On Sun, Feb 24, 2019 at 3:42 PM Xuehan Xu <xxhdx1985126@xxxxxxxxx> wrote: > > Hi, everyone. > > After a year of cephfs experience, we find QoS, especially metadata > operation QoS, an inevitable requirement for the large-scale > application of CephFS as we don't wan't a small number of clients to > use up all MDS resources. > > Since the MDS doesn't have a QoS support for now, we think maybe we > can implement some kind of client-side throttling of metadata > operations which should meet our requirements mentioned above and be > easy to implement. We plan to implement such a mechanism as part of > the current Quota mechanism to give users the ability to limit, in > addition to the file number or disk space usage, how many metadata > operations can be done per second for a single client under a specific > directory. Is this the right way to go? > client doesn't know global metadata load. how does it avoid throttling while global load is relatively low? > And, after the implementation of this client-side throttling, we > might, as well, seek to find a way to do the real metadata operation > QoS, is dmclock a good algorithm for file system metadata op QoS? > > Thanks for very mych:-)
