Re: [Moosefs-users] A problem of reading the same file at the same moment

[Michał B. <mic...@ge...>]

Hi Laurent!

If master doesn't take full 100% of CPU it would work even better as one thread. Generally speaking multithreading is often overestimated. Please have a look at this article: http://www.eecs.berkeley.edu/Pubs/TechRpts/2006/EECS-2006-1.pdf


Regards
Michał 

-----Original Message-----
From: Laurent Wandrebeck [mailto:lw...@hy...] 
Sent: Friday, November 26, 2010 12:00 PM
To: moo...@li...
Subject: Re: [Moosefs-users] A problem of reading the same file at the same moment

On Thu, 25 Nov 2010 10:55:03 +0100
Michał Borychowski <mic...@ge...> wrote:

> Hi!
> 
> As written on http://www.moosefs.org/moosefs-faq.html#goal increasing goal may only increase the reading speed under certain conditions. You can just try increasing the goal, wait for the replication and see if it helps.
I'm wondering if such a behaviour could be due to mfsmaster being a monothread program. Thus, in high-load cases, the master being busy answering a request kind of queues the others, being a performance bottleneck by adding latency, preventing one than one request to be worked on at the same time.
Comments ?
--
Laurent Wandrebeck
HYGEOS, Earth Observation Department / Observation de la Terre Euratechnologies
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