[Gluster-users] glusterfs performance

Harald Stürzebecher haralds at cs.tu-berlin.de
Thu Sep 18 20:27:37 UTC 2008


2008/9/18 Graeme <graeme at sudo.ca>:
> Hi all,
> Just doing some initial testing on glusterfs (1.3.10, Debian packages),
> and I'm somewhat underwhelmed with the performance. I setup up a test
> AFR and a test Unify config with two systems connected by a local,
> managed gigabit switch. My configs have POSIX locking, read-ahead,
> write-behind, and threaded i/o enabled (in that order) on the server
> side. I then compared bonnie output on the raw filesystems to the
> gluster output.
> Machine 1: 72 MB/sec block write, 72MB/sec block read, 29 MB/sec block
> rewrite.
> Machine 2: 36 MB/sec block write, 72MB/sec block read, 21 MB/sec block
> rewrite.
> gluster-AFR: 22 MB/sec block write, 24 MB/sec block read, 9 MB/sec block
> rewrite.
> gluster-Unify (ALU scheduler): 21 MB/sec, 20 MB/sec block read, 8.8
> MB/sec block rewrite.
> The file operation speeds on the initial machines were in thousands to
> tens of thousands of operations a second. On both glusterfs configs they
> were in the hundreds of ops/sec. The client I was testing on was Machine
> 1, since it had the higher overall performance and was under less load.
> Is this expected performance with gluster for a small number of nodes on
> TCP/IP? Or am I missing some critical piece of configuration? In
> particular, I thought that in an AFR config the client was supposed to
> automatically stripe read requests across available volumes, but the
> read performance doesn't seem to indicate that's happening, considering
> the requests it sends to itself should be able to get close to its
> normal ~70MB/sec rate.
> Any tips would be appreciated.  :)

And I have some for you...
Considering my limited experience with GlusterFS I hope that at least
some of my suggestions apply to your problem: :)

- telling GlusterFS to always read from local volume:


"  # option read-subvolume brick2   # by default reads are scheduled
from all subvolumes"

- making sure it's not your network that kills performance:
Do you know the maximum throughput of your network connection? Might
the bottleneck be there? I'd try iperf
(http://dast.nlanr.net/projects/Iperf/) or something like that and/or
run some tests with bonnie on a NFS or CIFS share.
Do you have a machine with two local disks available? In that case I'd
try a configuration completely without a physical network, too.

- compiling the latest version from source for testing:
GlusterFS 1.4 is supposed to bring big improvements for small files:


"#  binary protocol - bit level protocol headers (huge improvement in
performance for small files) "

Harald Stürzebecher

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