CPU and Memory Usage Spike Caused by 3.5.2
 

I left a comment under the theme release about this but as it's not appeared I can only assume it's not been received. So here goes again:

I installed 3.5.2 today and my blog's CPU usage jumped above 37% and its memory usage above 5% (I think it hit 11% at one point). I tried the theme on a few more servers and they all showed massive CPU and memory usage. Everything returned to normal once I reverted to version 3.5.1. My question is, has this issue been fixed in version 3.5.3?

Call me fussy but I don't want to be responsible for my clients having their server accounts suspended. Until I know the bug has been fixed I will advise my clients to stick with version 3.5.1; which is a shame because Atahualpa is a great alternative to Suffusion - one has square looks, the other has rounded looks.

How are you measuring memory usage?

All sites I tested it on used servers provided by Hostgator. Their HG theme provides a refreshable CPU and Memory usage meter. I used that meter, with several refreshes, to check CPU and memory usage. Plus I looked at the running processors. On each occasion the process with the highest usage was index.php (WordPress). That process was not a lone runner - for some reason the theme prevented plugins from quitting or the high CPU usage prevented them from quitting. I can't recall which plugins it interfered with but I believe they were different ones at different times.

The only reason I noticed the problem is that one of the tested sites had its CPU usage so high that it was unable to load (Received the Apache server error that's usually accompanies the suspension of WordPress's index.php).

There was a bug in 3.5.2 that caused problems with earlier versions of WP and I only had it installed on one site for a couple of days with no issues. I would be curious to hear if 3.5.3 does the same thing your 3.5.2 installs on your Hostgator sites.

All sites were WP 3 MS. I'll try 3.5.3 later today and post the result here.

please install the WP-Memory-Usage plugin and look at the usage in the dashboard with both versions

I installed the memory usage plugin on a site running 3.5.3 and WP 3.0 and got this:

• PHP Version : 5.2.13 / 32Bit OS
• Memory limit : 64 MByte
• Memory usage : 25.08 MByte

And a bar showing 39%.

I don't know how to interpret this, however. And there isn't any information on the developer's site about how to read the results.

Paula can you switch to 3.5.1 and see if there is a change?

Juggledad, I can't risk taking the time to activate the 3.5.3 version and checking the memory usage plugin. If any of my sites get suspended then fair enough, I can explain the circumstances and have them unsuspended within a few hours but if one of my client's sites is suspended then I risk a lot more than a few blog readers. Looking at Paulae's reply it seems the problem still exists.

I've checked the error log for the site on my server that I activated the theme and it shows nothing pertaining to the theme.

Ignore this bit below here. It was the first part of this comment - read my next comment to see why:

Paulae, if you're on a shared server be aware that you account could be suspended for overuse of memory usage.

With Hostgator, if either memory or CPU usage is consistently above 25% for longer than 90 seconds at a time they suspend (forcefully stop) any offending script. With WordPress this invariably means index.php is suspended; and without that your site will not be browsable.

I just disabled almost all plugins and activated the 2010 theme with these results.

• Memory limit : 64 MByte
• Memory usage : 25.08 MByte

I took the plunge and tested 3.5.3.

Here re the results...

Pre activation of 3.5.3:

Hostgator provided resource usage monitors:

CPU: 0.3%
Memory: 0.1%

WP-Mem provided resource usage monitors:

Memory limit: 64 MByte
Memory usage: 27.92 MByte
Bar Reading: 44%

Post activation of 3.5.3:

Hostgator provided resource usage monitors:

CPU: 0.3%
Memory: 0.1%

WP-Mem provided resource usage monitors:

Memory limit: 64 MByte
Memory usage: 27.97 MByte
Bar Reading: 44%

It looks like the bug's been fixed in version 3.5.3.

Paulae, I was mistaken. I apologize for frightening you :)

there is very little diffenence from 3.5.1 to 3.5.3, mainly the patches were applied and an if statement surrounding the new menu stuff so pre WP 3 could run it.

JD, I tried it on another site (can't risk a problem right now with the Gazette):

aghca.org

With 3.5.1:

usage: 21.43 mbyte
bar: 33%

With 3.5.3:

usage; 21.46
bar: 34%

This site it hosted at hostgator.com as is the Gazette.

That amount of change doesn't seem to me to indicate a big jump in memory and CPU utilization.

I think the problem must just be a quirk within 3.5.2.

The big memory/CPU issue might be when the number of concurrent users goes up. There are some blog reports on performance that make interesting reading at http://loadimpact.com/blog/load-testing-wordpress

Hi Juggledad, I'm not sure that that's the reason. The site I tested 3.5.2 with on my own server receives only a hundred or so visitors per day (the whole multi site receives about the same - it's a new domain), one of the other sites on a different server receives about 1,800 visitors per day (multi site wide, >4,000 <5,000 - old domain). It must have been an unintended consequence of a fix to 3.5.2 that removed the fault from 3.5.3.

Thank for pointing out that link, it'll make interesting reading.