On 11/03/09 22:05, Chris Hastie wrote: > Can anyone clarify which of ntp's various counters is best for counting > queries received? > > The nearest thing I've found to documentation on ntpdc's sysstats is the > description of the various sysstats from > http://doc.ntp.org/4.2.4/monopt.html > > This suggests that packets received is a total, including responses to > queries we've sent. So should I be looking at packets received - packets > processed? >
I've dug a little further into this and things don't seem to be nearly as simple as I had hoped. I happened to have access to a machine providing time services to a small LAN and nothing else. Comparing the outputs of sysstats and monlist (which is a blissfully short list) things start to make a bit more sense. Packets received includes packets received over the loop back interface. Which includes a good few packets everytime someone does an ntpq -p or ntpdc -c sysinfo on the local machine. Which if you're using any munin plugins to monitor a machine is every 5 minutes. On my pool servers (all at 256k) this represents a very significant proportion of all packets. It seems that these packets are not counted in the 'current version' and 'previous version' stats though. So summing these two figures appears to give a reasonable indication of the number of queries, both ways. The 'packets processed' figure does reflect the number of packets received in response to queries sent to peers. So the number of queries actually received from external sources can be gauged from current version + previous version - packets processed. These figures are from a pool server set at 256k bandwidth, with monitoring by both munin and another script making several ntpdc / ntpq queries every five minutes: $ ntpdc -c sysstats time since restart: 2717234 time since reset: 2717234 packets received: 3474038 packets processed: 33628 current version: 149849 previous version: 626055 bad version: 0 access denied: 0 bad length or format: 0 bad authentication: 23 rate exceeded: 0 This gives about 775904 packets from outside, less the 33628 that are response to our queries, leaving 742276. Which is only 21.3% of the total packets received figure. And only about 0.27 qps. _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
