[Gluster-devel] Blocking client when server is down

[Martin Fick]

--- On Wed, 12/31/08, Raghavendra G <raghavendra.hg at gmail.com> wrote:

> On Wed, Dec 31, 2008 at 9:03 AM, Martin Fick
> <mogulguy at yahoo.com> wrote:
> > The simplest case seems to be # 1, simply wait for the connection to
> > reestablish itself and retry to submit the protocol to the wire.  I hacked a
> > simple implementation of this (looping in protocol_client_xfer until the
> > connection is reestablished without holding the lock) which seems to work,
> > but I have no clue if it is correct. ;)  I will attach it below.
> 
> 
> blocking the protocol_client_xfer till the server comes up is not good
> always. It may not make any difference in a simple client/server setup. But
> in a setup consisting of cluster translators, say afr, this would lead to
> glusterfs getting blocked on trying to send requests to the server which is
> down, though the request can be fulfilled from the other server(s) which
> is(are) up.
 
Good point, if I understand correctly what you are saying, AFR does not process requests to subvolumes in parallel and therefore would not know when to consider a subvolume "down" and move onto the next one?  Do you forsee any other problems if this blocking behavior were optional and simply not used with AFR?

Thanks for your comments,   

-Martin