Raghavendra Talur <rta...@redhat.com> writes: > On Mon, Jul 18, 2016 at 5:48 PM, Markus Armbruster <arm...@redhat.com> > wrote: > >> Prasanna Kalever <pkale...@redhat.com> writes: >> >> > On Mon, Jul 18, 2016 at 2:23 PM, Markus Armbruster <arm...@redhat.com> [...] >> >> This is fine if gluster+rdma never actually worked. I tried to find out >> >> at https://github.com/gluster/glusterfs/blob/master/api/src/glfs.h. >> >> Transport rdma is mentioned there. Does it work? >> > >> > this is transport used for fetching the volume file from the nodes. >> > Which is of type tcp previously and then now it also supports the unix >> > transport. >> > >> > More response from gluster community >> > @http://www.gluster.org/pipermail/gluster-devel/2016-July/050112.html >> >> Quote Raghavendra Talur's reply: >> >> > My understanding is that @transport argumet in >> > glfs_set_volfile_server() is meant for specifying transport used in >> > fetching volfile server, >> > >> >> Yes, @transport arg here is transport to use for fetching volfile. >> >> >> > IIRC which currently supports tcp and unix only... >> > >> Yes, this is correct too. >> >> Here, Raghavendra seems to confirm that only tcp and unix are supported. >> >> > >> > The doc here >> > https://github.com/gluster/glusterfs/blob/master/api/src/glfs.h >> > +166 shows the rdma as well, which is something I cannot digest. >> > >> This is doc written with assumption that rdma would work too. >> >> >> > >> > >> > Can someone correct me ? >> > >> > Have we ever supported volfile fetch over rdma ? >> > >> >> I think no. To test, you would have to set rdma as only transport >> option in >> glusterd.vol and see what happens in volfile fetch. >> >> But here, it sounds like it might work anyway! >> > > Prasanna, Rafi and I tested this. When rdma option is specified, gluster > defaults to tcp silently.
Good to know. Thanks! > I do not like this behavior. Understandable :) >> IMO, fetching volfile over rdma is an overkill and would not be >> required. >> RDMA should be kept only for IO operations. >> >> We should just remove it from the docs. >> >> Don't misunderstand me, I'm very much in favor of removing the rdma >> transport here. All I'm trying to do is figure out what backward >> compatibility ramifications that might have. >> >> If protocol gluster+rdma has never actually worked, we can safely remove >> it. >> >> But if it happens to work even though it isn't really supported, the >> situation is complicated. Dropping it might break working setups. >> Could perhaps be justified by "your setup works, but it's unsupported, >> and I'm forcing you to switch to a supported setup now, before you come >> to grief." >> >> If it used to work but no more, or if it will stop working, it's >> differently complicated. Dropping it would still break working setups, >> but they'd be bound to break anyway. >> >> Thus, my questions: does protocol gluster+rdma work before your patch? >> If no, did it ever work? "I don't know" is an acceptable answer to the >> latter question, but not so much to the former, because that one is >> easily testable. >> > > Yes, it appeared to user that the option worked and removing the option > would break such setups. I agree with Markus that removing the option right > away would hurt users and we should follow a deprecation strategy for > backward compatibility. Since Gluster maps rdma to tcp, I think the following should do: * If the user asks for file=gluster+rdma:..., print a warning and use file=gluster+tcp:... instead. Deprecate this usage. * Don't add transport 'rdma' to the QAPI schema. What do you think? [...]
