General slowness, shared server

**kb0kqa** · 08-30-2010, 09:01 PM

One of the sites I maintain, on web3 and using mysql2, has been experiencing erratic slowness problems for a while now.

The site is a Drupal site and phpbb2 - nothing too out of the ordinary at all. http://mngca.org

I've been trying to put my finger on some of the problems recently and am having a hard time determining where the problem is and would love some insight if anyone can offer some. Normally when I see the problems the load averages on the server are low (generally less than 3, usually around 1). I've looked at the processlist on the sql server to see if we had any stuck processes (show processlist

and don't see anything out of the ordinary (this did catch us one time about a month ago with a stock Drupal query that would get stuck).

Often I write up the problems to poor internet connectivity on my part, but last week I had a number of 408 errors being generated when trying to do page loads as well.

The problem seems worse (to me anyway) when I know I'm doing a write to the database (such as creating/editing a node), although I also understand that for Drupal in particular that there are writes being done to the database for every page load.

Drupal keeps track of the "page generation time" - I have many pages that have a generation time well over 5 seconds, on up to over 30 seconds. Some of the pages that make that list are simple text nodes, some of just a paragraph of text - no other code being executed, etc. When I load the pages I've seen mixed results - sometimes it takes forever to load (I had a 408 error loading one of them), others load nearly instantly (which I guess is the norm for picking pages on the list).

I've seen similar problems with phpbb (which is entirely a stock load of the most recent phpbb2) - page loads take a long time, searches take a long time. The problem is real hit and miss though and never reproducible. It does seem to affect all pages in short time windows, rather than one page doing it consistently.

Anyway, any suggestions on what to look for or how to nail down the problems?

**host** · 09-01-2010, 11:59 PM

I saw your post while I was reading the homepage of steadfast to check if there is a maintenance. My sites have started to give 408 to googlebot like your sites.
mysql2 has been slow for my sites since the last 1 year. However at this time may be there is also a network problem in addition to the speed problem of mysql2. Because 408 errors are new to my sites.

**Kevin** · 09-02-2010, 01:36 PM

We have not seen any ticket reports about 408 errors at this time, but they are caused by application timeouts, usually due to slow PHP scripts (web server load) or slow MySQL response (MySQL server load). The best thing you can do to help us diagnose this problem is to send in a ticket right away when you see performance problems so we can try to identify any problem user accounts that may be abusing resources and tune the system or get in touch with those users to repair the load problems.

**kb0kqa** · 09-10-2010, 09:08 PM

Originally Posted by Kevin

We have not seen any ticket reports about 408 errors at this time, but they are caused by application timeouts, usually due to slow PHP scripts (web server load) or slow MySQL response (MySQL server load). The best thing you can do to help us diagnose this problem is to send in a ticket right away when you see performance problems so we can try to identify any problem user accounts that may be abusing resources and tune the system or get in touch with those users to repair the load problems.

The last ticket I had open on 408 errors was in July (#WZY-108534), at which time I was initially threatened to have my account suspended if I didn't bring my queries under control (yet the query in question was a stock Drupal query that shouldn't have hung in the first place - once it was killed then the remainer of the queries ran immediately), yet at the same time I had to ask for further help in identifying the problem. Since then I've naturally been a little more hesitant to stick my neck out further with your tech support people. I'm not saying that the problem wasn't one related to our site (although it was a simple Drupal query), but the response we received caused one of our board members (an Oracle DBA) to ask me to search for another host (which I'm relucant to do and haven't done yet as overall I've been happy with Steadfast despite the rare problem or two). The initial response we received (which I'm guessing you're going to look up) was extremely accusatory with no actual help for me to diagnose, stop, or repair any problem that may have been related to our site (although I did eventually get the information through a dialogue).

I agree with 'host' - this really appears to be related to mysql2 (which we're also on). I have a separate php page that solely displays the load average of the server we're on (web3) and it's rarely, if ever, above 2 or 3.

Once I asked the question on a private forum that 7 people had access to on our phpbb forum I had 5 of them respond that they see regular slowness in the site. Until I asked them they all thought it was just them seeing the problem and related to their connection to the internet (which is what I had thought for quite some time until I actually got the 408 errors, at which time I started paying more attention).

The problem seems very sporatic - I see it for 10 or 20 seconds, then it's gone. Maybe I'll see it again if I stick around long enough, but chances are I won't. I'd have to estimate that I see it once every 3 or 4 times that I browse our forums (for say a 5 minute session total), so the problem isn't what I would call 'rare', just sporatic.

At this point I'd be interested in getting off mysql2. We originally got on it when it was pretty new and under no load, but I feel pretty convinced that our problems are related to the database. I assume I can open a ticket to switch databases back to the original?

**miko3ed** · 10-01-2010, 10:54 AM

I'm experiencing the same thing, and it mainly seems to be affecting site transactions to mysql2... Browsing pages that don't interact with the database appear unaffected, and when I take my drupal sites offline the offline page, which doesn't hit the DB, comes up instantly...

If there is any way I could jump off mysql2 and try a different db server I would in a heartbeat...