[PVFS-users] mmargo

[Martin Margo]

Ron,

Thanks for the heads up. I thought that the January patch will fix the  
problem, at least some other folks in this list declared that. What are  
your workaround for this problem?

-Martin
On Apr 2, 2004, at 2:18 PM, Ron W. Green wrote:

> we're using 1.6.2 with the january patch and are seeing these enqueue  
> messages.
>
> if it helps, we have 236 client nodes talking to the one mgr node, and  
> have 6 iod nodes.  Is it possible that we need a much deeper queue  
> depth to accommodate long latencies in talking to the mgr?  Are the  
> clients spilling out of their local queues with requests waiting on  
> mgr?  I suspect it may be a scaling issue.
>
> thanks, I do appreciate the work being done on PVFS.  It is improving.
>
> ron
>
> Nathan Poznick wrote:
>
>> _______________________________________________
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>> http://www.beowulf-underground.org/mailman/listinfo/pvfs-users
>>
>>
>>
>> ---------------------------------------------------------------------- 
>> --
>>
>> Date:
>> Fri, 2 Apr 2004 10:27:54 -0700
>>
>>
>> ---------------------------------------------------------------------- 
>> --
>>
>> Thus spake Ron W. Green:
>>
>>> Martin,
>>>
>>> We seem to get those "failed on enqueue" quite often.  Of course,  
>>> our cluster is much bigger too.  I've scratched my head on this, and  
>>> looked at the code.  The best I can tell it is when the pvfs client  
>>> attempts a metadata operation to the mgr node.  I suspect that the  
>>> mgr is slow in responding and/or has run out of queueing space to  
>>> enqueue the metadata operation request (create or stat).
>>>
>>> Anyone on the list know if mgr has a fixed queue size?  Or can we  
>>> jack up the client timeouts?  Multithread mgr?
>>>
>>> From our testing we're quite convinced the problem lies in mgr, that  
>>> it can't keep up with metadata requests from the clients.
>>>
>>
>> Actually those messages are not referring to any sort of queuing on  
>> the
>> manager at all - they refer to the pvfsdev_enqueue/dequeue functions  
>> in
>> the kernel module which add/remove messages from the /dev/pvfs-req
>> device.
>>
>>
>>
>
> -- 
> Ron W. Green
> rwgree at sandia.gov
> +1-505-284-1600
>
> Sr. Engineer, ICC Applications Support
>
>
>
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