Connection closes with a large file list on Nginx 1.5.3 and later

[mihailbulychev]

We use mod_zip module. After setting up a new server (under FreeBSD) we've installed fresh nginx (1.10.1) and found that there's a limit for a number of rules. Also there's a limit on a total rules size. If the limit is exceeded, connection closes and nginx reports an error:

2016/06/08 17:41:33 [error] 82841#101370: *1646064 upstream prematurely closed connection while reading upstream, client: 10.118.254.242, server: , request: "GET /test.php HTTP/1.1", upstream: "http://176.xx.xx.xx:8092/test.php", host: "xxxxx.com".

Two examples:

1. 78 zipping rules, ~11000 byte
2. 99 rules (with a shorter path), ~8000 bytes

If we add one more rule in any of these cases, connection closes with an error.

Could you give us a hint of a possible reason of this behaviour? What nginx settings may affect and fix it? Or it's an nginx's bug?

Everything worked fine with nginx 1.4.4.

mod_zip version is 1.1.6
Nginx config are the same for both versions.

...
server {
listen 176.xx.xx.xx:80;
...
location ~ /upltest/(.*) {
root /usr/home/test;
index index.html;
}
...
}
...

Rule example:

• 6523091 /upltest/A/ABCvJOqZdlmF/ABCo_o_1ak7ouul5gcob0i1jk1qvtko8rm DSC_1234.JPG

nginx's log

[mihailbulychev]

New server and the old problem. Now on the Ubuntu operating system.
Empirically determined that mod_zip module doesn't function properly since Nginx 1.5.3. I've tried variety of settings in nginx and php, but without success. Please, take a look on nginx 1.5.3 changelist, probably it could give any ideas of possible reasons of the problem.

[evanmiller]

For reference:

Changes with nginx 1.5.3                                         30 Jul 2013

    *) Change in internal API: now u->length defaults to -1 if working with
       backends in unbuffered mode.

    *) Change: now after receiving an incomplete response from a backend
       server nginx tries to send an available part of the response to a
       client, and then closes client connection.

    *) Bugfix: a segmentation fault might occur in a worker process if the
       ngx_http_spdy_module was used with the "client_body_in_file_only"
       directive.

    *) Bugfix: the "so_keepalive" parameter of the "listen" directive might
       be handled incorrectly on DragonFlyBSD.
       Thanks to Sepherosa Ziehau.

    *) Bugfix: in the ngx_http_xslt_filter_module.

    *) Bugfix: in the ngx_http_sub_filter_module.

[mihailbulychev]

The error was in our code and we forgot to close this issue. Someone for some reason sent header Content-Length. And this worked fine until nginx 1.5.3.