On Wed, 2019-09-11 at 11:30 -0700, Gregory Farnum wrote: > On Tue, Sep 10, 2019 at 3:11 AM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > I've no particular objection here, but I'd prefer Greg's ack before we > > merge it, since he raised earlier concerns. > > You have my acked-by in light of Zheng's comments elsewhere and the > evidence that this actually works in some scenarios. > > Might be nice to at least get far enough to generate tickets based on > your questions in the other thread, though: > I'm not sold yet. Why is this something the client should have to worry about at all? Can we do something on the MDS to better handle this situation? This really feels like we're exposing an implementation detail via mount option. At a bare minimum, if we take this, I'd like to see some documentation. When should a user decide to turn this on or off? There are no guidelines to the use of this thing so far. > On Wed, Sep 11, 2019 at 9:26 AM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > In an ideal world, what should happen in this case? Should we be > > changing MDS policy to forward the request in this situation? > > > > This mount option seems like it's exposing something that is really an > > internal implementation detail to the admin. That might be justified, > > but I'm unclear on why we don't expect more saner behavior from the MDS > > on this? > > I think partly it's that early designs underestimated the cost of > replication and overestimated its utility, but I also thought forwards > were supposed to happen more often than replication so I'm curious why > it's apparently not doing that. > -Greg -- Jeff Layton <jlayton@xxxxxxxxxx>
