themule wrote: > Hello, > I have 3 servers operating at stratum-2, providing time to a small > population of clients (most routers and stratum-3 servers that > redistribute time to their LANs). The only source of time sync are > public NTP servers, and the configuration is based on this document: > http://www.eecis.udel.edu/~mills/ntp/html/notes.html. Each server has > 2 stratum-1 sources (total of 6 distinct servers) and 4 stratum-2 > peers (the other 2 internal servers plus 2 external ones). The reason > for this is mostly the ability to simple disable one external server > when it goes off-sync for some time and still have 3 external sources. > > Now, I know that performance is quite a subjective matter. All we need > is to keep lan servers and clients in sync, with most timestamps > having 1 sec resolution. Currently I see offsets of about +/- 10ms on > ours main NTP servers, with occasional peaks, so let's say performance > is "good enough" for us. > > But sometimes I wonder how good is that on an absolute scale, just out > of curiosity. And of course if it can be somehow improved. I've > plotted graphs from peerstats of the three main servers (ntp1, ntp2, > ntp3), and what really surprises me is that the three servers show > quite different patterns (hardware _is_ quite different tho). > > May someone more experienced than me have a quick look at the graphs > and provide a couple of comments on them? They are here: > http://stats.esiway.net/NTP/ > > I'd like to know how they compare to, say, similar stratum-2 servers. > I've found a few other graphs of running servers on the Internet, but > I can't make real comparisons since they are either stratum-1 servers > or stratum-2 servers right next (same LAN) to a stratum-1 server, and > of course their accurancy is orders of magnitude better. > > TIA, > .TM. >
Well, your stratum two servers are obviously being "jerked around" by your network connection. There's not much that you, or anyone, can do about it; networks, particularly the internet, are like that. "Good enough" is usually enough. If you need or want greater accuracy and stability, try getting a GPS receiver designed for timing service and use it as a reference clock. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
