What does this nginx error "rewrite or internal redirection cycle" mean?

Solution 1:

It's a strange one all right, though I'm going to bet the problem is with:

        try_files $uri $uri/ /index.html;

The problem here is that the second parameter here, $uri/, causes each of the files in your index directive to be tried in turn. If none are found, it then moves on to /index.html, which causes the same location block to be re-entered, and since it still doesn't exist, you get an endless loop.

I would rewrite this as:

        try_files $uri $uri/ =404;

to return a 404 error if none of the index files you specified in the index directive exist.

---

BTW, those requests you are seeing are Internet background noise. In particular, they are probes to determine whether your web server is an open proxy and can be abused to hide a malicious user's origin when he goes to perform malicious activity. Your server isn't an open proxy in this configuration, so you don't really need to worry about it.

Solution 2:

You will also get this error message if your index.php is entirely missing.

---

Solution 3:

This was annoying. It was working a few weeks ago, and it failed on me when I tried today.

I believed an upgrade of Ubuntu nginx package cause the default directory of where Ubuntu kept the standard index files changed, so the line:

root /usr/share/nginx/www;

Won't work anymore as the location of the files are at /usr/share/nginx/html.

To fix, one can just change the root pointer to the correct directory, or create a symlink to the new directory:

cd /usr/share/nginx
sudo ln -s html www

Works for me.

---

Solution 4:

I ran into this problem yesterday because I was testing nginx over a proxy server that had cached a redirect that no longer existed. The solution for me was to $ sudo service squid3 restart on the squid3 proxy server I was connecting through.

---

Solution 5:

Had this error today, spend a few hours figuring the cause. Turned out someone deleted all the site's files.