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Re: [Gluster-devel] Performance question.


From: Chris Johnson
Subject: Re: [Gluster-devel] Performance question.
Date: Wed, 21 Nov 2007 13:26:24 -0500 (EST)

On Wed, 21 Nov 2007, Anand Avati wrote:

     I'll try and find out.

     Also, is it the case that glusterfs will always be noticably
slower than NFS?

Chris,
 what cache-size did you configure in io-cache? Is it possible to share
throughput benchmarks using dd (both read and write) also what is the
io-zone performance at 128kB reclen?

avati

2007/11/21, Chris Johnson <address@hidden>:

On Wed, 21 Nov 2007, Chris Johnson wrote:

Ok, caching and write-behind moved to the client side.  There is some
improvement.


random  random    bkwd  record  stride
               KB  reclen   write rewrite    read    reread    read
write    read rewrite    read   fwrite frewrite   fread  freread
           131072      32     312     312      361      363    1453
322     677     320     753      312      312     369      363

but as you can see it's marginal.  Is this typical, i.e. being an
order of magnitude slower than NFS?

On Wed, 21 Nov 2007, Anand Avati wrote:

    See I asked if there was a philosophy about how to build a stack.
Never got a response until now.

    Caching won't help in the real appication I don't believe.
Mostly it's read, crunch, write.  If I'm wrong here please let me
know.  Although I don't believe it will hurt.  I'll give moving
write-behind and io-cache to the client and see what happens.  Does it
matter how they're stacked, i.e. the which comes first?

You should also be loading io-cache on the client side with a decent
cache-size (like 256MB? depends on how much RAM you have to spare).
this
will help re-read improve a lot.

avati

2007/11/21, Anand Avati <address@hidden>:

Chris,
 you shoud really be loading write-behind on the client side, that is
wht
improves write performance the most. do let us know the results with
writebehind on the client side.

avati

2007/11/21, Chris Johnson <address@hidden>:

      Hi, again,

      I asked about stack building philosophy.  Apparently there
isn't
one.  So I tried a few things.  The configs are down the end here.

      Two systems, CentOS5, both running fuse-devel-2.7.0-1 gluster
enhanced, glusterfs-1.3.5-2.  Both have gigabit ethernet, server runs
a SATABeast.  Currently I ge the following from from iozone.

iozone -aN -r 32k -s 131072k -f /mnt/glusterfs/sdm1/junknstuff


random  random    bkwd  record  stride
               KB  reclen   write rewrite    read    reread    read
write    read rewrite    read   fwrite frewrite   fread  freread
           131072      32     589     587      345      343     818
621     757     624     845      592      591     346      366

Now, a similar test using NFS on a CentOS4.4 system running a 3ware
RAID card gives this

iozone -aN -r 32k -s 131072k -f /space/sake/5/admin/junknstuff


random  random    bkwd  record  stride
               KB  reclen   write rewrite    read    reread    read
write    read rewrite    read   fwrite frewrite   fread  freread
           131072      32      27      26      292
11      11      24     542       9     539       30       28     295
11

And you can see that the NFS system is faster.  Is this because of
the
hardware 3ware RAID or is NFS really that much faster here?  Is there
a better way to stack this that would improve things?  And I tried
with
and without striping.  No noticable difference in gluster
performance.

      Help appreciated.

============  server config

volume brick1
   type storage/posix
   option directory /home/sdm1
end-volume

volume brick2
   type storage/posix
   option directory /home/sdl1
end-volume

volume brick3
   type storage/posix
   option directory /home/sdk1
end-volume

volume brick4
   type storage/posix
   option directory /home/sdk1
end-volume

volume ns-brick
   type storage/posix
   option directory /home/sdk1
end-volume

volume stripe1
  type cluster/stripe
  subvolumes brick1 brick2
# option block-size *:10KB,
end-volume

volume stripe2
  type cluster/stripe
  subvolumes brick3 brick4
# option block-size *:10KB,
end-volume

volume unify0
  type cluster/unify
  subvolumes stripe1 stripe2
  option namespace ns-brick
  option scheduler rr
# option rr.limits.min-disk-free 5
end-volume

volume iot
  type performance/io-threads
  subvolumes unify0
  option thread-count 8
end-volume

volume writebehind
   type performance/write-behind
   option aggregate-size 131072 # in bytes
   subvolumes iot
end-volume

volume readahead
   type performance/read-ahead
#  option page-size 65536 ### in bytes
   option page-size 128kb ### in bytes
#  option page-count 16 ### memory cache size is page-count x
page-size per file
   option page-count 2 ### memory cache size is page-count x
page-size
per file
   subvolumes writebehind
end-volume

volume server
   type protocol/server
   subvolumes readahead
   option transport-type tcp/server     # For TCP/IP transport
#  option client-volume-filename /etc/glusterfs/glusterfs-client.vol
   option auth.ip.readahead.allow *
end-volume


============  client config

volume client
   type protocol/client
   option transport-type tcp/client
   option remote-host xxx.xxx.xxx.xxx
   option remote-subvolume readahead
end-volume



-------------------------------------------------------------------------------

Chris Johnson               |Internet: address@hidden
Systems Administrator       |Web:
http://www.nmr.mgh.harvard.edu/~johnson
<http://www.nmr.mgh.harvard.edu/%7Ejohnson>
NMR Center                  |Voice:    617.726.0949
Mass. General Hospital      |FAX:      617.726.7422
149 (2301) 13th Street      |A compromise is a solution nobody is
happy
with.
Charlestown, MA., 02129 USA |     Observation, Unknown



-------------------------------------------------------------------------------


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--
It always takes longer than you expect, even when you take into
account
Hofstadter's Law.

-- Hofstadter's Law




--
It always takes longer than you expect, even when you take into account
Hofstadter's Law.

-- Hofstadter's Law



-------------------------------------------------------------------------------
Chris Johnson               |Internet: address@hidden
Systems Administrator       |Web:
http://www.nmr.mgh.harvard.edu/~johnson
NMR Center                  |Voice:    617.726.0949
Mass. General Hospital      |FAX:      617.726.7422
149 (2301) 13th Street      |For all sad words of tongue or pen, the
saddest
Charlestown, MA., 02129 USA |are these: "It might have been".  John G.
Whittier

-------------------------------------------------------------------------------





-------------------------------------------------------------------------------
Chris Johnson               |Internet: address@hidden
Systems Administrator       |Web:
http://www.nmr.mgh.harvard.edu/~johnson
NMR Center                  |Voice:    617.726.0949
Mass. General Hospital      |FAX:      617.726.7422
149 (2301) 13th Street      |Fifty percent of all doctors graduated in the
Charlestown, MA., 02129 USA |lower half of the class.  Observation

-------------------------------------------------------------------------------




--
It always takes longer than you expect, even when you take into account
Hofstadter's Law.

-- Hofstadter's Law


------------------------------------------------------------------------------- Chris Johnson |Internet: address@hidden
Systems Administrator       |Web:      http://www.nmr.mgh.harvard.edu/~johnson
NMR Center                  |Voice:    617.726.0949
Mass. General Hospital      |FAX:      617.726.7422
149 (2301) 13th Street      |"A good engineer never reinvents the wheel when
Charlestown, MA., 02129 USA |an existing one with modifications will do." Me -------------------------------------------------------------------------------




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