Daily recurring 502 Bad Gateway

An interesting issue, though somewhat aggravating as this is happening to a live and active website.

=> Every morning around 8am, our website goes down with a 502 Bad Gateway Error. It’s almost on the dot in Google Analytics. There are no major traffic spikes around this time, we have traffic around the clock.

=> The website uses 140-180mb of ‘real’ memory, the rest is cache. What I did notice is that cache slowly creeps up before these times and gets pretty close to the limit set for the VPS. I’ve upped the VPS by 50mb each morning this happened, but the issue keeps returning. It could be this, but I am not 100% sure.

We’re running Nginx with PHP 5.4.20. We’ve got some custom settings in terms of browser caching, etc.

The website itself uses the Wordpress platform and is fully up-to-date. When it runs, I am more than happy with the speed.

Any thoughts, suggestions, comments are highly appreciated.

For those interested, the website can be found here: www.manapool.co.uk
Our old design was DHSOTM in 2010.

I’ve opened a ticket over 2 days ago and am yet to get a response from support. What’s going on guys?

My only solution is to keep increasing ram, which is nice for you guys as you earn more money, but it doesn’t resolve my problem: the site keeps going down whilst it has -plenty- of real memory left.

That’s what they keep telling me too - increase RAM. I monitor my site constantly and I do not see why I have to increase it since it is nowhere near what I have it set at.

Have you received any help that you can share? I am beyond frustrated.

I’m sorry to say I’ve not received any help that resolved this issue whatsoever. The approach to solving it was to rent a server from another host, install the site on that (with the exact same configuration in terms of OS/Nginx/Etc) and see how that did.

End result: The site hasn’t been down even a single second since. It also dropped in ‘server response time’ by an enormous amount and the site feels a lot more responsive.

The really sad thing: Even with the £10 monthly discount Dreamhost had provided me (and don’t get me wrong, I am thankful for that), the other host is still cheaper for a much better kitted server.

If I have to be frank, the VPS experience with Dreamhost was an outright disappointment. I would strongly recommend against it.

I am not super tech but I have been troubleshooting - do you by chance use Cloudflare and W3 Total cache?

That is very interesting. The exact same config. Hmmm.

Apologies for the delay, I only go through my e-mails at a specific time interval every 24 hours as I’m really busy the rest of the time.

You’re correct - we use both W3TC and Cloudflare. Things are running a -lot- better.

That’s all you guys were able to find out? I’m using a caching plugin & Cloudflare, but I cannot even edit an image without the 502 error.

Do you think Dreamhost has a configuration issue when it comes to wordpress?

Have you searched through your error logs to see what is mentioned there?

Sorry, but it’s not the “exact same configuration” since the other host may (and probably does) have their server configured differently.

Slogging through error logs is never fun, but it can often track these things down in a way that other techniques can’t.