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NTP Pool Reaches 1000 Servers, Needs More
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 sounds like a job for Google.
Seriously. They are working to own every other bit of information. Why not "own" the method by which machines maintain time by throwing a thousand machines at it (an insignificant number compared to the 500k or more that make up their own server farm).
"Bandwidth is not an issue and you will barely notice the extra load on your machine."
If that is the case, why do they need more servers?
Selling software wont make you money, selling a service will.
I must mention that right now by signing up for the pool now you also have a chance to get some really cool time keeping equipment. :-)
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ask bjoern hansen
The NTP protocol gives very limited ways of limiting it, so short of just closing down if we can't add servers as fast as traffic is added, no - there isn't much we can do.
The vendor program is one way we're trying to get more control, but all else being equal - more servers helps.
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ask bjoern hansen
Their servers can keep up just fine, or at least the one I run can. My stats show 1GB per month traffic and the ntpd process taking about 1 minute/day of processor time. That has been relatively constant over the year or so the server has been in the pool.
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I think this is just a case of more==better. A bigger pool means more people can use their local zone instead of the global zone, the whole system can handle more clients, less load on servers means even more may be willing to join,
Seriously, it's not that big a deal. Just thow your server into the pool and forget about it.
Hear hear That's consistent with what I have on my server - I never feel it and the more pool, the higher accuracy and ability to account for one-time blips of load like if hardware manufacturer hard codes all their routers to check at the very same time - certainly not impossible to imagine considering what's happened to some university NTP pools. I highly recommend joining.
I think that a better method could be used to encourage diversity. They should take a page from the root DNS servers, or Akamai. Either use BGP anycast, which is what most of the root dns servers do now, which will probably never happen. Or, have a zone that network carriers should use on their local DNS servers, and by way of DNS lookups, encourage their customers to use. ntp.org has a default set of values for say time.overload.ntp.org that reflects the current pool. But I, as an ISP make my DNS servers directly answer queries for overload.ntp.org, and make entires such as:
time IN A 1.2.3.4
time IN A 1.2.3.5
where 1.2.3.4 and 1.2.3.5 are ntp servers on my local network. I don't allow people off my network to query my DNS servers for recursive queries, and the ntp.org DNS servers never tell anyone to use my name servers for this space anyways. This would mean that only my customers that use my DNS servers (about 99%) of them, would ever get answers for my time servers, and they would definitely be close.
And anyone whose network carrier doesn't bother to set this up, still gets generic answers from ntp.org. This works much better than just a big pool full of 1000 servers worldwide, even if you bother to use the country code dns regions, you still aren't always getting an ntp server anywhere near you.
--Nuintari
slashdot : where an opinion can be wrong.
Hi AC,
The NTP Pool monitors the servers and only uses those with accurate time. A server drifting several seconds off would be taken out of the pool until it got fixed.
Also, the NTP daemons are Quite Good at ignoring the servers with Bad Time Keeping.
Using ntpd with the pool servers will give you much much much more accurate time than trying to set it manually after looking at a web page.
- ask
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ask bjoern hansen
Please name one ntp server in the pool that it off by more than .5 seconds? The vast majority are accurate to under .1 seconds. I do not believe that the AC who said these aren't accurate understands how NTP works.
Prime numbers are exactly what Alan Greenspan says they are -S. Minsky
Your google fu sucks, grasshopper.
NTP abuse
Just thow your server into the pool and forget about it.
Isn't that a bit extreme? Should I maybe waterproof it first?
paintball
Like a lot of guys here, we have an atomic self setting clock that works from radio broadcast. They are cheap now and work very well. What I am wondering is, do they make some sort of attachment clock, so it can set your computer's time that way? Like an atomic clock/usb cable connect thingee? Seems like if they did, we wouldn't need all these NTP servers, the government does the radio broadcasting and it is as accurate as it gets.
3 Minutes?!?
.0001ms out of sync with UTC.
I have my machines synced via ntp. ntpq reports than I'm no more than 3ms out of sync with a stratum 1 time server (9ms out of sync with UNSO) and that server is synced with GPS and USNO which as you said is never more than
Eye-balling like you described I can verify that I am within 2000ms of http://time.gov/. I think perhaps that that website may have had issue on the date you saw it being 3 minutes different than what NTP provided.
I'd show you the ntpq output but the lameness filters prevent it.
-USR1
The component that actually determines the stability and accuracy of the real-time clock in your PC is the timebase crystal, not the RTC chip itself.
Like every other component in mass-market electronic gear, it is chosen with minimum cost as the primary consideration. Such "value engineering" also has done away with the tiny trimmer capacitor that used to be present on most motherboards, which could be used (along with a frequency counter) to tweak the oscillator frequency for better accuracy.
For real accuracy, the timebase oscillator needs to be kept at a constant temperature, which isn't possible in a PC that gets turned on and off. Ideally, the crystal (or the entire oscillator circuit) is enclosed in a package equipped with a heater element and temperature sensor, and kept at a constant temperature. Such a circuit is called an OCXO, or Oven Compensated Crystal Oscillator, and is standard equipment on laboratory grade equipment like frequency counters and signal generators.
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The virtualized servers don't usually keep their own time - or when they do they do a poor job.
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ask bjoern hansen
Some how this should all be merged into the bittorrent client.
He who knows not and knows he knows not is a wise man. He who knows not and knows not he knows not is a fool.
Nah. I hear liquid cooling is great for overclocking.
My blog
I'm sure you're right about the low cost of the PC RTC components. However, I still don't understand why I've long been able to buy a watch for $2-$15 that keeps better time than any PC I've had.
For those interested, you can change your Windows time servers to NTP servers in the registry here: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Cur rentVersion\DateTime\Servers]
You want fun, go home and buy a monkey!
Because the number one rule of infrastructure is, "never trust the client." Peer to peer networks are full of malware/trojans/assholes, and generally far too easy to infiltrate with unwanteds.
And while I agree with your sentiment that I can live time being off by a little, I also run a lot of UNIX servers that use NFS heavily. I am far more concerned with all of my network machines agreeing on what time it is on my network, than being correct with the world. I sync two dedicated time servers to the ntp.org pools (soon to be three), and all my internal hosts sync to those two. Being synced with the world is very handy, and generally I would prefer it. But being in agreement with myself is non-negotiable, I just need it.
--Nuintari
slashdot : where an opinion can be wrong.
You do realize all those times are in milliseconds, right? So, the largest difference between your computer and one of the servers is 27 milliseconds, and the leading "-" in front of the hostname means it isn't even being used for synchronization. Also, either you didn't let it settle for a while, or your local computer clock is inaccurate, because you are still polling once a minute. A "healthy" computer clock will lower the poll frequency significantly if the local and estimated net clocks don't jitter much. I did have one machine with a clock that just sucked, so I had to make sure it was a client of another machine which could act as the timekeeper on my home network, and make sure it polled the timekeeper often.
Personally, I don't use the pool, and instead find some stable servers near to my ISP. But you really can't argue against the NTP pool as a default setup, since it works everywhere. So, if it bothers you, find some closer servers or convince your ISP to run a time server (many are already doing so). In both cities I've lived in, I was able to find an open stratum-1 server with a ~20ms delay (Thank you GPS).
When being an NTP server you want the clock to be as accurate as possible.
The server is often locked to other servers and/or to local radio clock receivers.
In a physical machine, there is an accurate hardware timer that is used as the incrementing clock (at micro- or nanosecond rate) and which is frequency locked to the references.
Such hardware does not really exist in the virtual machine, it is emulated, and this emulation is not very good even when you sync to the host.
It is good enough for "wristwatch time" in your virtual machine, but in an NTP server you expect accuracy to the order of milliseconds when externally synced, or microseconds when synced to local radio receivers.
VMware simply is not up to that job.
Although I think ntpd does not have a bad security record (compared to other network services with a long history), I think a better approach to improved security would be to focus on the server code instead of running it in a virtual machine.
BTW, the current version already runs in a chroot environment and as a non-root user in modern Linux distributions.
Life is wet, then you dry.
http://www.timetools.co.uk/
They are a lot more than $20. Now I am just waiting for the customer to
provide another hole in the roof so we can get our GPS antenna outside.
"We can't solve problems by using the same kind of thinking we used when we created them." -- Albert Einstein