This makes a lot more sense. What does TMOF stand for? On Sun, Feb 26, 2017 at 1:01 PM, Benjamin Roth <benjamin.r...@jaumo.com> wrote:
> Hi Seth, > > Repairs can create a lot of tiny SSTables. I also encountered the creation > of so many sstables that the node died because of TMOF. At that time the > affected nodes were REALLY inconsistent. > > One reason can be immense inconsistencies spread over many > partition(-ranges) with a lot of subrange repairs that trigger a lot of > independant streams. Each stream results in a single SSTable that can be > very small. No matter how small it is, it has to be compacted and can cause > a compaction impact that is a lot bigger than expected from a tiny little > table. > > Also consider that there is a theoretical race condition that can cause > repairs even though data is not inconsistent due to "flighing in mutations" > during merkle tree calculation. > > 2017-02-26 20:41 GMT+01:00 Seth Edwards <s...@pubnub.com>: > >> Hello, >> >> We just ran a repair on a keyspace using TWCS and a mixture of TTLs .This >> caused a large proliferation of sstables and compactions. There is likely a >> lot of entropy in this keyspace. I am trying to better understand why this >> is. >> >> I've also read that you may not want to run repairs on short TTL data and >> rely upon other anti-entropy mechanisms to achieve consistency instead. Is >> this generally true? >> >> >> Thanks! >> > > > > -- > Benjamin Roth > Prokurist > > Jaumo GmbH · www.jaumo.com > Wehrstraße 46 · 73035 Göppingen · Germany > Phone +49 7161 304880-6 <+49%207161%203048806> · Fax +49 7161 304880-1 > <+49%207161%203048801> > AG Ulm · HRB 731058 · Managing Director: Jens Kammerer >
