Nginx hangs when you use try_files, map, request_uri and long url

Hi,

For some reason, when I use long key with Map Module the whole nginx
seems to hang.

Some background:
I have two backends, say old_app and new_app. both have own named
locations, @new_app and old_app. In order to redirect urls I tried to
use:

map $request_uri $map_apps {
default @new_app;
/asd @old_app;
}
try_files /not_exist $map_apps;

And it was working, then I added another key, 70 chars long, with
commas, - and numbers, like “/foo-bar,123,asd-qwe-asdasdasd”

since the keyword have 70 chars I had to change default 64 value of
map_hash_bucket_size, I changed it to 128.

Now, if I access the ‘/foo-bar,123,asd-qwe-asdasdasd’ url, nginx just
hangs, firefox return ‘connection reset’, wget seems to retry every 3s
with message ‘no data’. I cant access any vhost, I cant even stop nginx,
the workers ignore master, when I nginx -s stop, the workers are still
alive, when I kill master with sigTERM, the workers are still alive,
eventualy, after few minutes they starts working and support requests or
just die.

The underlaying system is debian6, nginx version 1.1.19 (from
squeeze-backports), 64bit.

even if I have only default entry in map, and then access the long url,
the nginx hangs, but when I hash-out the map and try_files lines, I can
access the url and see 404 error.

fwiw I tried to use map since I have about 100 URLs that I want to
proxy_pass to old_app, rest have to be handled by new_app.

– Piotr.

Hello!

On Mon, Jun 18, 2012 at 09:51:31PM +0200, Piotr K. wrote:

map $request_uri $map_apps {

even if I have only default entry in map, and then access the long
url, the nginx hangs, but when I hash-out the map and try_files
lines, I can access the url and see 404 error.

fwiw I tried to use map since I have about 100 URLs that I want to
proxy_pass to old_app, rest have to be handled by new_app.

The problem isn’t map, the problem is try_files which is broken in
1.1.19. Please upgrade to 1.2.0 at least, or apply the following
patch:

http://trac.nginx.org/nginx/changeset/4601/nginx

Changes with nginx 1.2.0:

*) Bugfix: a segmentation fault might occur in a worker process if 

the
“try_files” directive was used; the bug had appeared in 1.1.19.

Maxim D.

Hello.

On 06/18/2012 10:02 PM, Maxim D. wrote:

The problem isn’t map, the problem is try_files which is broken in
1.1.19. Please upgrade to 1.2.0 at least, or apply the following
patch:

Changeset 4601:084137d883ec – nginx

Changes with nginx 1.2.0:

 *) Bugfix: a segmentation fault might occur in a worker process if the
    "try_files" directive was used; the bug had appeared in 1.1.19.

Thank you very much Maxim, the patch works. :wink:

– Piotr.