On Wed, Jul 15, 2020 at 1:41 PM Budai Laszlo <laszlo.budai(a)gmail.com> wrote: Clients subscribe to map updates, either continuous or one-time. The monitor keeps track of clients that asked for continuous updates and whenever a new map of the respective type is published, sends it to those clients (for osdmaps, what gets sent is an incremental on top of the previous osdmap as the full osdmap can be quite large). Most clients don't subscribe to continuous map updates and instead rely on lazy map propagation. When an OSD receives a request from a client with an old osdmap, it will send an incremental along with the reply (or instead of the reply, if, according to the current osdmap, the request should have been directed to a different OSD). The client processes the incremental and resends the request if needed. Thanks, Ilya