View Full Version : CPU throttling
01-02-2011, 01:20 AM
I'm sorry if the topic is not related.
What is CPU throttling?
Recently I've seen some warning message in my control panel:
* During the past 24 hours your account has been throttled for a total of 7120.177 seconds.
What does this signify?
01-02-2011, 01:53 AM
CPU throttling is originally the technique to 'slow down' the CPU to protect it from overheating and consequent damage. But in the hosting circles, it is a process to throttle your share of the CPU slices for excessive usage of server resources. It basically indicates that your host is resorting to throttling your CPU usage for some reason - usually excessive usage. It will make your site slow down at that time or in some cases even make your site inaccessible.
In your case, in a 24 hour period, your site was slowed down or 'frozen' for nearly 2 hours. Clearly it calls for some serious action. Find out what process caused this.
01-02-2011, 08:54 AM
If you are running a VPS the system automagically limits your CPU usage to the max that you are allotted based on the level of account that you pay for.. The warning message is to let you know that you are maxed out on your account and that you should consider increasing your account limits to bring you site back to full speed or fix the service that is eating all your CPU cycles..
Looks like time to upgrade..
01-03-2011, 07:46 PM
On shared hosting accounts CPU throttling is common and not usually an issue, or as my host states "Throttling for less than 600 seconds in any given hour will not usually negatively affect your site's performance for visitors."
CPU Cycles are throttled on shared servers so you do not create a performance hit on the other accounts on that server who are paying the same as you for service.
If your server is being throttled a lot, and NOT due to excessive traffic, you might consider this list of possible resource hogs in your site's design (compliments of my hosting plan):
* Poorly coded Php scripts such as multiple nested loops, or infinite loops.
* Themes, Addons, or Plugins (if you just added a new component to your script, you may want to remove it to see if that new component caused your site to suddenly perform slowly)
* Queries that return inordinately large dataset results (eg: 100,000 records) in the Response object of a round trip to the server.
* Queries that take too long to execute due to heavy aggregation commands like SUM, COUNT over very large datasets without proper indexing.
* Queries that are doing complex unoptimized nested Joins.
* Queries that execute large batch commands like INSERTS, UPDATES, OR DELETES - these types of sql calls are 10 times more expensive and resource intensive than the SELECT query command.
* DDoS Attacks
* Any process that uses too much RAM, like a rogue cron job
* Too many simultaneous connections like Downloads, FTP, IMAP, or PHP
Otherwise, you might look deeper in to the Knowledge Base of your hosting provider as they might provide you with tools or guidelines to specifically isolate what the problem is in your instance.
01-03-2011, 10:45 PM
CPU Cycles are throttled on shared servers so you do not create a performance hit on the other accounts on that server who are paying the same as you for service........
This is what is means. Any network would do this if one IP is hording the resources.
01-07-2011, 05:46 AM
Should I talk to the customer care person and find out the probable reason or just switch to any other virtual private server (VPS) hosting?
02-02-2011, 08:18 PM
I think anytime you are starting to receive a decent amount of traffic, it may be time to upgrade to a VPS hosting acct. I suspect some CPU throttling on one of my sites. Shared web hosting is a great place to start, but I am seeing the beauty of VPS and Dedicated and Cloud hosting recently
04-22-2011, 05:45 AM
Due to the recent changes in Google algorithm, there was a drastic decrease in the traffic.
Now the CPU throttling has decreased.
Anyway, I think I should get into some good VPS.
Any recommendations please......
06-04-2011, 06:33 AM
Hi, I have a DFI Infinity II motherboard, and there is an option under advanced chipset features that reads "CPU-Thermal-Throttling" It has values that I adjust by the percentage, such as 37.5%, 50.0%, etc. What exactly does that do? Thanks
06-04-2011, 06:53 AM
It slows the CPU down so it doesn't overheat
09-22-2011, 12:20 PM
Even in the period of less traffic, I'm seeing the message:
During the past 24 hours your account has been throttled for a total of 17063.094 seconds.
The customer support person says - "It completely depends on the programming of your script. The throttling is not because of traffic per se, it's because of CPU usage."
What should I do now?
09-23-2011, 04:10 PM
After installing the GZIP addon into Apache, I noticed that our CPU usage dropped dramatically. The number of httpd connections decreased since most people's browsers are able to download gzipped versions of the web pages much faster than the full versions. I'd login and type in "top" and see the CPU usage high. After installing the gzip mode and restarting Apache, our pages loaded much faster and it took a huge load off the CPU. I don't know why all web servers do not do this by default. Watch this video from Google webmasters that will try to explain it in easy to understand terms. Go on YouTube and search for this: Mjab_aZsdxw
I copied the code from here and put it at the bottom of my httpd.conf file. (Very important: make sure you back up of this file first in case you have to revert back!)
I originally posted the link, but the forum says I don't have enough posts to give you guys the link.
# Insert filter
# Netscape 4.x has some problems...
BrowserMatch ^Mozilla/4 gzip-only-text/html
# Netscape 4.06-4.08 have some more problems
BrowserMatch ^Mozilla/4\.0 no-gzip
# MSIE masquerades as Netscape, but it is fine
# BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
# NOTE: Due to a bug in mod_setenvif up to Apache 2.0.48
# the above regex won't work. You can use the following
# workaround to get the desired effect:
BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html
# Don't compress images
SetEnvIfNoCase Request_URI \
\.(?:gif|jpe?g|png)$ no-gzip dont-vary
# Make sure proxies don't deliver the wrong content
Header append Vary User-Agent env=!dont-vary