On Mon, 14 Sep 2015, GuangYang wrote: > Thanks Sage. That makes sense. Just would like to confirm my understanding: > > Let's say the map for the PG changes from [1, 2, 3] to [1, 2, 4] and 4 is the backfill target (4 may or may not have the info for the PG, which should not matter as long as it is not eligible for log based recovery), here the PG's last_backfill and backfill_info.begin would reset to MIN, same for 4, and the flow would be something like: > 1. 1 scan_range starting from backfill_info.begin for a configured number of entries > 2. 1 query the digest from 4 for the range > 3. Once the digest is back from 4, fill the to_push and to_remove list by comparing the local and remote entries (here we also consider the PG log to capture most recent updates) > 4. If either to_push or to_remove is not empty, push the objects (or remove) to the backfill target. > 5. Move the lack_backfill pointer and continue with step 1. Yep! sage
