[Gluster-users] Writing/reading from local server first in AFR pair

Stas Oskin stas.oskin at gmail.com
Thu Apr 2 08:56:18 UTC 2009


If I have 2 servers in AFR pair, each of them is both client and server,
what is the option to make each server read/write from itself first?

I found an option:

   - *read-subvolume (default: none)*

 The value of this option must be the name of a subvolume. If given, all
read operations are sent to only the specified subvolume, instead of being
balanced across all subvolumes.
But it seems it might actually lower the performance, deducted from here:

"All operations that do not modify the file or directory are sent to all the
subvolumes and the *first successful reply is returned to the application*.
The read() system call (reading data from a file) is an exception. For
read() calls, AFR tries to do *load balancing by sending all reads from a
particular file to a particular server*.

The read algorithm is also affected by the option read-subvolume; see below
for details."
Is it correct, and how this server is determined?

Also, should I use the above option, or let GlsuterFS to decide for himself?

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://supercolony.gluster.org/pipermail/gluster-users/attachments/20090402/335b4621/attachment.html>

More information about the Gluster-users mailing list