proxy_busy_buffers_size 512k;
fastcgi_buffers 8 256k;
fastcgi_buffer_size 128k;
But it doesn't seem to help. Any thoughts as to why this might occur?
nginx.conf file:
user www-data;
worker_processes 1;
error_log /var/log/nginx/error.log;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
# multi_accept on;
}
http {
include /etc/nginx/mime.types;
proxy_buffer_size 256k;
proxy_buffers 8 256k;
proxy_busy_buffers_size 512k;
fastcgi_buffers 8 256k;
fastcgi_buffer_size 128k;
access_log /var/log/nginx/access.log;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
tcp_nodelay on;
gzip on;
gzip_disable "MSIE [1-6]\.(?!.*SV1)";
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}
/etc/nginx/sites-enabled/default
server {
listen 80 default;
server_name localhost;
access_log /var/log/nginx/localhost.access.log;
location / {
root /var/www/nginx-default;
index index.html index.htm;
}
location /doc {
root /usr/share;
autoindex on;
allow 127.0.0.1;
deny all;
}
location /images {
root /usr/share;
autoindex on;
}
}

Answer 1

In codeigniter I had the same error. This works for me:
http://forum.nginx.org/read.php?2,192785,196003#msg-196003
In .conf
location ~* \.php$ {
fastcgi_pass 127.0.0.1:9001;
fastcgi_index index.php;
fastcgi_split_path_info ^(.+\.php)(.*)$;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
# 16-sept-2012 parametros para evitar el 502
fastcgi_temp_file_write_size 10m;
fastcgi_busy_buffers_size 512k;
fastcgi_buffer_size 512k;
fastcgi_buffers 16 512k;
fastcgi_connect_timeout 300;
fastcgi_send_timeout 300;
fastcgi_read_timeout 300;
fastcgi_intercept_errors on;
fastcgi_next_upstream error invalid_header timeout http_500;
}

Answer 2

I had the same exact issue this morning. However, increasing buffer size worked for me. This is the settings that I used:
proxy_buffer_size 128k;
proxy_buffers 4 256k;
proxy_busy_buffers_size 256k;
proxy_temp_file_write_size 256k;
The only setting I don't see in your config is
proxy_temp_file_write_size 256k;
Also, I added these values just for that vhost. I don't think it should matter, but might be worth trying.

Answer 3

Turns out Codeigniter sets its own max size. I haven't figured out how to limit that, but changing nginx won't change anything unfortunately. Thanks for all the help VBart and gsharma.

Answer 4

We are moving our production environment and the old one works without problem and had the same "upstream sent too big header while reading response header from upstream" problem. This is a Codeigniter 2.x application.
Like #gsharma said, after change the server config with this the error log disappeared.
fastcgi_buffers 256 4k;
fastcgi_buffer_size 8k;
However, still had some problems: login did'n work anymore.
The problem was around $config['sess_encrypt_cookie']=TRUE;
When using sess_encrypt_cookie, Codeigniter tries to use mcrypt library but if it doesn't exist uses a method called '_xor_encode'. Ok, I think this method it's buggy.
After install php-mcrypt everything worked without problems.
(sorry for my english)

Answer 5

I am getting this error, on a page that is 800 bytes long, 4 headers. It was a signout page to delete cookies. To expire cookies I was setting them back to my birthday. This did not work in nginx, they must be expired by less than a month to pass validation to remove the cookies.
I ran a check on a few more different, but invalid headers and got the same result. If nginx cannot validate the header it throws: upstream sent too big header while reading response header from upstream
2015: more information from experience:
upstream sent too big header while reading response header from upstream is nginx's generic way of saying "I don't like what I'm seeing"
Your upstream server thread crashed
The upstream server sent an invalid header back
The Notice/Warnings sent back from STDERR broke their buffer and both it and STDOUT were closed
3: Look at the error logs above the message, is it streaming with logged lines preceding the message? PHP message: PHP Notice: Undefined index:
Example snippet from a loop my log file:
2015/11/23 10:30:02 [error] 32451#0: *580927 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined index: Firstname in /srv/www/classes/data_convert.php on line 1090
PHP message: PHP Notice: Undefined index: Lastname in /srv/www/classes/data_convert.php on line 1090
... // 20 lines of same
PHP message: PHP Notice: Undefined index: Firstname in /srv/www/classes/data_convert.php on line 1090
PHP message: PHP Notice: Undefined index: Lastname in /srv/www/classes/data_convert.php on line 1090
PHP message: PHP Notice:
2015/11/23 10:30:02 [error] 32451#0: *580927 FastCGI sent in stderr: "ta_convert.php on line 1090
PHP message: PHP Notice: Undefined index: Firstname
you can see in the 3rd line (from the 20 previous errors) the buffer limit was hit, broke, and the next thread wrote in over it. Nginx then closed the connection and returned 502 to the client.
2: log all the headers sent per request, review them and make sure they conform to standards (nginx does not permit anything older than 24 hours to delete/expire a cookie, sending invalid content length because error messages were buffered before the content counted...)
examples include:
<?php
//expire cookie
setcookie ( 'bookmark', '', strtotime('2012-01-01 00:00:00') );
// nginx will refuse this header response, too far past to accept
....
?>
and this:
<?php
header('Content-type: image/jpg');
?>
<?php //a space was injected into the output above this line
header('Content-length: ' . filesize('image.jpg') );
echo file_get_contents('image.jpg');
// error! the response is now 1-byte longer than header!!
?>
1: verify, or make a script log, to ensure your thread is reaching the correct end point and not exiting before completion.