On Mon, 19 Feb 2018, John Spray wrote: > On Mon, Feb 19, 2018 at 5:28 PM, Gregory Farnum <gfarnum@xxxxxxxxxx> wrote: > > On Mon, Feb 19, 2018 at 7:27 AM, John Spray <jspray@xxxxxxxxxx> wrote: > >> On Thu, Feb 15, 2018 at 6:52 PM, David Disseldorp <ddiss@xxxxxxx> wrote: > >>> Hi Jeff, > >>> > >>> On Thu, 15 Feb 2018 13:09:45 -0500, Jeff Layton wrote: > >>> > >>>> IIUC, if the program (samba in this case) dies, and then is restarted > >>>> (maybe host reboots?), it'll get a new instance_guid, right? Or am I > >>>> misunderstanding what rados_get_instance_id will return here? > >>> > >>> Yes, that's right. On smbd restart it'll reconnect and get a new > >>> instance ID. The hostname is carried in the metadata, which makes it a > >>> little easier to identify what's going on from the Ceph side. > >> > >> As you say, the hostname is what most people are interested in most of > >> the time anyway. > >> > >> Using a guid here will also going to be similar to what people see > >> when running Ceph services in auto-scaled groups of Kubernetes > >> containers -- lovingly hand-named daemons will be a thing of the past, > >> and people will be dealing either with an ephemeral ID, or with the > >> hostname from the metadata. > >> > >> The part where dead instances stick around in the status until they > >> time out is annoying. In container environments we will need some > >> logic for culling them when the container dies. In other environments > >> we would either need to add the ability to do the explicit naming of > >> the daemon, or just put up with the stale entries. > > > > You know, OSDs report to the monitor when they’re going down so that > > their peers don’t need to wait through a timeout period. Should we > > consider doing the same when a declared service shuts down? > > Yes, absolutely -- my head was stuck in the worst case (general case) path. > > Need a new shutdown message (or flag on one of the existing messages) > and MgrClient should send it in ::shutdown if session && > service_daemon. This will cause a little shutdown delay in librados, > but I think it's acceptable as it's only for service_daemon users. > http://tracker.ceph.com/issues/23042 Yes! https://trello.com/c/wZdg9Yh8/326-mgrclient-deregister-on-shutdown sage
