Sudden 521 for subdomain

matthias1 · February 17, 2020, 3:57pm

Dear Community,

i’m running my website mydomain(dot)com on Cloudflare with the Setting SSL Full.
I’m also using a service called cloudapp that I have set with a custom url share.mydomain(dot)com that worked always fine.

For one day now however the share.mydomain(dot)com throws a 521 error

My cloudflare setting for this is a CNAME record with share that points to custom.getcloudapp(dot)com as suggested and always worked. I also deleted this record, proxied it, tried SSL flexible, deleted the cloudflare cache, etc.

Nothing so far worked! the normal website mydomain(dot)com works just fine with ssl and everything. The share.mydomain(dot)com

I have a folder /share on my server that I can call with mydomain.com/share. I have an .htaccess script running to have the share.mydomain(dot)com also point to this directory and this always worked.

Any ideas?

sdayman · February 17, 2020, 2:00pm

If you set it to in DNS, does it work?

matthias1 · February 17, 2020, 2:11pm

This is what I have right now …

If I set it to DNS Only (and not proxied) … This site can’t be reached (ERR_CONNECTION_REFUSED)

But … this happens now with proxied and normal.

sdayman · February 17, 2020, 2:18pm

Well…that certainly explains the 521. Your server isn’t working.

matthias1 · February 17, 2020, 2:27pm

Ok, how so, from today on? As the mydomain(dot)com is normally up and running. Also mydomain(dot)com/share is working normally.

# CLOUDAPP SSL Verification sslforfree
RewriteEngine on
RewriteCond %{HTTP_HOST} ^share\.mydomain\.com$
RewriteCond %{REQUEST_URI} !^/share
RewriteRule ^(.*)$ /share/$1 [L] 
# CLOUDAPP SSL Verification sslforfree

This is what I have in the very first lines of my .htaccess and always had it like that.

What could that mean “the server is not working” for the subdomain, the server is up and running, I can call all urls on the server, just the subdomain is “down”? But the subdomain is a simple subdirectory on the running server right now.

I basically only created this to have an SSL cert installed inside this share directory for Cloudapp links (that I use daily) to also be https.

sdayman · February 17, 2020, 2:56pm

If you set that hostname to and it doesn’t work, then there’s something wrong with your server configuration. https://stackoverflow.com/ is a good place to go for help with server configuration problems.

matthias1 · February 17, 2020, 2:53pm

Ok, thanks @sdayman. This is super weird though, that it always worked and from today on suddenly stopped working. I’m running this server on an AWS EC2 instance right now.

sandro · February 17, 2020, 2:56pm

And you probably stopped that instance. Nothing running at the given hostname, it isnt even pingable -> sitemeer.com/#custom.getcloudapp.com

As @sdayman said, the server isnt working. You need to get it to work, then make sure HTTPS works, and only then proxy it again.

matthias1 · February 17, 2020, 2:59pm

Ah, ok, cloudapps service is down. just got it. Thank you.

system · March 18, 2020, 2:59pm

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