High volume updates to a single key in a distributed system that relies on a timestamp for conflict resolution is not a particularly great idea. If you ever do this from multiple clients you'll find unexpected results at least some of the time.
On Tue, Dec 15, 2015 at 12:41 PM Paulo Motta <pauloricard...@gmail.com> wrote: > > We are using 2.1.7.1 > > Then you should be able to use the java driver timestamp generators. > > > So, we need to look for clock sync issues between nodes in our ring? > How close do they need to be? > > millisecond precision since that is the server precision for timestamps, > so probably NTP should do the job. if your application have submillisecond > updates in the same partitions, you'd probably need to use client-side > timestamps anyway, since they allow setting timestamps with sub-ms > precision. > > > Very cool! If we have multiple nodes in our application, I suppose > *their* clocks will have to be sync'ed for this to work, right? > > correct, you may also use ntp to synchronize clocks between clients. > > > 2015-12-15 12:19 GMT-08:00 James Carman <ja...@carmanconsulting.com>: > >> >> >> On Tue, Dec 15, 2015 at 2:57 PM Paulo Motta <pauloricard...@gmail.com> >> wrote: >> >>> What cassandra and driver versions are you running? >>> >>> >> We are using 2.1.7.1 >> >> >>> It may be that the second update is getting the same timestamp as the >>> first, or even a lower timestamp if it's being processed by another server >>> with unsynced clock, so that update may be getting lost. >>> >>> >> So, we need to look for clock sync issues between nodes in our ring? How >> close do they need to be? >> >> >>> If you have high frequency updates in the same partition from the same >>> client you should probably use client-side timestamps with a configured >>> timestamp generator on the driver, available in Cassandra 2.1 and Java >>> driver 2.1.2, and default in java driver 3.0. >>> >>> >> Very cool! If we have multiple nodes in our application, I suppose >> *their* clocks will have to be sync'ed for this to work, right? >> > >
