On Sun, Jan 18, 2009 at 2:00 PM, Alex Davies <alex@xxxxxxxx> wrote: > Hi Eric, Richard, > > Thank-you for your suggestions. I had already tried xdebug - the problem > that I had is that because of the CPU overload it was showing pretty much > everything as screwed! However by using absolute CPU time measures I > managed > to work out what method was involved, and on removing it the situation is > completely resolved. > > I still wonder if there is a neater way to do this! > > Cheers, > > Alex > > On Sun, Jan 18, 2009 at 2:43 PM, Eric Butera <eric.butera@xxxxxxxxx> > wrote: > > > On Sun, Jan 18, 2009 at 3:16 AM, Alex Davies <alex@xxxxxxxx> wrote: > > > Hi, > > > > > > I use a (externally developed) library within my application which > > > used to work fine. However, after a recent update (which unfortunately > > > we can't roll back due to dependencies) I have crazy CPU loads - there > > > are ~20 cores in total on the webservers and they have gone from an > > > average utilization of ~5% to >99%. I am using lighttpd, and so I can > > > see the php-cgi processes using 99% all my CPU! > > > > > > I have an extremely basic understanding of how to track this down, and > > > using XDebug and KCacheGrind I think that I have a pretty good idea > > > which area the problem lies in, but the "problem" is that because > > > whatever it is that has broken is using up the whole CPU everything > > > else slows down. Furthermore, it would appear that a large part of > > > what gets scheduled is luck because sometimes things are instant and > > > the same activity a short while later can take forever. However, based > > > on absolute CPU time's from this XDebug/KCacheGrind analysis and a gut > > > hunch based upon what has changed recently I think I know roughly what > > > it is. I do have a diff of the recent code change, and I have looked > > > at it to no avail. > > > > > > My questions are: > > > - Is there a better way to see what is using up the CPU? There must be > > > a single loop or something talking to an external service, that is > > > using so much CPU user time. Is there a super-quick way to do to this? > > > I really need to know what function (or even line) is using all that > > > CPU time, because I can't spot it in the code. Perhaps this > > > information can be obtained from XDebug but I can't find it! > > > - If there is no such magic answer to this question, what is the > > > correct way to find such a phantom problem? Are there any other > > > applications that might be better? > > > > > > If anyone has any personal recommendations for Consultants able to > > > look at and fix this sort of problem that would be much appreciated > > > too; I am now well out of my depth and sinking fast! > > > > > > Many thanks for any help, > > > > > > Alex > > > > > > -- > > > PHP General Mailing List (http://www.php.net/) > > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > > > > > XDebug can produce a result showing time spent in each function across > > an entire run. So if you were somehow able to turn on xdebug and > > reproduce this issue, it would indeed say what function/method this > > was happening in. > > > > http://xdebug.org/docs/profiler > > > > Sounds like that'd be pretty tricky, so good luck. > > > > -- > > PHP General Mailing List (http://www.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > > -- > Alex Davies > > This email and any files transmitted with it are confidential and > intended solely for the use of the individual or entity to whom they > are addressed. If you have received this email in error please notify > the sender immediately by e-mail and delete this e-mail permanently. > You should probably use Xdebug to find out what needs that method... -- Kyle Terry | www.kyleterry.com
