[RCD] Revisiting ancient issue - Apache2 100% CPU when competing for UW-IMAP

till till at php.net
Tue Sep 28 13:57:08 CEST 2010

On Tue, Sep 28, 2010 at 1:45 PM, Rimas Kudelis <rq at akl.lt> wrote:
>  2010.09.17 11:29, A.L.E.C rašė:
>> On 17.09.2010 10:22, Rimas Kudelis wrote:
>>>   For a record: I am using courier-imap, and I too have this problem from
>>> time to time (e.g. now). So it's definately not UW's fault. I think when
>>> I googled for it, it appeared to be a bug in PHP, isn't it?
>> Probably it's PHP's fault and maybe relied on specific PHP+Apache
>> configuration.
> I'm having this problem again, for about three hours now. Is there
> anything I could look for in my logs or any other means of debugging
> that would help?

Yes there is! :D

So to figure out what happens when RoundCube is used, I suggest you
install xdebug and temporarily enable profiling of all requests.
Beware though - the cachegrind files are huge and tend to eat
diskspace quicker than you think. So make sure to watch the directory
they are saved to.

In a nutshell!

sudo pecl install xdebug
[depending on your PHP install, you may or may not have to manually
insert the following into php.ini: extension=xdebug.so]

Then, use the following directives in php.ini:

Depending on your setup, you will need to restart PHP/Apache.

To analyze the files:

This will allow you to troubleshoot where most time is spend and I
guess this will either allow us to fix a bug (or more), or allow you
to troubleshoot your setup and improve it.

If no one finds any errors in my writeup, I'd also add this to the wiki.

List info: http://lists.roundcube.net/dev/

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