[ntp:questions] Type 28 driver (gpsd, SHM) - understanding "flag1"
Folks, I'm looking at: http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver28.html and wanting to be sure that I understand flag1 correctly. The situation is starting a computer which has no real-time clock, and has been down for a day. This computer is in the middle of nowhere, and has a GPS and PPS as reference clocks, using the type 22 and type 28 drivers. By observation, the type 22 (PPS) driver won't kick in until the type 28 (SHM/gpsd) driver is valid, but also by observation with no flags set it seems that the type 28 driver never syncs at all, even though valid GPS data is present. My reading of that page is: - the default, flag1 = 0 or absent, and no time2 set, NTP will not kick in unless the local clock is within 4 hours of the GPS time. It seems that even with -g as an ntpd parameter, which /should/ allow a large initial offset NTP won't kick in. In the computer in question, the difference is likely to be in excess of 24 hours, so NTP will not attempt to correct the clock. This is not the desired behaviour! Is my understanding correct? Would the correct thing to do in such circumstances be to set flag1 = 1 so that the difference limit is ignored? I ask what may be an obvious question as I appear to have difficulty in reading the page. Perhaps old age, I hope nothing more! I suppose I had expect the "-g" to override other sanity checks. -- Thanks, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 21/02/2015 07:04, William Unruh wrote: [] orphan mode is about a group of computers. "Orphan Mode allows a group of ntpd processes to automonously select a leader in the event that all real time sources become unreachable (i.e. are inaccessible)." chrony's is that you can enter the time by hand (Ie, by typing a current time and hitting enter) on a single machine. You are the "remote clock". Now, how useful that is now adays is open to question, but in the past with telephone modems and flaky connections it was worth something. And if you are setting up something on the Hebrides or on a buoy in the Atlantic where no connection of anykind is possible, it could be useful. Ie, it IS different from orphan mode. "Things chronyd can do that ntpd can?t: chronyd provides support for isolated networks whether the only method of time correction is manual entry (e.g. by the administrator looking at a clock)." The claim is for "networks", not single machines. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-21, Paul wrote: > On Fri, Feb 20, 2015 at 3:23 PM, William Unruh wrote: > >> ??? how do assume that the chrony docs do not tell the truth? ^ you > > > I don't understand that sentence. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-21, David Taylor wrote: > On 20/02/2015 20:22, William Unruh wrote: > [] >> No. The local clock simply trusts the time (Ie all offsets are defined >> to be zero) chrony takes the time as entered by hand by the operator and >> uses that to determine the offset. Of course that will not be terribly >> accurate ( a second is probably good), but if you are disconnected for a >> month, a second is probably pretty good accuracy. > > In practice, how does that differ from orphan mode? I think that > statement on behalf of chrony needs to be clarified as it may be misleading. orphan mode is about a group of computers. "Orphan Mode allows a group of ntpd processes to automonously select a leader in the event that all real time sources become unreachable (i.e. are inaccessible)." chrony's is that you can enter the time by hand (Ie, by typing a current time and hitting enter) on a single machine. You are the "remote clock". Now, how useful that is now adays is open to question, but in the past with telephone modems and flaky connections it was worth something. And if you are setting up something on the Hebrides or on a buoy in the Atlantic where no connection of anykind is possible, it could be useful. Ie, it IS different from orphan mode. > ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 20/02/2015 20:22, William Unruh wrote: [] No. The local clock simply trusts the time (Ie all offsets are defined to be zero) chrony takes the time as entered by hand by the operator and uses that to determine the offset. Of course that will not be terribly accurate ( a second is probably good), but if you are disconnected for a month, a second is probably pretty good accuracy. In practice, how does that differ from orphan mode? I think that statement on behalf of chrony needs to be clarified as it may be misleading. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On Fri, Feb 20, 2015 at 3:23 PM, William Unruh wrote: > ??? how do assume that the chrony docs do not tell the truth? I don't understand that sentence. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP with 2 servers
On 2015-02-20 16:58, William Unruh wrote: On 2015-02-20, Nuno Pereira wrote: In our infrastructure we had some ntp clients that don't have access to the world and so they are configured to use only 2 servers (by the way, the other have 2 more options). In reality both servers are the same, but with different IPs. So you only have one server. Why have two that are the same? From time to time some clients configured in this way lose their reference for some short period. I know how NTP works (http://www.ntp.org/ntpfaq/NTP-s-algo-real.htm#Q-NTP-ALGO), and so this seems to be caused by both 2 servers or just 1 of them not have survived. But both the clients and the servers are physically in the same place, and even if they aren't in the same IP network, they are in the same LAN with just a switch or two between them (delay is between 1 and 2 ms). What is the switch? Smoke signals? Any switch should be a lot lot faster than 1ms. And the question is why this does happen in the local network? Aren't they close enough in order to avoid a split? Given that, I have changed the configuration, and now they only use 1 server, but that is not a good solution. But that is what you have! Any alternative for the configuration? More servers, most likely virtual servers? I dislike the term servers here and prefer sources, as what you need are 3-5 independent sources of time. You can get that by setting up NTP on some other Internet facing physical servers (Windows, Linux, BSD) whose CPUs and network I/O are not overloaded, using pool and/or separate, local, independent sources, and have all your internal clients configured to sync from all of those internal sources. You will have to roll patchings across your internal time sources with delays to ensure that no more than one source is out of sync at any time. -- Take care. Thanks, Brian Inglis ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On Fri, Feb 20, 2015 at 6:21 PM, Harlan Stenn wrote: > This is interesting. It may be that only 4 responses are returned at a > time, but there has been lots of evidence and experience that depending > on your resolver (most resolvers, from what I've seen), you won't get > the same responses each time (this point assumes there are more than 4 > answers to be had). > I suspect the limit of four is enforced by the pool DNS servers and tweaked by a short TTL. Two points: 1) sometimes 2.*.pool is magic. One would want to account for that. 2) sometimes a cache will return the same answer for n.*.pool if n is a constant for longer than you might expect despite the TTL. Something like 0.uk.pool, 1.uk.pool, 3.uk.pool and uk.pool will should return 16 unique IPv4 addresses in the UK. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP with 2 servers
On 2015-02-20, Nuno Pereira wrote: > > > > In our infrastructure we had some ntp clients that don't have access to the > world and so they are configured to use only 2 servers (by the way, the other > have 2 more options). In reality both servers are the same, but with different > IPs. So you only have one server. Why have two that are the same? > > > > From time to time some clients configured in this way lose their reference for > some short period. > > > > I know how NTP works > (http://www.ntp.org/ntpfaq/NTP-s-algo-real.htm#Q-NTP-ALGO), and so this seems > to be caused by both 2 servers or just 1 of them not have survived. > > But both the clients and the servers are physically in the same place, and > even if they aren't in the same IP network, they are in the same LAN with just > a switch or two between them (delay is between 1 and 2 ms). What is the switch? Smoke signals? Any switch should be a lot lot faster than 1ms. > > > > And the question is why this does happen in the local network? > > Aren't they close enough in order to avoid a split? > > > > > > Given that, I have changed the configuration, and now they only use 1 server, > but that is not a good solution. But that is what you have! > > Any alternative for the configuration? More servers, most likely virtual > servers? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On 2015-02-20 12:19, Roger wrote: On 20 Feb 2015 17:49:15 GMT, Rob wrote: Roger wrote: On Fri, 20 Feb 2015 12:45:54 +, Roger wrote: After about 11 minutes it has dropped one, leaving 6 servers. I'll continue to monitor and report back. Just to recap, I now have this in my ntp.conf: pool 0.uk.pool.ntp.org pool 1.uk.pool.ntp.org pool 2.uk.pool.ntp.org pool 3.uk.pool.ntp.org Why not just: pool pool.ntp.org That should be enough. I did have just one line "pool uk.pool.ntp.org" but the rogue server didn't get dropped even after 27 hours. I included the "uk" to try to make sure that the servers were as local as possible. Without that they could be anywhere in Europe. Terje made the suggestion about too few servers. DNS returns 4 IP addresses at a time. By having four lines ntpd could have 12 different IP addresses returned if it used all four lines. As I'm not capable of going through the source code and trying to work out the best strategy I have to do it by trial and error. Add iburst preempt to the ends of your pool server lines to improve startup and drop poorer sources. -- Take care. Thanks, Brian Inglis ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Jan Ceuleers writes: > Using dig on a sample of the pool it seems that DNS queries to the > pool only ever return 4 entries. So if ntpd relies on there being > around 10 servers for some of its monitoring capabilities to kick in > then we seem to have a bit of a disconnect. This is interesting. It may be that only 4 responses are returned at a time, but there has been lots of evidence and experience that depending on your resolver (most resolvers, from what I've seen), you won't get the same responses each time (this point assumes there are more than 4 answers to be had). If the number of answers returned is a local policy choice, then it may well be that one may need multiple pool lines in the ntp.conf file. If "more" answers are returned or if the answers are randomized each time, a single pool line may be all that is required. -- Harlan Stenn http://networktimefoundation.org - be a member! ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On Fri, 20 Feb 2015 20:20:01 +, Phil W Lee wrote: >You may well have mine among them. >I'd appreciate some feedback on how it appears to be performing from >elsewhere. >If 88.96.199.9 looks familiar, drop me an email. No, yours isn't in there at the moment. The Los Angeles monitor shows it wandering around by a some milliseconds. http://www.pool.ntp.org/scores/88.96.199.9 -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] [Is deze mail veilig?] [Is this e-mail safe?] [Cet e-mail est-il sans danger?] Re: Pool server gone wild
On Fri, 20 Feb 2015 19:01:23 GMT, Jan Ceuleers wrote: >On 20/02/15 18:49, Rob wrote: >> Why not just: >> >> pool pool.ntp.org >> >> That should be enough. > >It returns only 2 servers (at the moment, and on my system): There's definitely something wrong; the authority section should be showing ?.ntpns.org. where ? is a - i inclusive. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP with 2 servers
On Fri, Feb 20, 2015 at 3:17 PM, Nuno Pereira wrote: > I know how NTP works > (http://www.ntp.org/ntpfaq/NTP-s-algo-real.htm#Q-NTP-ALGO), and so this > seems > to be caused by both 2 servers or just 1 of them not have survived. > As recently noted the ntpfaq is outdated and shouldn't be used to make design decisions. There's sufficient newer documentation. Your description is too vague to offer good advice but don't add an IP address to a system and then use it like two distinct servers. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On 20 Feb 2015 19:29:44 GMT, Rob wrote: >>>Why not just: >>> >>>pool pool.ntp.org >>> >>>That should be enough. >> >> I did have just one line "pool uk.pool.ntp.org" but the rogue > >Did I write "pool uk.pool.ntp.org"? I don't think so... No, you didn't. Did I say that you did? It is what I had in my ntp.conf. >> server didn't get dropped even after 27 hours. I included the >> "uk" to try to make sure that the servers were as local as >> possible. Without that they could be anywhere in Europe. > >No, the "pool.ntp.org" name selects the closests servers. >Close enough when you consider the pool good enough. Experience tells me that IP addresses are selected on a regional basis, not a country basis. Sometimes they are all in the UK, but not always. For example, earlier today one of the servers that was offered using pool.ntp.org was in Hungary. Putting the country code in makes it more likely that the IP addresses are local. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP with 2 servers
On Feb 20, 2015, at 12:17 PM, Nuno Pereira wrote: > In our infrastructure we had some ntp clients that don't have access to the > world and so they are configured to use only 2 servers (by the way, the other > have 2 more options). In reality both servers are the same, but with different > IPs. I think ntpd would see the same reference id for that timesource regardless of which IP you reach it by, and loop detection would figure it out. [ ... ] > Given that, I have changed the configuration, and now they only use 1 server, > but that is not a good solution. Using 1 server is better than using 2. Using at least 4 servers is better than using 1. > Any alternative for the configuration? More servers, most likely virtual > servers? VMs make anywhere from terrible to adequate timeservers. Bare metal or at the hypervisor level is preferable. Setup a local NTP subnet of at least 4 peers, and have your clients talk to each of those. Your chosen ntp servers should each be configured with at least one unique timesource which is not used by anything else to promote diversity. Regards, -- -Chuck ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On 2015-02-20, Roger wrote: > http://www.pool.ntp.org/scores/90.155.73.34 > > How does one alert an operator that their server is sick? > Checking back through my peerstats I see that last entry > which was okay was 2015-02-16 15:08:56. Send them an email? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-19, Paul wrote: > On Thu, Feb 19, 2015 at 5:34 AM, David Taylor < > david-tay...@blueyonder.co.uk.invalid> wrote: > >> Does not NTP's orphan mode and local clock driver provide this? > > > Refclock 1 (LOCAL/LOCL) is deprecated and I believe as of a recent release > it's useless* but "Orphan mode is intended to replace the local clock > driver. It provides a single simulated UTC source ...". Note that I > provided a link not any commentary on the correctness of the claims at that > link. It would be nice if the Chrony docs told the truth but likewise the > NTP docs. ??? how do assume that the chrony docs do not tell the truth? > > *Previously LOCL+PPS was a useful configuration, now you need (or should) > use kernel PPS. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-19, Rob wrote: > Miroslav Lichvar wrote: >> My update to that after the years would be that 3x is not really the >> minimum difference. If the clock is stable enough, they can perform >> similarly. > > Indeed when a system is in a reasonably constant temperature and the > clock happens to be good, ntpd performs similar to chrony. As I said, I believe that one of the reasons chrony is better is because it reacts to changes, like temp change, much faster. If there are no changes, I suspect, but cannot prove, that they are very similar. But most people do not have temperature controlled crystals on their computer, and most people have variable work that their computer does, so the internal temperature fluctuates. > > We have systems in places that are not temperature controlled and then > chrony is much better. I am looking for the best way to find the > values to use in the tempcomp configuration directive. > > Ideally there would be a program that analyzes a log of momentary > temperature and frequency values to find the coefficients, but how > is such a logfile even generated? > > Should I enter a tempcomp line with zero coefficients and then use > the tempcomp logging? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-19, David Taylor wrote: > On 19/02/2015 01:24, Paul wrote: > [] >> Chrony (in general) pros and cons: < >> http://chrony.tuxfamily.org/manual.html#Other-time-synchronisation-packages> > [] > > ... whwre it says: "Things chronyd can do that ntpd can?t: chronyd > provides support for isolated networks whether the only method of time > correction is manual entry (e.g. by the administrator looking at a clock)." > > Does not NTP's orphan mode and local clock driver provide this? > No. The local clock simply trusts the time (Ie all offsets are defined to be zero) chrony takes the time as entered by hand by the operator and uses that to determine the offset. Of course that will not be terribly accurate ( a second is probably good), but if you are disconnected for a month, a second is probably pretty good accuracy. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-19, Rob wrote: > Miroslav Lichvar wrote: >> On Thu, Feb 19, 2015 at 10:05:45AM +, Rob wrote: >>> We have systems in places that are not temperature controlled and then >>> chrony is much better. I am looking for the best way to find the >>> values to use in the tempcomp configuration directive. >> >> What resolution does the sensor have? Don't expect good results >> with 1C or 0.5C resolution that sensors on mainboards typically have. > > I am still finding out what sensor is best to use, we do have a room > temperature sensor that has .1C resolution and is readable via snmp, > and there are the usual sensors for board- and inlet air temperature. > (and of course CPU temperature) > > It does not matter if it is only a course indication, the room temperature > varies over a -10 .. 50C range (don't ask...) and a 1C resolution is not > bad relative to that. It is of course the temperature of the crystal itself that is important. Ie, the room temp could be constant and the computer varies in its workload and thus its internal temperature. Unfortunately temp sensors on the crystal are rare in commodity computers. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On 2015-02-19, Rob wrote: > Miroslav Lichvar wrote: >> On Thu, Feb 19, 2015 at 12:48:46PM +, Rob wrote: >>> I am still finding out what sensor is best to use, we do have a room >>> temperature sensor that has .1C resolution and is readable via snmp, >>> and there are the usual sensors for board- and inlet air temperature. >>> (and of course CPU temperature) >>> >>> It does not matter if it is only a course indication, the room temperature >>> varies over a -10 .. 50C range (don't ask...) and a 1C resolution is not >>> bad relative to that. >> >> In my tests using a sensor with 1C resolution it was barely useful >> with NTP sources and 1024s polling interval. If the sensitivity is >> around 0.1 ppm per degree, 1C resolution means the compensation >> jumping the frequency in 0.1ppm steps. That's a lot, especially if you >> compare it to the tracking skew with a refclock. > > Ok but of course we are using PPS and a 16 second polling interval. > (or maybe the PPS refclock polls even faster although it displays 4 as > the poll interval indicator) The shm refclock will get one pulse per second, and then average the offsets over a 16 sec period after getting rid of the outliers. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] NTP with 2 servers
Hello. In our infrastructure we had some ntp clients that don't have access to the world and so they are configured to use only 2 servers (by the way, the other have 2 more options). In reality both servers are the same, but with different IPs. >From time to time some clients configured in this way lose their reference for some short period. I know how NTP works (http://www.ntp.org/ntpfaq/NTP-s-algo-real.htm#Q-NTP-ALGO), and so this seems to be caused by both 2 servers or just 1 of them not have survived. But both the clients and the servers are physically in the same place, and even if they aren't in the same IP network, they are in the same LAN with just a switch or two between them (delay is between 1 and 2 ms). And the question is why this does happen in the local network? Aren't they close enough in order to avoid a split? Given that, I have changed the configuration, and now they only use 1 server, but that is not a good solution. Any alternative for the configuration? More servers, most likely virtual servers? Thank you. Nuno Pereira G9Telecom ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Roger wrote: > On 20 Feb 2015 17:49:15 GMT, Rob wrote: > >>Roger wrote: >>> On Fri, 20 Feb 2015 12:45:54 +, Roger >>> wrote: >>> After about 11 minutes it has dropped one, leaving 6 servers. I'll continue to monitor and report back. >>> >>> Just to recap, I now have this in my ntp.conf: >>> >>> pool 0.uk.pool.ntp.org >>> pool 1.uk.pool.ntp.org >>> pool 2.uk.pool.ntp.org >>> pool 3.uk.pool.ntp.org >> >>Why not just: >> >>pool pool.ntp.org >> >>That should be enough. > > I did have just one line "pool uk.pool.ntp.org" but the rogue Did I write "pool uk.pool.ntp.org"? I don't think so... > server didn't get dropped even after 27 hours. I included the > "uk" to try to make sure that the servers were as local as > possible. Without that they could be anywhere in Europe. No, the "pool.ntp.org" name selects the closests servers. Close enough when you consider the pool good enough. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On 20 Feb 2015 17:49:15 GMT, Rob wrote: >Roger wrote: >> On Fri, 20 Feb 2015 12:45:54 +, Roger >> wrote: >> >>>After about 11 minutes it has dropped one, leaving 6 servers. >>>I'll continue to monitor and report back. >> >> Just to recap, I now have this in my ntp.conf: >> >> pool 0.uk.pool.ntp.org >> pool 1.uk.pool.ntp.org >> pool 2.uk.pool.ntp.org >> pool 3.uk.pool.ntp.org > >Why not just: > >pool pool.ntp.org > >That should be enough. I did have just one line "pool uk.pool.ntp.org" but the rogue server didn't get dropped even after 27 hours. I included the "uk" to try to make sure that the servers were as local as possible. Without that they could be anywhere in Europe. Terje made the suggestion about too few servers. DNS returns 4 IP addresses at a time. By having four lines ntpd could have 12 different IP addresses returned if it used all four lines. As I'm not capable of going through the source code and trying to work out the best strategy I have to do it by trial and error. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On Feb 20, 2015, at 10:55 AM, Jan Ceuleers wrote: > Using dig on a sample of the pool it seems that DNS queries to the pool > only ever return 4 entries. Per request, yes-- with something like a 150 or 300 second TTL. Hopefully, you get a different set of hosts returned from: dig 0.uk.pool.ntp.org ..vs.. dig 1.uk.pool.ntp.org > So if ntpd relies on there being around 10 servers for some of its monitoring > capabilities to kick in then we seem to have a bit of a disconnect. ntpd wants to have at least 4 servers around for falseticker detection. Using the pool directive should encourage it to get at least 5 - 6 sources, but you might have to wait some time before it re-queries for new servers if you only listed a single pool directive. Regards, -- -Chuck ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] [Is deze mail veilig?] [Is this e-mail safe?] [Cet e-mail est-il sans danger?] Re: Pool server gone wild
On 20/02/15 18:49, Rob wrote: > Why not just: > > pool pool.ntp.org > > That should be enough. It returns only 2 servers (at the moment, and on my system): root@hobbiton:~# dig pool.ntp.org ; <<>> DiG 9.9.5-3ubuntu0.2-Ubuntu <<>> pool.ntp.org ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7739 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 13, ADDITIONAL: 25 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;pool.ntp.org. IN A ;; ANSWER SECTION: pool.ntp.org. 146 IN A 85.201.95.107 pool.ntp.org. 146 IN A 213.189.188.3 ;; AUTHORITY SECTION: . 36537 IN NS f.root-servers.net. . 36537 IN NS b.root-servers.net. . 36537 IN NS j.root-servers.net. . 36537 IN NS h.root-servers.net. . 36537 IN NS m.root-servers.net. . 36537 IN NS c.root-servers.net. . 36537 IN NS k.root-servers.net. . 36537 IN NS d.root-servers.net. . 36537 IN NS g.root-servers.net. . 36537 IN NS a.root-servers.net. . 36537 IN NS l.root-servers.net. . 36537 IN NS i.root-servers.net. . 36537 IN NS e.root-servers.net. ;; ADDITIONAL SECTION: a.root-servers.net. 300936 IN A 198.41.0.4 a.root-servers.net. 301233 IN 2001:503:ba3e::2:30 b.root-servers.net. 300942 IN A 192.228.79.201 b.root-servers.net. 317560 IN 2001:500:84::b c.root-servers.net. 300974 IN A 192.33.4.12 c.root-servers.net. 304383 IN 2001:500:2::c d.root-servers.net. 110366 IN A 199.7.91.13 d.root-servers.net. 121013 IN 2001:500:2d::d e.root-servers.net. 112934 IN A 192.203.230.10 f.root-servers.net. 101758 IN A 192.5.5.241 f.root-servers.net. 107135 IN 2001:500:2f::f g.root-servers.net. 110990 IN A 192.112.36.4 h.root-servers.net. 11 IN A 128.63.2.53 h.root-servers.net. 116217 IN 2001:500:1::803f:235 i.root-servers.net. 110930 IN A 192.36.148.17 i.root-servers.net. 114101 IN 2001:7fe::53 j.root-servers.net. 111931 IN A 192.58.128.30 j.root-servers.net. 118767 IN 2001:503:c27::2:30 k.root-servers.net. 112005 IN A 193.0.14.129 k.root-servers.net. 8040IN 2001:7fd::1 l.root-servers.net. 111937 IN A 199.7.83.42 l.root-servers.net. 113806 IN 2001:500:3::42 m.root-servers.net. 300975 IN A 202.12.27.33 m.root-servers.net. 302827 IN 2001:dc3::35 ;; Query time: 36 msec ;; SERVER: 127.0.1.1#53(127.0.1.1) ;; WHEN: Fri Feb 20 19:57:58 CET 2015 ;; MSG SIZE rcvd: 800 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On 20/02/15 18:46, Roger wrote: > On Fri, 20 Feb 2015 12:45:54 +, Roger > wrote: > >> After about 11 minutes it has dropped one, leaving 6 servers. >> I'll continue to monitor and report back. > > Just to recap, I now have this in my ntp.conf: > > pool 0.uk.pool.ntp.org > pool 1.uk.pool.ntp.org > pool 2.uk.pool.ntp.org > pool 3.uk.pool.ntp.org > > After five hours ntpd is using the same 6 servers. Perhaps > because all of the peerstats have been less than 3 milli- > seconds ntpd is quite happy even though the reach of one of > the servers isn't always 377. Using dig on a sample of the pool it seems that DNS queries to the pool only ever return 4 entries. So if ntpd relies on there being around 10 servers for some of its monitoring capabilities to kick in then we seem to have a bit of a disconnect. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Roger wrote: > On Fri, 20 Feb 2015 12:45:54 +, Roger > wrote: > >>After about 11 minutes it has dropped one, leaving 6 servers. >>I'll continue to monitor and report back. > > Just to recap, I now have this in my ntp.conf: > > pool 0.uk.pool.ntp.org > pool 1.uk.pool.ntp.org > pool 2.uk.pool.ntp.org > pool 3.uk.pool.ntp.org Why not just: pool pool.ntp.org That should be enough. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On Fri, 20 Feb 2015 12:45:54 +, Roger wrote: >After about 11 minutes it has dropped one, leaving 6 servers. >I'll continue to monitor and report back. Just to recap, I now have this in my ntp.conf: pool 0.uk.pool.ntp.org pool 1.uk.pool.ntp.org pool 2.uk.pool.ntp.org pool 3.uk.pool.ntp.org After five hours ntpd is using the same 6 servers. Perhaps because all of the peerstats have been less than 3 milli- seconds ntpd is quite happy even though the reach of one of the servers isn't always 377. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Mike Cook wrote: < snipped> The server was still in the peerstats at 18:25 the following day when I did a reboot. So, after approximately 27 hours, ntpd hadn't dropped it. Obviously, my system isn't performing as you say it should. Can you, or anyone else, provide a clue as to how I might determine if my system is a fault or if there is a bug in the ntpd code? I.e. as long as you use the pool properly there is no need to worry about servers coming and going, or even individual servers that become falsetickers. Hmmm. Sometime back I had noticed on my servers using the pool, that a couple of the selected servers had stopped responding. I did not know at the time that that situation was supposed to be dynamically corrected so I dropped the pool as being unreliable. Maybe there is some issue. I just re-configured 4 servers back to using the pool and will monitor for black sheep. You have to use the 'pool' instead of 'server' command in order to get the automatic inclusion of multiple servers, with automatic monitoring and pruning. When I first tried 4.2.8 I noticed the "soliciting" lines and that occasionally a server didn't get used. I have that too. Could this also be because you don't have enough servers in your pool? Terje -- - "almost all programming can be viewed as an exercise in caching" ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
< snipped> > > The server was still in the peerstats at 18:25 the following day > when I did a reboot. So, after approximately 27 hours, ntpd > hadn't dropped it. Obviously, my system isn't performing as you > say it should. Can you, or anyone else, provide a clue as to how > I might determine if my system is a fault or if there is a bug > in the ntpd code? > >> I.e. as long as you use the pool properly there is no need to worry >> about servers coming and going, or even individual servers that become >> falsetickers. Hmmm. Sometime back I had noticed on my servers using the pool, that a couple of the selected servers had stopped responding. I did not know at the time that that situation was supposed to be dynamically corrected so I dropped the pool as being unreliable. Maybe there is some issue. I just re-configured 4 servers back to using the pool and will monitor for black sheep. > > When I first tried 4.2.8 I noticed the "soliciting" lines and > that occasionally a server didn't get used. I have that too. Feb 20 13:49:42 raspB2 ntpd[27451]: Soliciting pool server 195.154.41.195 Feb 20 13:50:48 raspB2 ntpd[27451]: Soliciting pool server 195.154.216.35 Feb 20 13:51:55 raspB2 ntpd[27451]: Soliciting pool server 5.39.78.25 Feb 20 13:51:56 raspB2 ntpd[27451]: Soliciting pool server 91.121.157.10 Feb 20 13:53:05 raspB2 ntpd[27451]: Soliciting pool server 195.154.78.115 Feb 20 13:54:12 raspB2 ntpd[27451]: Soliciting pool server 212.83.131.33 ^Cmike@raspB2 ~ ntpq -pn remote refid st t when poll reach delay offset jitter == *127.127.28.1.GPS2. 0 l4 16 3770.0000.008 0.006 +192.168.1.4 .PPS1. 1 u3 16 3770.9260.039 0.032 +192.168.1.23.GPS.1 u2 16 3770.5830.049 0.218 0.pool.ntp.org .POOL. 16 p- 6400.0000.000 0.004 +5.39.78.25 140.7.62.122 2 u 14 64 175.8832.928 0.047 +188.165.255.179 193.110.137.171 2 u2 6416.0790.342 0.057 It also seems to be soliciting every minute and 7 secs. rather than hourly. Feb 20 13:49:42 raspB2 ntpd[27451]: Soliciting pool server 195.154.41.195 Feb 20 13:50:48 raspB2 ntpd[27451]: Soliciting pool server 195.154.216.35 Feb 20 13:51:55 raspB2 ntpd[27451]: Soliciting pool server 5.39.78.25 Feb 20 13:51:56 raspB2 ntpd[27451]: Soliciting pool server 91.121.157.10 Feb 20 13:53:05 raspB2 ntpd[27451]: Soliciting pool server 195.154.78.115 Feb 20 13:54:12 raspB2 ntpd[27451]: Soliciting pool server 212.83.131.33 Feb 20 13:55:18 raspB2 ntpd[27451]: Soliciting pool server 188.165.255.179 Feb 20 13:55:19 raspB2 ntpd[27451]: Soliciting pool server 91.121.167.51 Feb 20 13:56:28 raspB2 ntpd[27451]: Soliciting pool server 178.32.54.53 Feb 20 13:57:35 raspB2 ntpd[27451]: Soliciting pool server 91.121.165.146 Feb 20 13:58:42 raspB2 ntpd[27451]: Soliciting pool server 91.121.169.20 Feb 20 13:59:50 raspB2 ntpd[27451]: Soliciting pool server 37.187.107.140 Feb 20 14:00:58 raspB2 ntpd[27451]: Soliciting pool server 195.154.108.164 Feb 20 14:02:05 raspB2 ntpd[27451]: Soliciting pool server 178.32.54.53 Feb 20 14:03:13 raspB2 ntpd[27451]: Soliciting pool server 129.250.35.250 Feb 20 14:04:22 raspB2 ntpd[27451]: Soliciting pool server 5.39.71.117 Feb 20 14:05:31 raspB2 ntpd[27451]: Soliciting pool server 129.250.35.251 Feb 20 14:06:38 raspB2 ntpd[27451]: Soliciting pool server 37.187.2.84 Feb 20 14:07:45 raspB2 ntpd[27451]: Soliciting pool server 87.98.188.218 > ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On Fri, 20 Feb 2015 12:38:50 +0100, Terje Mathisen wrote: >Roger wrote: >> On Fri, 20 Feb 2015 10:15:31 +0100, Terje Mathisen >> wrote: >> >>> Rob wrote: Roger wrote: > http://www.pool.ntp.org/scores/90.155.73.34 > > How does one alert an operator that their server is sick? > Checking back through my peerstats I see that last entry > which was okay was 2015-02-16 15:08:56. There is no need. The pool system has sent a mail to the operator and when he apparently does not react it is not a problem because the server will have been removed from the pool anyway. >>> You are of course correct, I would just add a single small caveat: >> >> OK, Rob, thanks for that. >> >>> If you are using an older version of ntpd which doesn't support the pool >>> directive, then you would be stuck trying to access such a server until >>> you restart ntpd. >>> >>> With something like 'pool pool.ntp.org' in your ntp.conf file the ntpd >>> process will pick the first N (10) servers returned from DNS, then once >>> every hour it will redo the DNS lookp, the two worst-performing current >>> servers will be removed and a pair of new ones will be used to replace them. >> >> I'm using 4.2.8p1 (compiled using gcc 4.8.2 and binutils 2.23, >> if those are important) and "pool uk.pool.ntp.org" as the only >> selection line. > >The UK pool might have too few servers. > >What does your 'ntpq -p' look like? > >If you have less than 10 servers then none of them will be dropped >afair, but you can tweak this limit with a fudge command. Thank you for your fast response. A dig of uk.pool.ntp.org gives 4 addresses. I've changed my ntp.conf to have 4 pool lines selecting 0.uk, 1.uk, 2.uk, and 3.uk (each of these gives 4 addresses, presumably all different). Restarting ntpd it solicited 7 servers all of which show up with "ntpq -p" (along with the four pool lines). After about 11 minutes it has dropped one, leaving 6 servers. I'll continue to monitor and report back. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On Fri, 20 Feb 2015 10:15:31 +0100, Terje Mathisen wrote: >Rob wrote: >> Roger wrote: >>> http://www.pool.ntp.org/scores/90.155.73.34 >>> >>> How does one alert an operator that their server is sick? >>> Checking back through my peerstats I see that last entry >>> which was okay was 2015-02-16 15:08:56. >> >> There is no need. The pool system has sent a mail to the operator >> and when he apparently does not react it is not a problem because >> the server will have been removed from the pool anyway. >> >You are of course correct, I would just add a single small caveat: OK, Rob, thanks for that. >If you are using an older version of ntpd which doesn't support the pool >directive, then you would be stuck trying to access such a server until >you restart ntpd. > >With something like 'pool pool.ntp.org' in your ntp.conf file the ntpd >process will pick the first N (10) servers returned from DNS, then once >every hour it will redo the DNS lookp, the two worst-performing current >servers will be removed and a pair of new ones will be used to replace them. I'm using 4.2.8p1 (compiled using gcc 4.8.2 and binutils 2.23, if those are important) and "pool uk.pool.ntp.org" as the only selection line. The server was still in the peerstats at 18:25 the following day when I did a reboot. So, after approximately 27 hours, ntpd hadn't dropped it. Obviously, my system isn't performing as you say it should. Can you, or anyone else, provide a clue as to how I might determine if my system is a fault or if there is a bug in the ntpd code? >I.e. as long as you use the pool properly there is no need to worry >about servers coming and going, or even individual servers that become >falsetickers. When I first tried 4.2.8 I noticed the "soliciting" lines and that occasionally a server didn't get used. I've never noticed ntpd dropping a server once it had started using it but this is the first time that a server has been so obviously wrong that I would have wanted it dropped/replaced. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Roger wrote: On Fri, 20 Feb 2015 10:15:31 +0100, Terje Mathisen wrote: Rob wrote: Roger wrote: http://www.pool.ntp.org/scores/90.155.73.34 How does one alert an operator that their server is sick? Checking back through my peerstats I see that last entry which was okay was 2015-02-16 15:08:56. There is no need. The pool system has sent a mail to the operator and when he apparently does not react it is not a problem because the server will have been removed from the pool anyway. You are of course correct, I would just add a single small caveat: OK, Rob, thanks for that. If you are using an older version of ntpd which doesn't support the pool directive, then you would be stuck trying to access such a server until you restart ntpd. With something like 'pool pool.ntp.org' in your ntp.conf file the ntpd process will pick the first N (10) servers returned from DNS, then once every hour it will redo the DNS lookp, the two worst-performing current servers will be removed and a pair of new ones will be used to replace them. I'm using 4.2.8p1 (compiled using gcc 4.8.2 and binutils 2.23, if those are important) and "pool uk.pool.ntp.org" as the only selection line. The UK pool might have too few servers. What does your 'ntpq -p' look like? If you have less than 10 servers then none of them will be dropped afair, but you can tweak this limit with a fudge command. Terje The server was still in the peerstats at 18:25 the following day when I did a reboot. So, after approximately 27 hours, ntpd hadn't dropped it. Obviously, my system isn't performing as you say it should. Can you, or anyone else, provide a clue as to how I might determine if my system is a fault or if there is a bug in the ntpd code? I.e. as long as you use the pool properly there is no need to worry about servers coming and going, or even individual servers that become falsetickers. When I first tried 4.2.8 I noticed the "soliciting" lines and that occasionally a server didn't get used. I've never noticed ntpd dropping a server once it had started using it but this is the first time that a server has been so obviously wrong that I would have wanted it dropped/replaced. -- - "almost all programming can be viewed as an exercise in caching" ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
On 20/02/15 08:45, Roger wrote: http://www.pool.ntp.org/scores/90.155.73.34 How does one alert an operator that their server is sick? Checking back through my peerstats I see that last entry which was okay was 2015-02-16 15:08:56. You could run whois on the address and contact the contact address given. It is a small ISP (AAISP), so there is a good chance that the message will get through. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On Thu, Feb 19, 2015 at 10:58:14PM +, Harlan Stenn wrote: > Would the temperature monitoring script and coefficient > generation/processsing stuff be a good GSoC project? Not really, it would be probably easier to write the scripts than write the GSoC application. I'd be more interested in some research on software temperature compensation itself, how good the measurements need to be for a given time reference to be useful etc. -- Miroslav Lichvar ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] chrony as a server
On Thu, Feb 19, 2015 at 04:15:45PM +, Rob wrote: > > The default PPS refclock driver poll is 0 (1s), this be changed too > > if the PPS signal has a higher rate. Some GPS units seems to have this > > configurable (e.g. ublox NEO-6T). > > The PPS really is 1 PPS, but I am not sure if chrony is evaluating each > pulse separately or is averaging 16 pulse measurements into one clock > adjustment group. (as it says poll 4) It's the latter. The PPS samples collected in one poll interval are processed by a median filter and the result is used to update the source statistics and update the clock. -- Miroslav Lichvar ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Rob wrote: Roger wrote: http://www.pool.ntp.org/scores/90.155.73.34 How does one alert an operator that their server is sick? Checking back through my peerstats I see that last entry which was okay was 2015-02-16 15:08:56. There is no need. The pool system has sent a mail to the operator and when he apparently does not react it is not a problem because the server will have been removed from the pool anyway. You are of course correct, I would just add a single small caveat: If you are using an older version of ntpd which doesn't support the pool directive, then you would be stuck trying to access such a server until you restart ntpd. With something like 'pool pool.ntp.org' in your ntp.conf file the ntpd process will pick the first N (10) servers returned from DNS, then once every hour it will redo the DNS lookp, the two worst-performing current servers will be removed and a pair of new ones will be used to replace them. I.e. as long as you use the pool properly there is no need to worry about servers coming and going, or even individual servers that become falsetickers. Terje -- - "almost all programming can be viewed as an exercise in caching" ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] Pool server gone wild
http://www.pool.ntp.org/scores/90.155.73.34 How does one alert an operator that their server is sick? Checking back through my peerstats I see that last entry which was okay was 2015-02-16 15:08:56. -- Roger ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool server gone wild
Roger wrote: > http://www.pool.ntp.org/scores/90.155.73.34 > > How does one alert an operator that their server is sick? > Checking back through my peerstats I see that last entry > which was okay was 2015-02-16 15:08:56. There is no need. The pool system has sent a mail to the operator and when he apparently does not react it is not a problem because the server will have been removed from the pool anyway. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
