[Gluster-devel] Performance problems in our web server setup

[Anand Avati]

Bernhard,
 Thanks for trying glusterfs! I have some questions/suggestions -

1. The read-ahead translator in glusterfs--mainline--2.4 used an 'always
aggressive' mode. Probably setting a lower page-count (2?) and a page-size
of 131072 can help. If you are using gigabit ethernet, glusterfs can peak
1Gbps even without read-ahead. So you could infact try without read-ahead as
well.

2. I would suggest you to try if the latest TLA on
glusterfs--mainline--2.5works well for you, and if it does, use the
io-cache translator on the
client side. For your scenario (serving lot of small files read-only)
io-cache should do a lot of good. If you can have a trial setup and see how
well io-cache helps you, we will be very much in knowing your results (and
if possible, some numbers)

3. Please try the patched fuse available at -
http://ftp.zresearch.com/pub/gluster/glusterfs/fuse/fuse-2.7.0-glfs1.tar.gz
   This patched fuse greatly improves read performance, and we expect it to
complement the io-cache feature very well.

4. About using multiple tcp connections, the load-balancer feature is in our
roadmap where you can load balance over two network interfaces, or just
exploit multiple tcp connections over the same network interface. You will
have to wait for the 1.4 release for this.

thanks,
avati

2007/7/24, Bernhard J. M. Grün <bernhard.gruen at googlemail.com>:
>
> Hello!
>
> We experience some performance problems with our setup at the moment.
> And we would be happy if someone of you could help us out.
> This is our setup:
> Two clients connect to two servers that share the same data via AFR.
> The two servers hold about 13.000.000 smaller image files that are
> sent out to the web via the two clients.
> First I'll show you the configuration of the servers:
> volume brick
>   type storage/posix                   # POSIX FS translator
>   option directory /media/storage       # Export this directory
> end-volume
>
> volume iothreads    #iothreads can give performance a boost
>    type performance/io-threads
>    option thread-count 16
>    subvolumes brick
> end-volume
>
> ### Add network serving capability to above brick.
> volume server
>   type protocol/server
>   option transport-type tcp/server     # For TCP/IP transport
>   option listen-port 6996              # Default is 6996
>   option client-volume-filename /opt/glusterfs/etc/glusterfs/client.vol
>   subvolumes iothreads
>   option auth.ip.iothreads.allow * # Allow access to "brick" volume
> end-volume
>
> Now the configuration of the clients:
> ### Add client feature and attach to remote subvolume
> volume client1
>   type protocol/client
>   option transport-type tcp/client     # for TCP/IP transport
>   option remote-host 10.1.1.13     # IP address of the remote brick
>   option remote-port 6996              # default server port is 6996
>   option remote-subvolume iothreads        # name of the remote volume
> end-volume
>
> ### Add client feature and attach to remote subvolume
> volume client2
>   type protocol/client
>   option transport-type tcp/client     # for TCP/IP transport
>   option remote-host 10.1.1.14     # IP address of the remote brick
>   option remote-port 6996              # default server port is 6996
>   option remote-subvolume iothreads        # name of the remote volume
> end-volume
>
> volume afrbricks
>   type cluster/afr
>   subvolumes client1 client2
>   option replicate *:2
> end-volume
>
> volume iothreads    #iothreads can give performance a boost
>    type performance/io-threads
>    option thread-count 8
>    subvolumes afrbricks
> end-volume
>
> ### Add writeback feature
> volume writeback
>   type performance/write-behind
>   option aggregate-size 0  # unit in bytes
>   subvolumes iothreads
> end-volume
>
> ### Add readahead feature
> volume bricks
>   type performance/read-ahead
>   option page-size 65536     # unit in bytes
>   option page-count 16       # cache per file  = (page-count x page-size)
>   subvolumes writeback
> end-volume
>
> We use Lighttpd as web server to handle the web traffic and it seems
> that the image loading is quite slow. Also the used bandwidth between
> one client and its corresponding AFR-Server is low - about 12 MBit/s
> over a 1 GBit line. So there must be a bottleneck in our
> configuration. Maybe you can help us.
> At the moment we are using 1.3.0 (mainline--2.4 patch-131). At the
> moment we can't easily switch to mainline--2.5 because the servers are
> under high load.
>
> We also have seen that each client uses only one connection to each
> server. In my opinion this means that the iothreads subvolume on the
> client is (nearly) useless. Wouldn't it be better to establish more
> than just one connection to each server?
>
> Many thanks in advance
>
> Bernhard J. M. Grün
>
>
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>



-- 
Anand V. Avati