How to clear the cache of nginx?

Question

I had the exact same problem - I was running my nginx in Virtualbox. I did not have caching turned on. But looks like sendfile was set to on in nginx.conf and that was causing the problem. @kolbyjack mentioned it above in the comments.

When I turned off sendfile - it worked fine.

This is because:

Sendfile is used to ‘copy data between one file descriptor and another‘ and apparently has some real trouble when run in a virtual machine environment, or at least when run through Virtualbox. Turning this config off in nginx causes the static file to be served via a different method and your changes will be reflected immediately and without question

It is related to this bug: https://www.virtualbox.org/ticket/12597

You can also bypass/re-cache on a file by file basis using

proxy_cache_bypass $http_secret_header;

and as a bonus you can return this header to see if you got it from the cache (will return 'HIT') or from the content server (will return 'BYPASS').

add_header X-Cache-Status $upstream_cache_status;

to expire/refresh the cached file, use curl or any rest client to make a request to the cached page.

curl http://abcdomain.com/mypage.html -s -I -H "secret-header:true"

this will return a fresh copy of the item and it will also replace what's in cache.

Unless you configured a cache zone via proxy_cache_path and then used it (for example in a location block), via: proxy_cache nothing will get cached.

If you did, however, then according to the author of nginx, simply removing all files from the cache directory is enough.

Simplest way: find /path/to/your/cache -type f -delete

You can delete cache directory of nginx or You can search specific file:

grep -lr 'http://mydomain.pl/css/myedited.css' /var/nginx/cache/*

And delete only one file to nginx refresh them.

I run a very simple bash script which takes all of 10 seconds to do the job and sends me a mail when done.

#!/bin/bash
sudo service nginx stop
sudo rm -rf /var/cache/nginx/*
sudo service nginx start | mail -s "Nginx Purged" [email protected]
exit 0

There's two answers in this question.

• One for nginx as reverse cache
• Another for cleaning the browser cache by header input (this one)

Use:

expires modified +90d;

E.G.:

location ~* ^.+\.(css|js|jpg|gif|png|txt|ico|swf|xml)$ {
    access_log off;
    root /path/to/htdocs;
    expires modified +90d;
}

I had this problem also.

• Could not find any nginx/cache folder
• sendfile was off

My domain uses cloudflare.com for DNS (great service!). Aha! There it was:

cloudflare.com -> caching -> Purge Cache (I purged everything) That solved my problem!