Hey Saurabh, We're actually preparing for this ourselves and spinning up our own NTP server pool. The public NTP pools have a lot of drift and should not be relied upon for cluster technology that is sensitive to time skew like C*.
The folks at Logentries did a great write up about this which we used as a guide. - https://blog.logentries.com/2014/03/synchronizing-clocks-in-a-cassandra-cluster-pt-1-the-problem/ - https://blog.logentries.com/2014/03/synchronizing-clocks-in-a-cassandra-cluster-pt-2-solutions/ -Mark On Tue, Mar 31, 2015 at 5:59 PM, Saurabh Sethi <saurabh_se...@symantec.com> wrote: > That’s what I found out that the clocks were not in sync. > > But I have setup NTP on all 3 nodes and would expect the clocks to be in > sync. > > From: Nate McCall <n...@thelastpickle.com> > Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org> > Date: Tuesday, March 31, 2015 at 2:50 PM > To: Cassandra Users <user@cassandra.apache.org> > Subject: Re: Column value not getting updated > > You would see that if the servers' clocks were out of sync. > > Make sure the time on the servers is in sync or set the client timestamps > explicitly. > > On Tue, Mar 31, 2015 at 3:23 PM, Saurabh Sethi <saurabh_se...@symantec.com > > wrote: > >> I have written a unit test that creates a column family, inserts a row in >> that column family and then updates the value of one of the columns. >> >> After updating, unit test immediately tries to read the updated value for >> that column, but Cassandra returns the old value. >> >> - I am using QueryBuilder API and not CQL directly. >> - I am using the consistency level of QUORUM for everything – insert, >> update and read. >> - Cassandra is running as a 3 node cluster with replication factor of >> 3. >> >> >> Anyone has any idea what is going on here? >> >> Thanks, >> Saurabh >> > > > > -- > ----------------- > Nate McCall > Austin, TX > @zznate > > Co-Founder & Sr. Technical Consultant > Apache Cassandra Consulting > http://www.thelastpickle.com >
