nagios and pthreads

Christophe Yayon lists at nbux.com
Wed Jul 13 12:17:24 GMT 2005


Hi,

Yes but if i understand, there is a bug in libc_r on FreeBSD ?


> Hi Christophe,
>
> a quick glance at the archives whould have helped you.
>
>> i know that we add already discuss about this problem, but is there any
>> solution for this problem ?
>>
>> ---
>> What's section on nagios website
>> "FreeBSD and threads. On FreeBSD there's a native user-level
>> implementation of threads called 'pthread' and there's also an optional
>> ports collection 'linuxthreads' that uses kernel hooks. Some folks from
>> Yahoo! have reported that using the pthread library causes Nagios to
>> pause
>> under heavy I/O load, causing some service check results to be lost.
>> Switching to linuxthreads seems to help this problem, but not fix it.
>> The
>> lock happens in liblthread's __pthread_acquire() - it can't ever acquire
>> the spinlock. It happens when the main thread forks to execute an active
>> check. On the second fork to create the grandchild, the grandchild is
>> created by fork, but never returns from liblthread's fork wrapper,
>> because
>> it's stuck in __pthread_acquire(). Maybe some FreeBSD users can help out
>> with this problem."
>> ---
>>
>>
>> I have just upgraded to 5.4-STABLE but i encountered again the problem.
>> Sometimes, there is a nagios forked child process which consume 100% of
>> CPU.
>> i have heard that there was perhaps a problem with libc_r reported by
>> Luigi Rizzo on this list 06/22/2005, but no news since this date...
>>
>> My workaround is to have a cron job which run every hour and check if
>> there is a bad nagios process and kill it... i know it's very ugly...
>>
>> Do you any solution or what could i do to get more trace when it happen
>> ?
>> sorry, but i am not familiar with ktrace like tools... If someone could
>> help me to help nagios community on freebsd ;-) ?
>>
>> Thanks in advance.
>
> This thread should countain some answers :
> http://lists.freebsd.org/pipermail/freebsd-hackers/2005-June/012435.html
>
> Regards,
> --
> Jeremie Le Hen
> < jeremie at le-hen dot org >< ttz at chchile dot org >
>





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