NTP Pool Project Reaches 500 Servers 165
A user writes "Finally after 3 years the NTP Pool project has reached 500 servers! The NTP pool project tries to be an accurate and free time-source to every internet-connected device. Everybody who's system has running an NTP daemon which can give an accurate time-indication can join the project. Not only is it handy to have accurate time on your workstation to be able to see when you need to leave the house to catch the train in time, it is also usefull to be able to accurately correlate events between your system and others in case one gets hacked."
oooo so exciting (Score:5, Funny)
Re:oooo so exciting (Score:5, Funny)
And what if you're posting in one?
Re:oooo so exciting (Score:2)
Then you're really a ne... oh, wait this is a post to a discussion about 500 time servers, isn't it?
Re:oooo so exciting (Score:3, Insightful)
Re:oooo so exciting (Score:2)
Re:oooo so exciting (Score:2, Funny)
I've always wondered about that phrase -- who is this "Matters", and why would I want to stuff him?
Even more puzzling: with what?
Trains aren't that reliable (Score:4, Insightful)
And what makes sure the trains are on time?
Re:Trains aren't that reliable (Score:2)
Re:Trains aren't that reliable (Score:2)
My favourite announcements at stations are the ones where they announce that the train is on time. Oh yes.
Re:Trains aren't that reliable (Score:2)
some trains are much worse than others. the worst idea if you wan't to get out quickly is catching a long distance train from its starting station for a few stops because if they have any problems at all then it can stay sitting there for quite some time (half an hour or so in some cases) after its due out time.
mostly local trains round here seem to run within a few
Re:Trains aren't that reliable (Score:2)
But... (Score:2, Informative)
However, congrats. I will continue to use your NTP servers for computer related crap well into the future.
Re:But... (Score:2)
I used to do that. The problem is that I'm not as dumb as I thought. I'd look at my watch and add five minutes. I knew I had until 3:05 for a 3:00 meeting, because my watch was five minutes fast fast.
I decided that a fast clock was doing me more harm than good. (And besides, I have mild OCD.) Now my watch is accurate, and periodically I adjust it so it's within a couple seconds of my computer. (Synced up via the pool.ntp.org, of course.) I know I have until
Confused (Score:4, Funny)
Re:Confused (Score:2, Interesting)
Re:Confused (Score:5, Informative)
Accurate time is important when you are sharing resources with other computers. One example is running a build on an NFS share. If the file timestamps are wrong, then make may do unnecessary compiles, or skip files. Other protocols, like rsync, use timestamps to try to figure out whether updates are needed.
Re:Confused (Score:2)
Tell me about it. In 1999 the operational site which we get our time sync from used their test network (the one connected to our development site) for Y2K testing. We had half a gig of incorrectly date stamped sources. Not a pretty sight.
Re:Confused (Score:2)
It is the lamba term
expressed with combinators. Unlamba is basically an implementation of combinatory logic, but combinators are usually written in capitals.
Re:Confused (Score:3, Interesting)
You would be amazed at the number of folks who figure its allright to do that, I mean its there, why not use it attitude? So no, no admin in his right mind would set that up. Or if he did, he should be dismissed as not
Your machine is going to party like it's 1999 .... (Score:3, Insightful)
There are some nifty bits of nastiness that can be delivered when a machine is privy to having its clock changed from afar.
Re:Your machine is going to party like it's 1999 . (Score:3, Insightful)
A proper NTP implemetation for a computer gathers information from several clock sources. The NTP protocol also has provisions to determine whether a clock is accurate or not based on the responses from other clocks. IIRC, this is called a "false ticker" in the spec.
Re:Your machine is going to party like it's 1999 . (Score:5, Informative)
Nothing.
However, NTP clients uses multiple servers and uses some fairly advanced correlation algorithms to detect outlyers and bad servers. The client configuration is your responsibility. So configure it to use a set of servers that you believe you can trust.
There are some nifty bits of nastiness that can be delivered when a machine is privy to having its clock changed from afar.
Then use the secure protocols.
Re:Your machine is going to party like it's 1999 . (Score:2)
And this exactly why the default OpenBSD settings connect to 8 different ntp pool servers:
Re:Your machine is going to party like it's 1999 . (Score:3, Informative)
All machines in the NTP pool are monitored for quality and if they are bad enough, they won't be put into the pool.
Also, it is recommended that you have at least 3, maybe up to 5, NTP servers so that you can detect a bad NTP server. (If you have one time server, you won't know that anything is wrong. If you have two, you will know something is wrong, but you won't know which NTP server is bad. If you have three or more, you can p
Re:Your machine is going to party like it's 1999 . (Score:2, Insightful)
1.) A proper NTP implementation will only normally change the skew of your clock, so it speeds up or slows down, but does not jump around.
2.) A proper NTP implementation will assume that a clock with a large variance compared to other sources is unreliable, and so it will try not to use it. Of course this assumes you have more than one time source available (and configured).
Re:Your machine is going to party like it's 1999 . (Score:2)
For what it's worth, it's not immediately obvious how to do this. If you were to add multiple servers entries in ntpd.conf, all with pool.ntp.org, then DNS would just cache the first call and you'd point to the same machine all the time. The way to do this is as follows:
server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org
Now you'll get a different server and life will be good. You can also use country
Cool (Score:2, Funny)
Oh, sorry I read that as NNTP
PCs keep lousy time. (Score:2, Interesting)
the clocks simply could not keep accurate time. I've bought 5 buck watches at wal-mart that
kept better time than my PCs. In some cases, they lose (or gain) several (somtimes tens of)
seconds per day.
Is it those Dallas chips that can't keep time? or is it the clock frequency division that
most PCs use?
Re:PCs keep lousy time. (Score:4, Informative)
You will see your 5 buck watch will track the time as good as the Dallas chips.
Temperature affects the speed of clocks.
Re:PCs keep lousy time. (Score:2, Informative)
He stated that the power company tries very hard to regulate the 60 Hz power, such that, as exactly as possible, the required 5,184,000 cycles are sent out every day. As a result, any electric clock (especially one that uses a motor) would have very accurate time.
So why is it, that an electronic device, which you normally plug right into the wall, can't find a source of accurate time? There's a very reliable source of tim
Re:PCs keep lousy time. (Score:2)
Re:PCs keep lousy time. (Score:5, Interesting)
Anyway, about 2pm my board operator at the tv station I was the CE at came running into my office and said the tape machine was going crazy, he though it was running fast and the on air picture wasn't viewable even after being time base corrected.
He'd put that tape in 3 of them without making it work.
As I walked through the control room I was just barely aware that the air conditioning and all the fans in the transmitter seemed to be working real well. I looked at the tape machine, whose main drive motor was a synchronous type whose speed is locked to the powerline frequency, and it did indeed appear to be running fast by a rather large margin. Looking at a motorized wall clock, I noted it was about 18 minutes faster than my trusty timex. So I timed the wall clock second hand against the timex and came up with a powerline frequency of around 71 hz. Voltage was also up a bit, to about 130 at the wall socket, so my transmitter was running very well indeed.
Calling the local electrickery people, I got a number for the WAPA control center up in Utah someplace and called them up. Argueing with the sexytary for a couple of minutes I finally got through to an operator on duty, introduced myself as the CE at a tv station down in New Mexico and then asked him if his clocks were fast. He first didn't get it, then checked his watch against the wall clock and muttered OMG. He said I'll get that fixed asap and I hung up since there wasn't a watts line account there & Ma Bell was very proud of her daytime business rates...
About 2 minutes later you could hear the fans and stuff gradually slowing down, and it finally settled at about 59hz until time had caught up with the wall clocks again.
I think some folks either got some overtime or got to go home a few minutes early that day, so there were what one could have called collateral damages, if even only to the economy west of the mississippi. The whole west side of the country is all synched up, presumably so is whats east of the river. Anyway, it was such an odd occurance that I still have to grin when I recall it nearly 30 years later. One of those things that couldn't ever happen, but did.
--
Cheers, gene
more useful for nfs, clustering (Score:2)
Re:more useful for nfs, clustering (Score:2)
Well, it does matter for Kerberos / MS Active Directory authentication.
In any shared software development environment, time needs to be accurate or your builds will fail in strange ways.
And I'd like to be able to correllate our syslog output, too...
Re:more useful for nfs, clustering (Score:3, Funny)
Yeah, I didn't think it mattered too much on non-critical systems either. Then I ran MythTV and missed the last couple minutes on my Futurama episodes. Never again.
Re:more useful for nfs, clustering (Score:2)
If my computer (routinely synced via NTP) changes to, say, 12:00:00, and it takes ten seconds for my desk clock to changes from 11:59 to 12:00, I don't care at all.
But it's not uncommon to rack up 15-minute differences between clocks. That, I'd argue, is a very big problem.
Why we removed our servers from the pool... (Score:5, Interesting)
I finally shut it down after one particular call, the third that week, where the caller was rude and abusive when I suggested that he should be doing more investigation about the traffic before calling someone else to complain about it. Being a public service, it's just not something that scales well to have to field these calls. I hated to do it, but it was just too much of a distraction.
I'm not saying that you shouldn't add your servers to the pool... I just thought it was an amusing story.
Sean
Re:Why we removed our servers from the pool... (Score:3, Interesting)
Uh, your servers are supposed to only reply with *ONE* packet.
That said, I have also had a few people complain to me about my machine attacking them because they have configured their machine to use the NTP pool. Over the last 2 years, it has totalled around 3, so you must have had really bad luck.
Overall, I have been very happy with my involvement with the NTP
Re:Why we removed our servers from the pool... (Score:2)
Be that as it may, tcpdump of that particular remote address showed one
request coming in and 10 responses going back, spaced at 1 second
intervals. This may be because the remote was making a request that
resulted in the 10 responses. I'd doubt it was a but in ntpd, but that
may be as well.
Sean
Re:Why we removed our servers from the pool... (Score:4, Informative)
See the "iburst" keyword in ntp.conf. This results in a burst of ntp packets at startup.
Re:Why we removed our servers from the pool... (Score:2)
Some web surfing and newsgroup posting finally brought some understanding.
New Way uses HW (Score:5, Informative)
It is great that NTP is so widely distributed. It is typical that at the moment the old technology is finally working, there is an altogether better solution.
Re:New Way uses HW (Score:3, Insightful)
Besides, what a GPS receiver gives you is a stratum 1 host. What are you going to do, get a receiver per machine? Of course not, you connect it to one box with a NTP server, and make the rest synchronize with it.
Perhaps the usefulness of public NTP servers is somewhat less now, but they're still good to have. I'm sure at many companies buying a GPS receiver could be co
Re:New Way uses HW (Score:2)
If time really matters, you'll have one per machine. I wouldn't say "of course not," as you did. They only cost about $75 (US) now.
Re:New Way uses HW (Score:3, Insightful)
Also, not everyone wants to setup an antenna on the roof and wire it into the computer room.
For typical computer network purposes (where relative time accuracy is more important than absolute accuracy), NTP is a very good solution. It will get all systems on your lan within milliseconds or better, and the whole network within tens of milliseconds. It will be better than a message-based (no
Re:New Way uses HW (Score:5, Insightful)
Of course, most machines locked in a rack in a hosting facility don't have even the slightest chance of seeing enough sky to lock onto GPS, so it's safe to say that NTP's death or obsolesence is premature to announce just yet. :-)
--
-Chuck
PS: O Slashdot wizards, why does Slashdot's posting filter claim ntpq output is lame?
It's a conspiracy, I tell you, to force me to write more text!
Bah, that doesn't work, the lameness filter doesn't like a line filled with "=" signs at all, even if I use an <ecode> tag.
Re:New Way uses HW (Score:4, Insightful)
Unless your data center is inside a shielded room / underground / in the center of your building.
It is great that NTP is so widely distributed. It is typical that at the moment the old technology is finally working, there is an altogether better solution.
Its not a better solution - its a better solution in some cases.
NTP has the massive advantage of working anywhere you have a network connection and not requiring expensive hardware (GPS hardware you can attach to a PC & match the reliability of NTP is not your yum-cha $75 GPS unit)
Re:New Way uses HW (Score:3, Informative)
Also, the 1pps output of a $75 GPS unit is considerably more accurate than NTP if your network is subject to *any* sort of variable delay, which of course packet-based networks are.
Not that NTP isn't useful, just don't
Re:New Way uses HW (Score:2)
None of the $75 GPS units I've looked at have had PPS. I thought PPS-enabled receivers were a lot more expensive than your run-of-the-mill GPS receiver?
Re:New Way uses HW (Score:2)
When you find an RS232-interfaced receiver, chances are that it provides PPS on the DCD pin.
I am using OEM module GPS receivers here (bare printed circuit boards that are/were used by system integrators to build systems) and the three different types I have all provide a PPS signal.
These are sometimes available as surplus components.
Re:New Way uses HW (Score:2)
On a LAN, you can expect submillisecond accuracy out of NTP. At least when your OS clock can be phaselocked to an external reference.
Of course it will be difficult when you are syncing over an asymetrically loaded Internet link.
Timing from cellular signals... (Score:2)
GSM and other systems that use TDMA as a radio access method can tolerate more timing trouble than CDMA. As far as I know, a TDMA site doesn't need a good master clock, since timing slips between sites are uni
Re:Timing from cellular signals... (Score:2)
(I think I once read somewhere that a single manufacturer had implemented an
Re:New Way uses HW (Score:2)
NTP is a cheap and effective way of distributing time to systems that do not need high-quality time.
Re:New Way uses HW (Score:2)
For Linux and Macintosh, there are ways you can get at least the proprietary Garmin GPS's to work. See http://lancej.blogspot.com/2005/10/using-garmin-et rex-vistac-with.html [blogspot.com]
I've had no problems using GPS with Linux, but I bet it'll get worse over time, as I believe the vendors will continue to try harder to lock customers into their own software packages.
Re:New Way uses HW (Score:2)
Recommended NTP clients (Score:2, Informative)
Re:Recommended NTP clients (Score:2)
Re:Recommended NTP clients (Score:2)
Re:Recommended NTP clients (Score:2)
I run a pool server: some interesting bits (Score:4, Informative)
There is modest protection against bad servers in the pool. The time from pool servers is monitored and if a server seems insane it's taken out of the rotation.
My pool server gets about 14 requests a second from about 100,000 different IP addresses a day. Sadly, a lot of those requests are junk; 100 IP addresses account for 1/3 of all the requests I get. Fortunately NTP is a very lightweight protocol, so you can mostly ignore the spammy clients.
Re:I run a pool server: some interesting bits (Score:2)
I didn't realize Microsoft did this, but I know when I started buying Apple, I sure noticed it, and thought it was a very nice touch. Small things like this can give a lot of polish to a product.
UIC's "unofficial" time server (Score:5, Funny)
The naming standard for desktop machines was to take the employee's first name and concatinate it with the first letter of their last name. So my desktop machine was named "johns.cc.uic.edu". Tim's machine was named "time.cc.uic.edu" because his last name began with "E". (cc meaning a "computer center" machine.)
Apparently many many university departments and users poked around and discovered what was obviously an official time server and configured their computers to synchronize to Tim's desktop machine. Tim, of course, had set his computer's clock by the office clock and never given it a second thought.
Obligatory Grammar/Spelling Nazi (Score:2, Offtopic)
Public NTP server? (Score:2)
I don't do any address restriction on the NTP server. Anybody doing a UDP s
Re:Public NTP server? (Score:3, Informative)
in this context, public probably means that the server's listed by pool.ntp.org [ntp.org]. isc also maintains a list of stratum 1 and 2 servers [isc.org], some of which are publicly-accessible.
Re:Public NTP server? (Score:2)
Listing it on pool.ntp.org of course is an explicit permission to use it.
NTP servers as distro usage trackers (Score:2)
Does anyone know if these distros use traffic to their servers to track installed base? Or are they just being extra friendly?
Re:NTP servers as distro usage trackers (Score:2)
Re:NTP servers as distro usage trackers (Score:2)
Here in FC3 it is the pool.ntp.org servers.
I believe Ubuntu sets the default to an ubuntu project server.Yes
Does anyone know if these distros use traffic to their servers to track installed base?I assumed this was the case with Ubuntu. But I don't really know.
Why I stopped participating (Score:2)
Some people went as far as to write scripts that would add bad clients to the s
Re:Why I stopped participating (Score:2)
Ain't that the truth.
Blocking some clients simply causes them to increase their polling rate !
Ugh. But surely they wouldn't increase to more than once per second... would they?
I wish that ntpd would keep track of who it sent a KOD to and start ignore all packets from them (which I thought it was supposed to do now, but it doesn't). That would cu
Re:Why I stopped participating (Score:2)
Re:Why I stopped participating (Score:2)
Proof reading!!! (Score:2)
"usefull"
What's up with you guys? I'm not even a native speaker. You were just a "should of" and an "it's" short of a crap submission.
6 gig per month? (Score:2)
According to the project web page [ntp.org] you can expect 10-20Kbit/sec of traffic, which works out to 6 gigabytes per month of traffic. It doesn't say which direction but I suspect NTP would be pretty symetrical so this would triple the inbound volume to my co-lo.
Thats a lot of volume for me, so I don't see how I could contribute a server.
Its a shame that they can't include a dynamic DNS hack into the system. My home system has heaps of volume at a fixed price, but it is on a dynamic IP.
Re:6 gig per month? (Score:2)
Yeah, then we could have thousands of AOL users contributing. With the added reliability we'd get from all those extra servers, NTP could be used for some really critical functions. You know, nuclear power stations, missile defence systems, shit like that. I know I'd feel safer.
Re:6 gig per month? (Score:2)
For people paying per GB of transfer, it could be a big deal. These days, though, 1,000GB/month is the normal allocation for dedicated servers, so an extra 6GB of traffic would be nothing. (Assuming they weren't using 994 a month...) I'd be concerned about issues like server load instead.
Re:6 gig per month? (Score:2)
This is not a matter of what "they" can hack. Most NTP clients do not do a DNS request before every NTP packet they send out, but only resolve the address when initialized and then make queries to a fixed address.
That would mean that systems that are not rebooted often would lose contact when your system changes address.
Re:500 (Score:5, Funny)
... because they clearly need more publicity to reach something like 5,000 :)
Re:500 (Score:3, Insightful)
Really? (Score:2)
Re:500 (Score:2)
A time service is a sensitive, but important, service to use. Having many reliable time servers to choose among will lessen the security risk of hacked servers, or servers just out of sync for some reason. A public timer server will see alot of traffic, so not everyone has the bandwidth nor the hardware.
The OpenBSD Network Time Protocol daemon [openbsd.org] selects randomly among various time servers, and is very easy to setup. However, if there are few time servers available, there is
Re:500 (Score:4, Informative)
Last year, the pool was falling behind on servers. More clients were joining than servers, so the load on each server was growing. Since then, Ask Bjørn Hansen has created a bunch of automated scripts to handle all of the servers and the server growth has taken off. We still need more servers, and 500 is a nice round number to give as an excuse to say "Please join the NTP pool!".
Stratums (Score:5, Insightful)
It would also be nice if ISPs would set up their own pools (and advertise them) so clients wouldn't have to go off network, and then if end-users would would set up their own pool for their networks. Not every machine that needs accurate time has to be at stratum-2 or stratum-3, especially workstations. The NTP Pool website makes it look like it is a good idea if every machine on a network syncs to the NTP Pool, instead of setting up internal servers, which is how NTP is really designed to work.
Re:Stratums (Score:2, Informative)
- Traceroute off your network, e.g. to cnn.com
- For each hop in the route, run 'ntpdate -q '
9 times out of 10, you'll find an NTP server one or two hops away.
Re:Stratums (Score:2)
Re:Stratums (Score:2)
Re:Stratums (Score:2)
Re:Stratums (Score:2)
Auto-configure ntp via dhcp (Score:3, Interesting)
Agreed. Most do, but as you mention, don't advertise them. I am not sure how many people would actually know what to do with them if they were advertised though.
It would be quite slick if they advertised them via DHCP, and clients used that info to auto-configure their ntp client. All quite possible and very easy to do by the ISP. NTP servers can be advertised via dhcp.
http://gento [gentoo-wiki.com]
Re:Auto-configure ntp via dhcp (Score:2)
Am I the only one that thinks dhcpcd overwriting files by default is a bad thing? There are a couple others it'll zap too, if you aren't paying attention:
From the man page:
-N - disables overwriting of ntp.conf
-R - disables overwriting resolv.conf
-Y - disables overwriting yp.conf
Re:Auto-configure ntp via dhcp (Score:2)
Re:Stratums (Score:2)
The NTP Pool website makes it look like it is a good idea if every machine on a network syncs to the NTP Pool, instead of setting up internal servers, which is how NTP is really designed to work.
From http://www.pool.ntp.org/use.html [ntp.org], second to last line in "Additional Notes":
If you are synchronising a network to pool.ntp.org, please set up one of your computers as a time server and synchronize the other computers to that one. (you'll have some reading to do - it's not difficult though. And there's al
Re:Stratums (Score:2)
Oops, my bad. You are right. I think that I need to work on my reading comprehension...
Re:I just use my watch (Score:2)
Re:I just use my watch (Score:2)
There are also radio receivers that listen to WWV (same as
Re:I just use my watch (Score:2)
Re:wow... (Score:2, Funny)
Re:Have seen better performance. (Score:2)