Hi DuyHai, Thanks, and that's exactly what I am asking, if NTP goes backward. Actually NTP often does that because clock drift is inevitable.
On Tue, Oct 10, 2017 at 3:13 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > The ballot UUID is obtained using QUORUM agreement between replicas for a > given partition key and we use this TimeUUID ballot as write-time for the > mutation. > > The only scenario where I can see a problem is that NTP goes backward in > time on a QUORUM of replicas, which would break the contract of > monotonicity. I don't know how likely this event is ... > > On Tue, Oct 10, 2017 at 9:07 AM, Daniel Woo <daniel.y....@gmail.com> > wrote: > >> Hi guys, >> >> The ballot UUID should be monotonically increasing on each coordinator, >> but the UUID in cassandra is version 1 (timestamp based), what happens if >> the NTP service adjusts system clock while a two phase paxos prepare/commit >> is in progress? >> >> -- >> Thanks & Regards, >> Daniel >> > > -- Thanks & Regards, Daniel
