Agree! When using client timestamp, NTP should be running on them as well.
On Thu, Mar 8, 2018 at 6:24 PM, Jeff Jirsa <[email protected]> wrote: > Clients can race (and go backward), so the more computer answer tends to > be to use LWT/CAS to guarantee state if you have a data model where it > matters. > > -- > Jeff Jirsa > > > On Mar 8, 2018, at 6:18 PM, Dor Laor <[email protected]> wrote: > > While NTP on the servers is important, make sure that you use client > timestamps and > not server. Since the last write wins, the data generator should be the > one setting its timestamp. > > On Thu, Mar 8, 2018 at 2:12 PM, Ben Slater <[email protected]> > wrote: > >> It is important to make sure you are using the same NTP servers across >> your cluster - we used to see relatively frequent NTP issues across our >> fleet using default/public NTP servers until (back in 2015) we implemented >> our own NTP pool (see https://www.instaclustr.c >> om/apache-cassandra-synchronization/ which references some really good >> and detailed posts from logentries.com on the potential issues). >> >> Cheers >> Ben >> >> On Fri, 9 Mar 2018 at 02:07 Michael Shuler <[email protected]> >> wrote: >> >>> As long as your nodes are syncing time using the same method, that >>> should be good. Don't mix daemons, however, since they may sync from >>> different sources. Whether you use ntpd, openntp, ntpsec, chrony isn't >>> really important, since they are all just background daemons to sync the >>> system clock. There is nothing Cassandra-specific. >>> >>> -- >>> Kind regards, >>> Michael >>> >>> On 03/08/2018 04:15 AM, Kyrylo Lebediev wrote: >>> > Hi! >>> > >>> > Recently Amazon announced launch of Amazon Time Sync Service >>> > (https://aws.amazon.com/blogs/aws/keeping-time-with-amazon-t >>> ime-sync-service/) >>> > and now it's AWS-recommended way for time sync on EC2 instances >>> > (https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html). >>> > It's stated there that chrony is faster / more precise than ntpd. >>> > >>> > Nothing to say correct time sync configuration is very important for >>> any >>> > C* setup. >>> > >>> > Does anybody have positive experience using crony, Amazon Time Sync >>> > Service with Cassandra and/or combination of them? >>> > Any concerns regarding chrony + Amazon Time Sync Service + Cassandra? >>> > Are there any chrony best-practices/custom settings for C* setups? >>> > >>> > Thanks, >>> > Kyrill >>> > >>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: [email protected] >>> For additional commands, e-mail: [email protected] >>> >>> -- >> >> >> *Ben Slater* >> >> *Chief Product Officer <https://www.instaclustr.com/>* >> >> <https://www.facebook.com/instaclustr> >> <https://twitter.com/instaclustr> >> <https://www.linkedin.com/company/instaclustr> >> >> Read our latest technical blog posts here >> <https://www.instaclustr.com/blog/>. >> >> This email has been sent on behalf of Instaclustr Pty. Limited >> (Australia) and Instaclustr Inc (USA). >> >> This email and any attachments may contain confidential and legally >> privileged information. If you are not the intended recipient, do not copy >> or disclose its content, but please reply to this email immediately and >> highlight the error to the sender and then immediately delete the message. >> > >
