On Tue, 27 Jan 2015, Mykola Golub wrote: > On Mon, Jan 19, 2015 at 07:17:58AM -0800, Sage Weil wrote: > > On Mon, 19 Jan 2015, Gregory Farnum wrote: > > > On Sun, Jan 18, 2015 at 11:02 PM, Mykola Golub <mgolub@xxxxxxxxxxxx> wrote: > > > > On Sun, Jan 18, 2015 at 10:33:05AM -0800, Sage Weil wrote: > > > >> On Sun, 18 Jan 2015, Mykola Golub wrote: > > > >> > Hi Ceph, > > > >> > > > > >> > Right now, for not a monitor leader, if a received command is not > > > >> > supported locally, but is supported by the leader, it is forwarded to > > > >> > the leader. > > > >> > > > > >> > For the recently added "ceph tell mon.x version" it gives a confusing > > > >> > behavior: if the mon.x is not a leader and does not support "version" > > > >> > command yet, but the leader does, the user will receive the version of > > > >> > the leader, and can't be actually sure about a non leader version. > > > >> > > > > >> > I have a patch that fixes this by checking if the received "version" > > > >> > command is forwarded and returning the error in this case: > > > >> > > > > >> > https://github.com/trociny/ceph/commit/98f835357e378b1c5f05b32ba90a8b8537ba1ad8 > > > >> > > > > >> > But may be we need a more general solution? We might face a similar > > > >> > issue in future, when adding a new command, which is not expected to > > > >> > be forwarded to the leader (like injectargs). > > > >> > > > >> Yeah.. that works for 'version' but not any other 'tell mon ...' command. > > > >> > > > >> I think the way to do it properly going forward is to add a flags field to > > > >> MMonCommand, with a flag NOFORWARD. > > > >> > > > >> That won't help in the version case, so we can combine it with your > > > >> patch... > > > > > > > > Do you mean > > > > > > > > 1) statically adding the NOFORWARD flag to commands definitions in > > > > MonCommands.h (and to the struct MonCommand in Monitor.h), and then > > > > checking for the flag in Monitor::handle_command(), before forwarding > > > > to the leader, or > > > > Hmm, this is a cleaner way to approach your change that specifically > > applies to the new 'version' command. > > > > > > 2) extending librados API, RadosClient::mon_command(), so a user could > > > > set the flag for any sent command she don't want to be forwarded, and > > > > using this flag for 'ceph tell mon.x ...' commands? > > > > ..but I think we also want this, so that *any* 'ceph tell mon.whatever > > ...' command can be flagged to not get forwarded. > > I have created a pull request that implements both: > > https://github.com/ceph/ceph/pull/3496 > > The (2) looks not very useful for now -- I suppose currently the only > command that suffers from the describe problem is "version" and it has > "noforward" hard coded. This might change in future though. Other commands where this would be useful are 'injectargs' and 'mon_status', 'compact', and 'heap'. Made a few other comments on the pull request! Thanks- sage -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
