DreamPress problem with images & 503 errors

We’ve been using DreamPress at http://www.radiosurvivor.com almost since the service started, and we continue to have persistent problems with images not loading intermittently. These are all images uploaded and resized using the WordPress interface, and there’s no one image that refuses to load all the time. It’s unpredictable.

We have contacted DreamHost support numerous times, and most recently they say they can’t recreate the problem, even though it persists.

To troubleshoot we’ve turned off all unnecessary plug-ins, and double-checked them against those that don’t play nice with Varnish, just to be sure. That made the problem less worse, but it has not gone away.

As well, we still experience 503 Varnish cache server errors regularly when posting, not matter how often we flush the cache manually.

We’re getting to the end of our patience, particularly with the image problem. I understand that it’s intermittent, and therefore not very easy to recreate. Yet, I experience it at least 40% of the time – something that has been corroborated by other users across different browsers and OSes.

Any help would be appreciated, since it’s making us reconsider choosing DreamPress.

I have a suspect and it’s your theme.

You’re running a theme that uses TimThumb. TimThumb does dynamic image resizes and caches them. If that gets hung up for any reason, I can see it causing a random 503, and especially only on images :frowning:

Thanks for the reply. I wish it were that simple. I’ve specifically chosen WordPress’s image resizing engine (WP Post Thumbnail) and disabled Tim Thumb in the theme.

Also, we only installed the Woo Canvas theme a few weeks ago, and we were having the same problem before then using a mostly-stock child theme of Twenty-Ten/Eleven.

http://wordpress.org/plugins/wp-post-thumbnail/ ? That’s not WP’s engine, and it’s out of date so it’s not even using the new hooks. It’s also throwing a lot of errors on the back end so I wouldn’t use it at all, personally. WP resizes images on it’s own when you upload them and you can edit them (and JUST edit thumbnails) from the media panel.

I looked at your server logs and I think ModSecurity is clashing with something.

[Mon Feb 03 01:11:41 2014] [error] [client SOMEONESIP] client denied by server configuration: /home/wp_46cvmx/radiosurvivor.com/wp-content/uploads/2011/07/shelterchildrenlondon1940.jpg

I’ve turned it off on your server for a test, but since I can’t reproduce this one either you’ll have to let me know how it goes. FWIW, we don’t like doing this, as it prevents us from being able to protect you from certain brute force attacks on your box.