we don't have those guarantees on EC2. Networks can fluctuate wildly. On Mon, Jul 25, 2011 at 2:00 PM, zGreenfelder <zgreenfel...@gmail.com>wrote:
> > > On Mon, Jul 25, 2011 at 8:51 AM, Paul Loy <ketera...@gmail.com> wrote: > >> As I understand it, this will not quarantee that they are millisecond >> accurate which is what you need for Cassandra to use the correct commit. >> We've seen problems in production and had to rearchitect parts of the system >> due to this even though all servers are NTP synched. >> >> http://www.endruntechnologies.com/faq.htm#How_accurate_is >> >> >> > Perhaps you'd do well to do some more intensive NTP configuration. > Something like: > > outside server(s) <--- 2 local NTP machines (time[01].mydomain) <---- X > number of cassandra servers over lan > > assuming your lan is speedy enough, you should be able to get to the .5 MS > range of sameness (which might still be 100MS off 'real' time, but I don't > think you'd really care about that). > > it might even be worth creating your own NTP LAN that connects all the > machines on an interface separate from Data & Management. > > > -- > Even the Magic 8 ball has an opinion on email clients: Outlook not so good. > -- --------------------------------------------- Paul Loy p...@keteracel.com http://uk.linkedin.com/in/paulloy
