Error 503 Site Temporarily Unavailable

[MacSeah]

Dear Xenforo Community,

I am experiencing a problem that I am unsure of how to proceed. My forum is hosted on Dreamhost's Dedicated servers, and I have Xenforo installed in the sub folder of /f/ of my main domain. Yesterday, I installed Cloudflare to get HTTPS:// SSL certification. The DNS for my site was changed in Dreamhost and left to propagate. This morning, I realized that my entire site was down with a 503 Error - Site Temporarily Unavailable. I tried to revert the DNS in Dreamhost to the default and restart the server, but nothing is changing.

When trying to load HTTPS:// domain, it shows as Error 503, and without the HTTPs now, the entire forum lags out badly. When using Chrome, I pressed the F12 button, and am seeing the following errors:

Failed to load resource: the server responded with a status of 503 (Service Temporarily Unavailable)
css.php Failed to load resource: the server responded with a status of 503 (Service Temporarily Unavailable)
css.php Failed to load resource: the server responded with a status of 503 (Service Temporarily Unavailable)

Has anyone faced a similar problem with a Xenforo installation on a sub folder, and is there any idea on how I should revert to a working platform?

I would really appreciate any insight on this matter. Thank you.

 

[Mike]

Looking at the site from your customer area, it looks like something with your general PHP setup is very broken. It's unlikely to be CloudFlare related.

Even just accessing rgba.php took 17 seconds. This is a completely standalone script. It does not include any files, it does not touch the database or anything external. It's about 30 lines and does a few very simple things. This should really be running in milliseconds. Unfortunately, this is really something a sysadmin would need to investigate. It's probably an issue relating to how PHP is being invoked (or some sort of network call happening outside of PHP).

 

[MacSeah]

1 week ago, I installed a simple HTML page that doesn't makes any calls to database, since xenforo is installed in /f subdirectory. It did have some weird things like smileys went missing but no biggie other than that. Until I got it on cloudflare and within two hours It was down. At first i suspect it was SSL error but later after approaching my host they claimed that there is nothing wrong on their end and they also mentioned we have a large hit on our database MYSQL. We did not change any other files within this period and couldnt figure out what went wrong.

The site continue to lag or down. I am at loss end with no technical background and I just put it back to cloudflare (SSL off) The site now loads but lag badly. Is there anyway to fix it?

 

[WSWD]

What is your server load? What processes are running? How about disk I/O? It's really impossible to tell why it might be lagging without a lot more information. You say you're on a dedicated server?

 

[MacSeah]

What is your server load? What processes are running? How about disk I/O? It's really impossible to tell why it might be lagging without a lot more information. You say you're on a dedicated server?

I cannot provide you with that since I am not tech savvy at all. I have migrated the site to a new server Aws from dreamhost 16 gb ram dedicated server. For awhile it seems the issue is solved. Now it gives intermittent down time which lasted 15 to 20 mins every few hours. I disabled most of the add-on but doesn't seems to fix the issue.

My server admin told me during those downtime there were absurd increase in database causing the server to overload hence the following error

"An unexpected error occurred."

He has already went one round of optimizing database but still unable to solve the problem. I figured it takes someone familiar with xenforo to efficiently give us a direction for this situation.

I googled and found out that some of them had this problem but I see no resolution to it. Deeply appreciate if any xenforo members can help.

Willing to pay for your time to get rid of this problem.

Can anyone kindly point me to the right direction?

 

[MacSeah]

Looking at the site from your customer area, it looks like something with your general PHP setup is very broken. It's unlikely to be CloudFlare related.

Even just accessing rgba.php took 17 seconds. This is a completely standalone script. It does not include any files, it does not touch the database or anything external. It's about 30 lines and does a few very simple things. This should really be running in milliseconds. Unfortunately, this is really something a sysadmin would need to investigate. It's probably an issue relating to how PHP is being invoked (or some sort of network call happening outside of PHP).

I had a admin to look into that, the site now is up back after the new configuration but still suffers intermittent down error. Overloading database. I would appreciate if you can point me to the probable causes of this.

 

[Paul B]

It's going to be server related.

Your host or sysadmin would be best placed to investigate and resolve that.

 

[MacSeah]

It's going to be server related.

Your host or sysadmin would be best placed to investigate and resolve that.

Any chance that it is because of a rogue plugin, else some database corruption during my migration. To a new server?

We are trying to eliminate and pin point the issue. Any opinions are welcome, once this is solved I will put up how we did it.

brogan Thank you for taking time to reply.

 

[TPerry]

You need to have the sysadmin check the server load during those times and also the number of active HTTP connections - especially multiple connections from the same IP(s).

 

[MacSeah]

You need to have the sysadmin check the server load during those times and also the number of active HTTP connections - especially multiple connections from the same IP(s).

You are suspecting a blast of connection which can be interpreted as a possible DDOS attacked?

Will do just that and sees if that is what happened.

Will update in this thread.

 

[TPerry]

You are suspecting a blast of connection which can be interpreted as a possible DDOS attacked?

Will do just that and sees if that is what happened.

Will update in this thread.

Exactly... I've seen similar happen when some people have been subjected to heavy traffic from either DDOS style attacks or similar.