Random 503 Error Message

[Ollie]

My website keeps throwing 503 permission errors randomly while going around my website. It is also loading very slowly. When I contacted my hosting provider, they saw that my website had gotten marked in mod_security; they white listed what was causing it but now it seems to be happening again. Any help would be appreciated.  I am using Abantecart 1.2.0 with some custom plugins and am running php version 5.4 with fast cgi.

[llegrand]

Ollie,  in my experience random 503s are indeed a server issue. Most of the time, a 503 error occurs because the server is too busy or because there's maintenance being performed on it.  so I suggest getting with your provider again.   

Also if you are running cPanel and most of us are,  I have experienced some interesting changes over the past 10 days with some of my sites (no 503s)  due to cPanel changes - here's the link to the changelog for cPanel -  as you can see there's quite a few.  And again these will be server side issues that your provider needs to assist in getting things in order.

https://documentation.cpanel.net/display/ALD/11.52+Change+Log

Lee

[Ollie]

Ollie,  in my experience random 503s are indeed a server issue. Most of the time, a 503 error occurs because the server is too busy or because there's maintenance being performed on it.  so I suggest getting with your provider again.   
https://documentation.cpanel.net/display/ALD/11.52+Change+Log

Hi Lee, thank you for your suggestion. I did check with Bluehost and they said the reason I'm having issues connecting to my database is due to my slow MySQL queries. They said that, "Every MySQL query opens a connection through the MySQL user. Normal times for MySQL queries are under 1 second." According to MySQL log, several queries took longer than 2 seconds, one or two took 5-7 seconds, and one took over 9 seconds! They said that MySQL user is allowed 15 connections at a time. According to Bluehost, this is enough, considering that those connections are only held open for less than a second. However, it becomes a problem "because the connection is not closed until the query is finished", causing all of my connections to be used up. When that occurs, I get an error stating it can't connect to my database. This means that it is making my site load slow, and giving me a 503 error. They further suggested that I optimize the problem queries. I looked at the log, but I have no idea how to read it. It sounds Greek to me. If I email you a copy, can you take a look and explain to me how to interpret the data? Besides optimizing these queries, I'm also planning on repairing and optimizing the database. Have you ever done that? Any insights on that would be greatly appreciated.

Oliver

[llegrand]

the Admins need to respond to the held up part -  You're still running 1.2.0 and there was some issues with the upgrade from 1.1.9 to 1.2.0  if I recall correctly.

As to running the optimaization and the repain on DB  -  it is easy to do -  and is done within my PhpAdmin.  Here's the link from BlueHost about it.

https://my.bluehost.com/cgi/help/496

Yes  I do run those on my DBs particularly ones that are heavily used. 
DO NOT overlook the instruction to backup up your DB PRIOR to running  (just in case!)
But this would be a good start -  as I think your sites get a lot of work out.

Lee

[Ollie]

You're still running 1.2.0 and there was some issues with the upgrade from 1.1.9 to 1.2.0  if I recall correctly.

Were these issues corrected in later versions? If so, I might go in the direction of upgrading to the latest version. My concern is whether the extensions I added to version 1.2.0 would still work with 1.2.4. I also want to keep using the default5_html template. Not sure how (and if) it would work with v. 1.2.4.