Some people who add new hosts rebalance the ring afterward - that rebalancing can look a lot like a shrink.
I also believe, but don’t have time to prove, that enough new hosts can eventually give you a range back (moving it all the way around the ring) - less likely but probably possible. Easiest to just assume that any range movement may resurrect data if you haven’t run cleanup. -- Jeff Jirsa > On Feb 13, 2019, at 12:34 AM, Oleksandr Shulgin > <oleksandr.shul...@zalando.de> wrote: > >> On Wed, Feb 13, 2019 at 5:31 AM Jeff Jirsa <jji...@gmail.com> wrote: > >> The most likely result of not running cleanup is wasted disk space. >> >> The second most likely result is resurrecting deleted data if you do a >> second range movement (expansion, shrink, etc). >> >> If this is bad for you, you should run cleanup now. For many use cases, it’s >> a nonissue. >> >> If you know you’re going to add more hosts, be very sure you run cleanup >> before you do so. > > Jeff, > > Could you please expand a little? Do you mean that adding new hosts can lead > to deleted data resurrection if cleanup isn't done prior to that? > > I would only expect this to be a potential problem if one removes nodes, > since then range ownership can expand, but not with adding nodes, as then > ownership can only shrink. Or am I missing something bigger? > > -- > Alex >
