[Gluster-users] State of Gluster project

[Stephan von Krawczynski]

On Thu, 18 Jun 2020 13:06:51 +0400
Dmitry Melekhov <dm at belkam.com> wrote:

> 18.06.2020 12:54, Stephan von Krawczynski пишет:
> >
> > _FS IN USERSPACE IS SH*T_  - understand that.
> >  
> 
> we use qemu and it uses gfapi... :-)

And exactly this kind of "insight" is base of my critics. gfapi is _userspace_
on client (given, without fuse), but does not at all handle the basic glusterfs
problem: the need to go through _userspace_ on _server_.
Simply look at the docs here and understand where the work should have been
done:

https://www.humblec.com/libgfapi-interface-glusterfs/

On the server you have to go from kernel-space network to userspace glusterfs
back to kernel-space underlying fs. So gfapi only eliminates one of two major
problems. Comparing performance to NFS on ZFS shows the flaw.
If it was implemented like it should you would have almost _no_ difference,
because you would be able to split up the two network paths to gluster servers
(for a setup with two) on different switches and network cards on client. So
for reading it should be as fast, for writing you may calculate a (very) small
loss.

-- 
Regards,
Stephan