Hi Terje,
if i do not use nat how can i route private adresse to internet ?, i do not want to use ipv6. also i m planning to 2 boxes with 3 card on each site, how can i load balance between site if i m do not use round robin? Thank for your support > From: "terje.mathisen at tmsw.no"@ntp.org > To: [email protected] > Date: Thu, 22 Dec 2011 12:44:07 +0100 > Subject: Re: [ntp:questions] ntp server pool advice > > ben slimup wrote: > > > > Thank for prompt answer Chris, > > > > Unfortunately, this ntp network should give time to specific clients > > devices and not anyone on the public network. > > > > according to your advice, better not using load balancer, thats good > > how to load balance between ntp server if i do not use round robin? > > if all client choosing the same server then the ntp server will be > > overload. is it a problem if for example client 1 poll or synch with > > server 1 , and then with server 2 , etc...? or udp roundtrip comes > > each time from different ntp server? how many ntp servers should be > > needed to handle that much request knowing that each card handle > > 10,000 request per sec? > > First, each client should have at least 4 configured servers, so you can > use the same ntp.conf file for all of them. > > Second, if you really can handle 10K requests/second per card, then that > means that you can handle 640K clients per card, with worst-case polling. > > I.e. servers capable of 10K/second should handle your expected load just > fine, even though a proper (FreeBSD-based) 1U server with a GPS will > serve even more clients with better time performance. > > Terje > > > > much appreciate your expertize > > > > cheers > > > >> From: [email protected] Date: Wed, 21 Dec 2011 19:43:53 > >> -0800 Subject: Re: [ntp:questions] ntp server pool advice To: > >> [email protected] > >> > >> On Wed, Dec 21, 2011 at 5:07 PM, ben slimup<[email protected]> > >> wrote: > >>> > >>> Dear all, > >>> > >>> Thank you very much for support, > >>> > >>> i do not have 1000,000 client, i need those ntp servers to serve > >>> a load between 100000 to 1000000 clients over a public network > >>> with an accuracy of 100ms > >>> > >>> those clients will use dns round robin to resolve 4 external ip, > >>> 2 IPs on each site. i have 4 servers with 4 ntp server slot card > >>> each ( meinberg M900) 1 ntp server card can support 10,000 > >>> request. > >> > >> First off the good news. 100ms is an "easy" spec to meet you can > >> do this without a lot of effort. > >> > >> Don't let the outside world "see" your meinberg servers. Build > >> out a layer of "statum 2" servers and expose those to your clients. > >> 1M clients is a lot for the little 386 class CPU that is in the > >> meinberg box. > >> > >> I still don't understand, Why do all those NTP clients need to go > >> to your NTP servers. Why can't they use any they like? Are your > >> servers doing something special? > >> > >> Also know that EACH client needs to be configured to see multiple > >> NTP servers. practically three servers is a minimum but others > >> will argue for more for five > >> > >> A would not use load balancing for NTP servers. With NTP it > >> does not matter at all if a server crashes. The clients are all > >> configure to use five servers and if one crashes they will do fine > >> using four. If you expose four, large robust servers one on each of > >> your four IP addresses then you will be fine, even if one fails you > >> will be fine. The clients will notice the failure and continue on > >> using the remaining three. > >> > >> > >> I technical question for the list: Would Round Robin load > >> balancing even work. I think it would introduce so much jitter the > >> server would be usless. I think you have to be sure that each > >> time a client pools a server at a given IP address it polls the > >> same physical server. > >> > >> Chris Albertson Redondo Beach, California > > > -- > - <Terje.Mathisen at tmsw.no> > "almost all programming can be viewed as an exercise in caching" > > _______________________________________________ > questions mailing list > [email protected] > http://lists.ntp.org/listinfo/questions _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
