Re: [ntp:questions] Attn Linux distributors - pse include PPS
Harlan Stenn st...@ntp.org wrote: William Unruh writes: On 2014-04-25, Paul tik-...@bodosom.net wrote: On Fri, Apr 25, 2014 at 4:36 PM, William Unruh un...@invalid.ca wrote: Why shoul dit ship with no refclocks? ... DO you have the same opinion for serial port or parallel ports, or network drivers? (Ignoring your mischaracterization of what I said and the strawman arguments) because a negligible number of time consumers have a refclock. Back in the day I recall a distro that had ntp-client and ntp-server packages -- so I'm sure I'm not the first person to propose it. More recent ntpd combine server and client in one program. Not sure when that was. It's been the case for at least 20 years' time. This is something that may be different in the upcoming rewrite. I think it is not a wrong guess that there are more systems that use ntp only over the network than there are systems which have local refclocks as well. But that is not the point. The point is that the program is compiled with a fixed set of refclocks that is unneccessarily limited because the environment it was compiled in was not complete. This would be less of a problem when the refclocks were loadable modules or were running in separate processes on the same machine. Then one could compile a single refclock module or program and add it to an existing system. But until that has been implemented, we could at least try to have the distributors build a complete ntpd by default. Today there is no reason (on the PC platform at least) to squeeze out a few KB of the executable size by omitting a couple of refclocks. My custom built ntpd on Ubuntu is just 55216 bytes larger than the default one. Those bytes probably don't even occupy memory. But it took me 2 hours to learn how to build it and actually do that, a waste of time IMHO. And it is now in risk of being overwritten by a security update. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] ntpd as a client when port 123 blocked
On a Linux system we ran into the problem that port 123 has been blocked for incoming traffic (probably as a general countermeasure against abuse of badly configured servers, this server was configured correctly). As it is not possible to change the source port number in ntpd, I translated the source port using a nat rule: iptables -t nat -A POSTROUTING -p udp --sport 123 -j SNAT --to-source :12300 Now it again works fine. Of course it cannot be used as a server by outside clients, but that was not the objective anyway. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Fri, Apr 25, 2014 at 11:18 PM, William Unruh un...@invalid.ca wrote: As do you-- generalising from your one situation. Are you actually suggesting that the number of refclocks is a non-negligible fraction of the number of clients? Even if you only include Linux that makes no sense. Most of our non-mobile clients run windows and get time from Microsoft or the domain which gets it from our S2 servers. Most of our Linux instances are servers which get time from our S2 servers. I don't imagine our circustances are wildly out of line. By the way comparing network kernel drivers to application build choices is silly. I'm willing to firmly assert that there's much greater need for network support than there is for the ATOM refclock. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Sat, Apr 26, 2014 at 3:33 AM, Rob nom...@example.com wrote: The point is that the program is compiled with a fixed set of refclocks that is unneccessarily limited because the environment it was compiled in was not complete. Are you saying that the ntpd that ships with Ubuntu 14.04 is limited or are you referring to your build here? The latter seems odd but since you don't know what was in the upstream build environment the former also seems odd. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Paul tik-...@bodosom.net wrote: On Sat, Apr 26, 2014 at 3:33 AM, Rob nom...@example.com wrote: The point is that the program is compiled with a fixed set of refclocks that is unneccessarily limited because the environment it was compiled in was not complete. Are you saying that the ntpd that ships with Ubuntu 14.04 is limited or are you referring to your build here? The latter seems odd but since you don't know what was in the upstream build environment the former also seems odd. I am saying that the ntpd that ships with Ubuntu 14.04 is limited because it was built on a system where timepps.h was not present, and thus the ATOM and JUPITER (and a couple other) refclocks were not included in the binary. Even though PPS support is present in the kernel. I built ntpd locally after installing the package pps-tools, which includes timepps.h, and then everything is OK. ./configure detects the presence of timepps.h and then enables all refclocks with PPS support. But I would prefer not having to build ntpd to get the ATOM refclock working. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
I am saying that the ntpd that ships with Ubuntu 14.04 is limited because it was built on a system where timepps.h was not present, and thus the ATOM and JUPITER (and a couple other) refclocks were not included in the binary. Even though PPS support is present in the kernel. I built ntpd locally after installing the package pps-tools, which includes timepps.h, and then everything is OK. ./configure detects the presence of timepps.h and then enables all refclocks with PPS support. But I would prefer not having to build ntpd to get the ATOM refclock working. Don't you think that is a gripe for the people over at Ubuntu? Developers have no control how others choose to implement their software. Hence the discussion here is about as pointless as complaining on the Microsoft support forum about how Apple does something in their UI and should change it... *facepalm* ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Sat, Apr 26, 2014 at 4:34 PM, Jason Rabel ja...@extremeoverclocking.comwrote: Don't you think that is a gripe for the people over at Ubuntu? Well maybe. The OP was directed to Linux distributors but in this case that's Debian not Ubuntu. But to your point -- even if you don't much care for my comprehensive approach -- get current sources and build what you need -- I think it's fair to wonder why the NTP tar ball doesn't include timepps-Linux.h along with others they do include. So wrong subject line but right mailing list. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Jason Rabel ja...@extremeoverclocking.com wrote: I am saying that the ntpd that ships with Ubuntu 14.04 is limited because it was built on a system where timepps.h was not present, and thus the ATOM and JUPITER (and a couple other) refclocks were not included in the binary. Even though PPS support is present in the kernel. I built ntpd locally after installing the package pps-tools, which includes timepps.h, and then everything is OK. ./configure detects the presence of timepps.h and then enables all refclocks with PPS support. But I would prefer not having to build ntpd to get the ATOM refclock working. Don't you think that is a gripe for the people over at Ubuntu? Developers have no control how others choose to implement their software. Hence the discussion here is about as pointless as complaining on the Microsoft support forum about how Apple does something in their UI and should change it... *facepalm* It is about how they configure their build machines. You know, the place where the source packages are loaded on a computer, compiled, and binary packages are being produced to fill a DVD or website. If that is outside the control of the people at Ubuntu, I have misunderstood the place of Ubuntu in the distributor landscape. Is the Ubuntu distribution being built by the people at Debian? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On 2014-04-26, Jason Rabel ja...@extremeoverclocking.com wrote: I am saying that the ntpd that ships with Ubuntu 14.04 is limited because it was built on a system where timepps.h was not present, and thus the ATOM and JUPITER (and a couple other) refclocks were not included in the binary. Even though PPS support is present in the kernel. I built ntpd locally after installing the package pps-tools, which includes timepps.h, and then everything is OK. ./configure detects the presence of timepps.h and then enables all refclocks with PPS support. But I would prefer not having to build ntpd to get the ATOM refclock working. Don't you think that is a gripe for the people over at Ubuntu? Developers have no control how others choose to implement their software. Hence the discussion here is about as pointless as complaining on the Microsoft support forum about how Apple does something in their UI and should change it... *facepalm* Well, ntpd could include timepps.h into ntpd source and point to it, instead of using the system one. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
William Unruh un...@invalid.ca wrote: On 2014-04-26, Jason Rabel ja...@extremeoverclocking.com wrote: I am saying that the ntpd that ships with Ubuntu 14.04 is limited because it was built on a system where timepps.h was not present, and thus the ATOM and JUPITER (and a couple other) refclocks were not included in the binary. Even though PPS support is present in the kernel. I built ntpd locally after installing the package pps-tools, which includes timepps.h, and then everything is OK. ./configure detects the presence of timepps.h and then enables all refclocks with PPS support. But I would prefer not having to build ntpd to get the ATOM refclock working. Don't you think that is a gripe for the people over at Ubuntu? Developers have no control how others choose to implement their software. Hence the discussion here is about as pointless as complaining on the Microsoft support forum about how Apple does something in their UI and should change it... *facepalm* Well, ntpd could include timepps.h into ntpd source and point to it, instead of using the system one. Apparently there is unresolved discussion whether a .h describing a PPS API belongs in the set of kernel include files or in a separate package. But the separate package pps-tools which includes this file already exists. The only problem is that this package is not installed on the build machines. I don't understand why this is a problem that can be fixed in a minute. There must be TENS of packages that have to be installed on the build machine to successfully build the binaries in the distribution. Compilers, linkers, packaging tools, libraries, etc etc etc. Can't they add just one simple package to that? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
On Fri, Apr 25, 2014 at 11:22 PM, William Unruh un...@invalid.ca wrote: I have 8 machines that reliably sync from one GPS PPS driven machine (all using chrony) and they get time reliability of about 10microseconds How do you determine the 10 micosec. value? And why are you conflating NTP performance with Chrony performance? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Sat, Apr 26, 2014 at 6:30 PM, Rob nom...@example.com wrote: Can't they add just one simple package to that? Well pps-tools is clearly special. E.g. it's no longer advertised for 12.04 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
William Unruh writes: Well, ntpd could include timepps.h into ntpd source and point to it, instead of using the system one. Is there only one version of that file that is compatible with the places NTP will be built? What sort of bit-rot issues are there if we include a copy of the file in the NTP distribution? And even if so, why should this issue cost-shift to the NTP Project? H ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
On 2014-04-26, Paul tik-...@bodosom.net wrote: On Fri, Apr 25, 2014 at 11:22 PM, William Unruh un...@invalid.ca wrote: I have 8 machines that reliably sync from one GPS PPS driven machine (all using chrony) and they get time reliability of about 10microseconds How do you determine the 10 micosec. value? Two ways. One is to simply use the offset scatter as an estimate of the time performace (It is at least some sort of upper bound, but as I have said, not terribly accurate) and secondly by hooking a GS PPS to the machine and looking at the offsets on that. And why are you conflating NTP performance with Chrony performance? BEcause they are comparable ( chrony is somthing like 2-3 times better than ntpd, but not 1000 times better). They both use ntp packet exchange to exchange time. ntpd uses a (slow) very simply feedback loop, chrony uses a linear regression, but again the two are comparable. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
On Sat, Apr 26, 2014 at 8:30 PM, William Unruh un...@invalid.ca wrote: use the offset scatter as an estimate of the time performace (It is at least some sort of upper bound, but as I have said, not terribly accurate) I suspect you shouting CANNOT is probably overstating the issue. After all if offset was of no value how would NTP (or any other offset based time transfer system) work? To the previous point -- if someone says my offsets are always 10s of microseconds that is likely to be a refutation of the 'NTP can't do better than 10s of milliseconds position. I don't know what terribly accurate might be to you but in the real world sufficient accuracy depends on the circumstance. Someone should conduct an experiment. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
On 2014-04-27, Paul tik-...@bodosom.net wrote: On Sat, Apr 26, 2014 at 8:30 PM, William Unruh un...@invalid.ca wrote: use the offset scatter as an estimate of the time performace (It is at least some sort of upper bound, but as I have said, not terribly accurate) I suspect you shouting CANNOT is probably overstating the issue. After all if offset was of no value how would NTP (or any other offset based time transfer system) work? To get a good idea of the actual offset from UTC, you need another time source (or two) to compare with each other. The straight offsets do not give it to you. However, I will admit that they are probably an upper bound (although even that is not true-- the link could have assymetric offsets.) To the previous point -- if someone says my offsets are always 10s of microseconds that is likely to be a refutation of the 'NTP can't do better than 10s of milliseconds position. agreed. I don't know what terribly accurate might be to you but in the real world sufficient accuracy depends on the circumstance. Someone should conduct an experiment. I have. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Sat, Apr 26, 2014 at 5:05 PM, Paul tik-...@bodosom.net wrote: I think it's fair to wonder why the NTP tar ball doesn't include timepps-Linux.h along with others they do include. On Sat, Apr 26, 2014 at 7:54 PM, Harlan Stenn st...@ntp.org wrote: Is there only one version of that file that is compatible with the places NTP will be built? ... And even if so, why should this issue cost-shift to the NTP Project? So why does the distribution include multiple, platform specific, instances of timepps.h viz. timepps-SCO.h timepps-Solaris.h timepps-SunOS.h ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Le 27 avr. 2014 à 05:36, Paul a écrit : On Sat, Apr 26, 2014 at 5:05 PM, Paul tik-...@bodosom.net wrote: I think it's fair to wonder why the NTP tar ball doesn't include timepps-Linux.h along with others they do include. On Sat, Apr 26, 2014 at 7:54 PM, Harlan Stenn st...@ntp.org wrote: Is there only one version of that file that is compatible with the places NTP will be built? ... And even if so, why should this issue cost-shift to the NTP Project? So why does the distribution include multiple, platform specific, instances of timepps.h viz. timepps-SCO.h timepps-Solaris.h timepps-SunOS.h If you look at those, they are included because the API does not ( or didn't ) exist in the OSs whereas it does for Linux so responsibility should reside there. IIRC, the OP was a heads up which IS useful, but complaints should go to the distributers, rather than here as has been previously mentioned. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
