Slashdot Log In
NTP Pool Project Reaches 500 Servers
Posted by
CowboyNeal
on Sat Jan 14, 2006 11:19 AM
from the about-time dept.
from the about-time dept.
flok 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."
Related Stories
[+]
NTP Pool Reaches 1000 Servers, Needs More 230 comments
hgerstung writes "This weekend the NTP Pool Project reached the milestone of 1000 servers in the pool. That means that in less than two years the number of servers has doubled. This is happy news, but the 'time backbone' of the Internet, provided for free by volunteers operating NTP servers, requires still more servers in order to cope with the demand. Millions of users are synchronizing their PC's system clock from the pool and a number of popular Linux distributions are using the NTP pool servers as a time source in their default ntp configuration. If you have a static IP address and your PC is always connected to the Internet, please consider joining the pool. Bandwidth is not an issue and you will barely notice the extra load on your machine."
This discussion has been archived.
No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
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:3, Insightful)
Trains aren't that reliable (Score:4, Insightful)
And what makes sure the trains are on time?
Confused (Score:4, Funny)
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.
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"
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: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,
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
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.
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? O
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)
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.
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.
Re:500 (Score:5, Funny)
... because they clearly need more publicity to reach something like 5,000 :)
Re:500 (Score:3, Insightful)
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: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: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