Hi Mingda Wang, On 02/19/2014 10:11 AM, [email protected] wrote: > Zitat von 王明达 <[email protected]>: >> I try add my ntp server to pool, but I found it's score is drop in >> cycles , I >> think it's related to traffic,but the system's load is very low, I didn't >> find >> any error in log, configure file pls see the attachment. How to find the >> bottleneck of the system? Looking forward to your reply. >> >> http://www.pool.ntp.org/scores/114.113.198.166 > > You have a very long round trip time to your peers you get time from. Delay > values > should be below 100ms in today networks, you should maybe look for "closer" > NTP peers.
I saw one of your peers is located in the Netherlands, Europe. That explains the round-trip times. Having stratum 1 peers is nice, but nearby stratum 2 or even a few stratum 3 servers might be a better choice (if I remember right, the pool monitoring system accepts up to stratum 5 servers in the pool). One way to obtain them is via 'host 0.asia.pool.ntp.org' (and '1...', '2...', '3...') multiple times at different times (to allow for DNS-rotation). Then check with 'ntpdate -qp 1 <<ip>>' the stratum and with traceroute (or traceroute6 for IPv6) the number of hops. You can also check their scores and see if their score is stable. > Furthermore the Jitter values are bad which could lead to the strange score > plot. I just looked at the CSV data for the server. The time is reasonable accurate, so the high round-trip time and jitter are not really a problem. But, you have frequently no response at all. This causes the drops in the score (at this time). You need to figure out why the NTP-requests from the monitoring server do not reach your server, or why the answers don't get back. You may have bad internet connectivity or packets may be dropped due to high traffic somewhere in between (or something else...) Perhaps you can check packets from/to the monitoring server with something like tcpdump. Hope this helps! Arnold _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
