On Dec 26, 2011, at 11:34 PM, ben slimup wrote: > so in that case does it means that ntp protocol cannot be load balanced at > all??
A load-balancer that provides session affinity based only upon source IP would function to some extent, but keeping track of all that state is vastly more work than generating NTP queries and responses, and going through a load-balancer adds delay that reduces timekeeping quality. Trying to load-balance NTP is like trying to load-balance ICMP pings. It's almost always going to be the wrong approach. > are there any ways to provide load balancing without disturbing ntp roundtrip > proccess? Yes: NTP is already designed with fault-tolerance built in. List multiple NTP servers in the client configuration, and let ntpd handle it from there. If some of the servers go down, or if some are too busy and they drop a query, ntpd on the clients will adjust reachability and continue to work just fine using the other servers. > since i have gotten a lot of devices here , i made a simple design that all > servers have their own public ip adresses. > but my concern is that design is my clients can handle only 4 ntp servers, > and to fit the requirement of 1million synch per poll, > i will need 8 servers at least.. > do you guys have any design idea that can handle such traffic after blackout > for example? Yes, you don't need to do anything. Once ntpd has been running for long enough to have good data, it determines and saves the intrinsic drift of the local clock from "true time" in order to keep the local clock running reasonably well even if all of the servers it was using drop off for a while. My best advice is that you set up a few NTP servers, and run some of your clients against them for a month or two as a trial or test, so that you gain the experience needed to figure out what you need to do for a larger deployment. Regards, -- -Chuck _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
