Issue with memcached - cpu pegged and no response

[Steven Grimm]

14 out of 16G should be fine provided the machine isn't doing anything 
else and the number of connections is under a few thousand. We run a 
similar configuration.

Also, attaching to the process with gdb and using the "where" command 
will most likely be more useful than strace, especially if the program 
is caught in an infinite loop and isn't making any system calls (in 
which case strace won't output anything at all.)

-Steve


Jeremy wrote:
> Next time it happens I can get an strace out of the process but that could
> be a couple weeks until it occurs again.
>
> Is there any issue with the amount of memory I'm dedicating?  The machine
> has a total of 16gigs and I'm giving 14 of that to memcached.
>
> In our older machines, running an older version of memcached, we run
> multiple instances.  Is there any advantage to that?  I was hoping to get
> away from having to run multiple instances.
>
> Thanks
> -jeremy
>
>
> On 11/12/06 1:24 AM, "Steven Grimm" <sgrimm at facebook.com> wrote:
>
>   
>> Can you attach a debugger to it and get a stack trace? It would help to
>> know where in the code it's hanging/looping.
>>
>> -Steve
>>
>>
>> Jeremy wrote:
>>     
>>> We've been having an issue with memcached 1.2.0 on Fedora Core 5 on am 64bit
>>> AMD with 16gigs of memory.
>>>
>>> Memcached is running with the following parameters:
>>>
>>> memcached -d -p 11211 -u nobody -c 1024 -m 14336
>>>
>>> About every two weeks we'll run into a situation where memcached will lock
>>> up with 100% cpu utilization and become unresponsive.  Only work around is
>>> to restart the daemon at which point we loose our cache.
>>>
>>> Is there any known issues around this?  The interesting thing from our side
>>> is that this has happened on the same exact machine 4 times now, while we
>>> have another machine in the same cluster that has been running with no
>>> problems at all.  Exact same configuration.  Nothing from the OS indicates a
>>> hardware problem.
>>>
>>> Please let me know what other information is important in helping to debug
>>> this problem.
>>>
>>> Thank You
>>> -jeremy
>>>
>>>
>>>   
>>>       
>
>
>   

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