Re: [ntp:questions] multiple instances of NTP on different interfaces
On 2013-03-07, Abu Abdullah falcon.sh...@gmail.com wrote: On Thu, Mar 7, 2013 at 12:41 AM, E-Mail Sent to this address will be added to the BlackLists Null@blacklist.anitech-systems.invalid wrote: unruh wrote: He has gotten himself totally confused about what his real job and desires are, it seems to me. Perhaps its something like, he needs to provide ntp to the pool due to really high vendor zone useage by his appliances? Still sounds like two machines would be better than one. Both are important for us. I can conclude from all the responses that there is no an out of the box solution for the same. I need to have separate OS (or zone). Well, you are not listening. someone suggested having two versions running with one having only the local clock as server. But, you have also said that one of them was a critical internal server of time. As such, as I have said, it is stupid to have that machine serving the public for all the reasons you stated as to why you wanted two separate versions running. All of those reasons are far more cogent for running separate machines. And if you do not have the $30 for a raspberry Pi to act as the public server, then I would advise you to get the internal network up and running well first, and then go for the public server when you can spare another machine. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] 1s offset
On 06/03/2013 20:22, unruh wrote: [] That should all be in the same second. The nmea sentence cannot come before the PPS, so the one second should all be between the PPS pulse and the next one. The problem occurs if the end of the sentence comes after the next pulse occurs. The code should probably use the beginning of the sentence, not the end, to mark the time. It can always throw away the timestamp if it is not needed. Or at least once it knows that the appropriate sentence is coming. (the first four or 5 characters received). [] Yes, it /should/ be the same second, but it depends on how NTP may, or may not, round the value 0.6, for example. I haven't looked at the code to check the actual behaviour. The problem of going into the next second, requiring a fudge of over 1 second, did occur with one lot of Garmin firmware, but was fixed. Yes, it was whether the beginning or end of the sentence was used that made me wonder about the different behaviour of different NTP versions. I recall that in the Windows version it is the end of the first sentence received which has the PPS timestamp substituted as the time of reception. I am less familiar with the UNIX versions. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] multiple instances of NTP on different interfaces
Uwe Klein u...@klein-habertwedt.de wrote: Abu Abdullah wrote: On Thu, Mar 7, 2013 at 12:41 AM, E-Mail Sent to this address will be added to the BlackLists Null@blacklist.anitech-systems.invalid wrote: unruh wrote: He has gotten himself totally confused about what his real job and desires are, it seems to me. Perhaps its something like, he needs to provide ntp to the pool due to really high vendor zone useage by his appliances? Still sounds like two machines would be better than one. Both are important for us. I can conclude from all the responses that there is no an out of the box solution for the same. I need to have separate OS (or zone). Look into changeroot prisons. Some (Linux) distributions already run ntpd in a change rooted prison. Should be easy to adapt that to a dual setup. This isolates only the filesystem, not the network sockets. Het described a problem with the sharing of the network sockets. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] outlyer / falseticker
Hi, Why is a clock decided to be a falseticker/outlyer? Does it have to do with the stratum or are other factors the decision factor? e.g.: ntpq pstatus 60996 associd=60996 status=9314 conf, reach, sel_outlyer, 1 event, reachable, srcadr=x.x.x.x, srcport=123, dstadr=x.x.x.x, dstport=123, leap=00, stratum=4, precision=-24, rootdelay=37.201, rootdispersion=153.793, refid=x.x.x.x, reach=377, unreach=0, hmode=3, pmode=4, hpoll=6, ppoll=6, flash=00 ok, keyid=0, ttl=0, offset=2.499, delay=9.095, dispersion=2.698, jitter=0.115, reftime=d4e2ecad.0fbfa4b2 Thu, Mar 7 2013 11:38:37.061, org=d4e2f01d.d9645cf8 Thu, Mar 7 2013 11:53:17.849, rec=d4e2f01d.d9eb2de5 Thu, Mar 7 2013 11:53:17.851, xmt=d4e2f01d.d78e8703 Thu, Mar 7 2013 11:53:17.842, filtdelay= 9.129.169.169.109.119.289.739.16, filtoffset=2.502.532.472.502.572.612.572.76, filtdisp= 0.000.961.912.903.864.805.756.72 Folkert van Heusden -- Feeling generous? - http://www.vanheusden.com/wishlist.php -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
folkert writes: Hi, Why is a clock decided to be a falseticker/outlyer? It's 0300 where I am and I'm about to fall asleep. See ntp_proto.c, and look for falseticker and SEL_SANE. Does it have to do with the stratum or are other factors the decision factor? There are other factors. Sorry I'm not being more helpful. H ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] multiple instances of NTP on different interfaces
Rob wrote: Uwe Klein u...@klein-habertwedt.de wrote: Abu Abdullah wrote: On Thu, Mar 7, 2013 at 12:41 AM, E-Mail Sent to this address will be added to the BlackLists Null@blacklist.anitech-systems.invalid wrote: unruh wrote: He has gotten himself totally confused about what his real job and desires are, it seems to me. Perhaps its something like, he needs to provide ntp to the pool due to really high vendor zone useage by his appliances? Still sounds like two machines would be better than one. Both are important for us. I can conclude from all the responses that there is no an out of the box solution for the same. I need to have separate OS (or zone). Look into changeroot prisons. Some (Linux) distributions already run ntpd in a change rooted prison. Should be easy to adapt that to a dual setup. This isolates only the filesystem, not the network sockets. Het described a problem with the sharing of the network sockets. Is there an uncircumventable need to share? I would add a set of IP's to the loopback or link-local interface. Have instance A of ntp use 169.254.0.22 Have instance B of ntp use 169.254.0.44 as access to a common network. voila? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
Why is a clock decided to be a falseticker/outlyer? It's 0300 where I am and I'm about to fall asleep. See ntp_proto.c, and look for falseticker and SEL_SANE. Ok. While reading through the source, I encountered a lot of unusual comments: * Initially, we populate the island with all the rifraff peers rifraff? * that happen to be lying around. Those with seriously * defective clocks are immediately booted off the island. Then, * the falsetickers are culled and put to sea. The truechimers cullend and put to sea? * remaining are subject to repeated rounds where the most * unpopular at each round is kicked off. When the population * has dwindled to sys_minclock, the survivors split a million * bucks and collectively crank the chimes. split a million bucks? * candidates, the Albanians have won the Byzantine wars and * correct synchronization is not possible. byzantine wars? I would like to suggest to use language without any ambiguity. Yes, it is probably more fun for the developer this way, but for others, especially the ones who are not native English speakers, these texts are confusing. For example the survivors split a million bucks: is it supposed to be funny or does it have a special meaning? Does it have to do with the stratum or are other factors the decision factor? There are other factors. Sorry I'm not being more helpful. No problem, don't feel obliged. Folkert van Heusden -- www.TrustedTimestamping.com is a service that enables you to show that at a certain point in time, you had access to a hash-value reflecting the contents of a file (this file can be a word document, a jpeg image, everything). -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
Okay, it can be a little obtuse, especially if you don't know the references. The two specific references that are being used here are the reality television show Survivor and The Byzantine Generals Problem, an algorithm for detecting misbehaving parts of a system, in this case an NTP server. Comments inline: On 3/7/2013 7:22 AM, folkert wrote: Ok. While reading through the source, I encountered a lot of unusual comments: * Initially, we populate the island with all the rifraff peers rifraff? Riff Raff: disreputable person. This is saying initially use all of the candidate servers, no matter how good or bad they appear. * that happen to be lying around. Those with seriously * defective clocks are immediately booted off the island. Then, * the falsetickers are culled and put to sea. The truechimers cullend and put to sea? Seriously defective means not selectable because either the server is not in sync or the root sync distance is too large, or it doesn't meet administrative criteria (stratum too low, too high, configured noselect, or makes a sync loop). The algorithm takes what is left and looks for false tickers. This is a little tricky to describe in English, but it essentially looks at the offset and error bars from all the remaining servers and determines a consensus interval in which the true offset lies. A falseticker is any server with an offset that does not lie within that interval. If a server is tagged as a falseticker, it is removed from further consideration, which is the what culled and put to sea means in this case. * remaining are subject to repeated rounds where the most * unpopular at each round is kicked off. When the population * has dwindled to sys_minclock, the survivors split a million * bucks and collectively crank the chimes. split a million bucks? This is where the Byzantine General solution comes into play. We repeatedly try to narrow the consensus interval of the remaining servers until we get the smallest possible interval. All servers with offsets in the smallest interval are candidates for selection. It is possible that there is no consensus and it is not possible choose a server that has any better likelihood of being correct than any other and they do not agree, which leads us to the next comment. * candidates, the Albanians have won the Byzantine wars and * correct synchronization is not possible. byzantine wars? The Byzantine Generals Problem is based on an allegory with the problems the generals in the Byzantine empire had fighting the Albanians. This comment is saying if there is no consensus among the Byzantine generals, then they cannot act and Albania wins the war. That is, no servers are selectable. After that there is more culling of the rest, using jitter and distance to find the best quality of time of the remaining servers. And then the weighting algorithm may come into play to get the final offset used. Servers culled at this point at marked as Excess, since they had good time, but the culling continues until there are only sys_minclock servers left. Hope that make it more clear. Brian. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
Okay, it can be a little obtuse, especially if you don't know the references. The two specific references that are being used here are the reality television show Survivor and The Byzantine Generals Problem, an algorithm for detecting misbehaving parts of a system, in this case an NTP server. [ skipped explanation ] Thanks! Makes it much clearer. Maybe this can be written down in a FAQ on the ntp-website? No need to elaborate or make it more document-like, I found it very clear as you've written it down. regards Folkert van Heusden -- -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] 1s offset
On 2013-03-07, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: On 06/03/2013 20:22, unruh wrote: [] That should all be in the same second. The nmea sentence cannot come before the PPS, so the one second should all be between the PPS pulse and the next one. The problem occurs if the end of the sentence comes after the next pulse occurs. The code should probably use the beginning of the sentence, not the end, to mark the time. It can always throw away the timestamp if it is not needed. Or at least once it knows that the appropriate sentence is coming. (the first four or 5 characters received). [] Yes, it /should/ be the same second, but it depends on how NTP may, or may not, round the value 0.6, for example. I haven't looked at the code to check the actual behaviour. It does not round the time value. It uses it all ( to themicrosecond). The problem of going into the next second, requiring a fudge of over 1 second, did occur with one lot of Garmin firmware, but was fixed. 18x. Yes, it was whether the beginning or end of the sentence was used that made me wonder about the different behaviour of different NTP versions. I recall that in the Windows version it is the end of the first sentence received which has the PPS timestamp substituted as the time of reception. I am less familiar with the UNIX versions. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] 1s offset
On 07/03/2013 17:36, unruh wrote: [] Yes, it /should/ be the same second, but it depends on how NTP may, or may not, round the value 0.6, for example. I haven't looked at the code to check the actual behaviour. It does not round the time value. It uses it all ( to themicrosecond). If converting a seconds+fraction number to seconds, it must either round or truncate. It's converting a 64-bit number to a 32-bit one, effectively, when determining the nearest second. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
On 2013-03-07, folkert folk...@vanheusden.com wrote: Why is a clock decided to be a falseticker/outlyer? It's 0300 where I am and I'm about to fall asleep. See ntp_proto.c, and look for falseticker and SEL_SANE. Ok. While reading through the source, I encountered a lot of unusual comments: * Initially, we populate the island with all the rifraff peers rifraff? * that happen to be lying around. Those with seriously * defective clocks are immediately booted off the island. Then, * the falsetickers are culled and put to sea. The truechimers cullend and put to sea? * remaining are subject to repeated rounds where the most * unpopular at each round is kicked off. When the population * has dwindled to sys_minclock, the survivors split a million * bucks and collectively crank the chimes. split a million bucks? * candidates, the Albanians have won the Byzantine wars and * correct synchronization is not possible. byzantine wars? I would like to suggest to use language without any ambiguity. Yes, it is probably more fun for the developer this way, but for others, especially the ones who are not native English speakers, these texts are confusing. For example the survivors split a million bucks: is it supposed to be funny or does it have a special meaning? I am positive that no matter where you live, the television show Survivor has made its appearance. If you do not like humour ( which I agree can in some cases not translate well, but you are reading it in English) then reading David Mills' code is probably not for you. Does it have to do with the stratum or are other factors the decision factor? There are other factors. Sorry I'm not being more helpful. No problem, don't feel obliged. Folkert van Heusden ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
unruh writes: I am positive that no matter where you live, the television show Survivor has made its appearance. I have never seen it: I do not watch television. I have only a vague idea what it is about (and no interest in learning more). If you do not like humour ( which I agree can in some cases not translate well, but you are reading it in English) then reading David Mills' code is probably not for you. I appreciate Dr. Mills' humor. However, I do not think that it is desireable to make detailed familiarity with USA popular culture essential for the comprehension of documentation. It's quite possible to have an adequate grasp of written English without knowing what Survivor is (or knowing the rules of baseball: this applies to the ever-popular sports analogies as well as to TV references). -- John Hasler jhas...@newsguy.com Dancing Horse Hill Elmwood, WI USA ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
On 2013-03-07, John Hasler jhas...@newsguy.com wrote: unruh writes: I am positive that no matter where you live, the television show Survivor has made its appearance. I have never seen it: I do not watch television. I have only a vague idea what it is about (and no interest in learning more). If you do not like humour ( which I agree can in some cases not translate well, but you are reading it in English) then reading David Mills' code is probably not for you. I appreciate Dr. Mills' humor. However, I do not think that it is desireable to make detailed familiarity with USA popular culture essential for the comprehension of documentation. It's quite possible to have an adequate grasp of written English without knowing what Survivor is (or knowing the rules of baseball: this applies to the ever-popular sports analogies as well as to TV references). It was, I believe, and attempt to make the procedure more comprehensible by making an analogy to the TV show. Of course, if you have not seen the TV show, the analogy does not help, but even then I think it is comprehensible, simply because the rules of Survivor are so simple. But clearly your milage may vary. Anytime you explain, you are assuming that the explanation refers to concepts more familiar to the reader than the original concepts. voting -- what do you do if you come from Turkmenistan, where voting always had a preordained output? Should you never refer to voting when explaining what happens in the reduction process? Similarly for the other explanations. While I agree that in this case the explanation was too cutesy, that is also a judgement call. I do not think that anyone will mistake a reference to a million dollars as a real economic transaction. I think even the original complainant saw it as a metaphore, but just was not sure what the metaphore referred to. Again, the reference to riffraff is a metaphore which could quickly havee been illuminated by a look at a dictionary. Second entry in a google search gives the Wikipedia definition ( the first reference a rapper, and perhaps that could confuse). Ie, it seems that when one reads a language one does not understand well, when you come across a term you do not understand, recourse to a dictionary would be a good idea, rather than complaining on usenet. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
folkert writes: Why is a clock decided to be a falseticker/outlyer? It's 0300 where I am and I'm about to fall asleep. See ntp_proto.c, and look for falseticker and SEL_SANE. Ok. While reading through the source, I encountered a lot of unusual comments: * Initially, we populate the island with all the rifraff peers rifraff? Unacceptable quality. * that happen to be lying around. Those with seriously * defective clocks are immediately booted off the island. Then, * the falsetickers are culled and put to sea. The truechimers culled and put to sea? Selected and removed. * remaining are subject to repeated rounds where the most * unpopular at each round is kicked off. When the population * has dwindled to sys_minclock, the survivors split a million * bucks and collectively crank the chimes. split a million bucks? selected as the winners. * candidates, the Albanians have won the Byzantine wars and * correct synchronization is not possible. byzantine wars? The Byzantine General problem - if you want to protect against N cases of insanity you have to have at least 2N+1 choices to select from. That way the sane sources will always be able to out vote the insane sources. I would like to suggest to use language without any ambiguity. Yes, it is probably more fun for the developer this way, but for others, especially the ones who are not native English speakers, these texts are confusing. For example the survivors split a million bucks: is it supposed to be funny or does it have a special meaning? It's Millsspeak. See http://www.eecis.udel.edu/~mills/david.html, the 2nd paragraph. H ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
byzantine wars? I would like to suggest to use language without any ambiguity. Yes, it is probably more fun for the developer this way, but for others, especially the ones who are not native English speakers, these texts are confusing. For example the survivors split a million bucks: is it supposed to be funny or does it have a special meaning? I am positive that no matter where you live, the television show Survivor has made its appearance. Never seen it. And yes, it was on television over here in the Netherlands. If you do not like humour (which I agree can in some cases not translate well, but you are reading it in English) then reading David Mills' code is probably not for you. It is not about liking humour, it it about making it more difficult to comprehend what is going on in a piece of code. And comments with riddles in them makes this more difficult. Folkert van Heusden -- Curious about the inner workings of your car? Then check O2OO: it'll tell you all that there is to know about your car's engine! http://www.vanheusden.com/O2OO/ -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
Anytime you explain, you are assuming that the explanation refers to concepts more familiar to the reader than the original concepts. voting -- what do you do if you come from Turkmenistan, where voting always had a preordained output? Should you never refer to voting when explaining what happens in the reduction process? Similarly for the other explanations. You're using an hyperbole. Ie, it seems that when one reads a language one does not understand well, when you come across a term you do not understand, recourse to a dictionary would be a good idea, rather than complaining on usenet. Referring to a secondary information source pulls you (well, at least me) out of the thought-train. This is not code which opens a file and sends it contents to the terminal, this is complex codes with all kinds of algorithms that need to be comprehended to understand to full picture. Folkert van Heusden -- MultiTail er et flexible tool for å kontrolere Logfiles og commandoer. Med filtrer, farger, sammenføringer, forskeliger ansikter etc. http://www.vanheusden.com/multitail/ -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
unruh wrote: I am positive that no matter where you live, the television show Survivor has made its appearance. I bet they don't get that in North Korea. -- E-Mail Sent to this address blackl...@anitech-systems.com will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
On 2013-03-07, E-Mail Sent to this address will be added to the BlackLists Null@BlackList.Anitech-Systems.invalid wrote: unruh wrote: I am positive that no matter where you live, the television show Survivor has made its appearance. I bet they don't get that in North Korea. Not at all clear. Beautifully shows the bankruptcy of the Western lifestyle, the insane competition for limited resources, the laughing at others weakness and misfortune, the terrors of individuals pitted against each other. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
unruh wrote: BlackLists wrote: unruh wrote: I am positive that no matter where you live, the television show Survivor has made its appearance. I bet they don't get that in North Korea. Not at all clear. Beautifully shows the bankruptcy of the Western lifestyle, the insane competition for limited resources, the laughing at others weakness and misfortune, the terrors of individuals pitted against each other. I'm sure they are missing out on a treasure trove of bad capitalist examples, from many TV shows; However they can't control the content, so are unlikely to allow it in general. http://en.wikipedia.org/wiki/Media_of_North_Korea http://en.wikipedia.org/wiki/Korean_Central_Television -- E-Mail Sent to this address blackl...@anitech-systems.com will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
folkert wrote: Maybe this can be written down in a FAQ on the ntp-website? No need to elaborate or make it more document-like, I found it very clear as you've written it down. http://www.eecis.udel.edu/~mills/ntp/html/warp.html http://www.eecis.udel.edu/~mills/ntp/html/select.html http://www.eecis.udel.edu/~mills/ntp/html/cluster.html http://www.eecis.udel.edu/~mills/book.html http://www.ietf.org/rfc/rfc5905.txt -- E-Mail Sent to this address blackl...@anitech-systems.com will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] Active Peer vs. PPS
Hi I have a question regarding a Linux with PPS Kernel [*1] (actually a raspberry pi with an adafruit GPS [*2]). From ntp.conf: server 127.127.20.0 prefer mode 17 fudge 127.127.20.0 flag1 1 flag3 0 time2 0.496 server ntp1.home4u.ch iburst server ntp2.home4u.ch iburst Now I get from ntpq -p: root@raspberrypi:~# ntpq -p remote refid st t when poll reach delay offset jitter == oGPS_NMEA(0) .GPS.0 l 53 64 3770.000 0.015 0.003 *ntp1.home4u.ch .PPS.1 u 57 64 377 11.118 2.247 1.317 +ntp2.home4u.ch .DCFa. 1 u 58 64 377 11.315 2.654 0.333 +ntp3.home4u.ch .DCFa. 1 u 21 64 377 17.514 -1.807 2.797 If I let a Client sync to the raspi it says that it's a stratum 1 server (which means the server is syncing to GPS/PPS), but why is the active peer always an external server (no matter which server I use)? Is this correct? Thanks, Fabian [*1]Linux raspberrypi 3.1.9adafruit-pps+ #21 PREEMPT Sun Sep 2 10:57:58 PDT 2012 armv6l GNU/Linux [*2]http://www.adafruit.com/products/746 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
