NTP Pool Reaches 1000 Servers, Needs More 230
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."
Google (Score:5, Interesting)
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).
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Re:Google (Score:5, Informative)
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You can have five billion machines all hitting a single "atomic clock". Or you could have a few servers hit it and hundreds of servers that sync up with *those* servers. Seriously, even in cases where all machines of an organization or university or corporation sync off one single internal NTP server (which itself them hits one of the servers in this pool, I'd presume) -- you're still talking about billions of machines that need to have the proper time synced on a daily bases acros
huh? (Score:5, Interesting)
If that is the case, why do they need more servers?
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Re:huh? (Score:5, Interesting)
Re:huh? (Score:5, Funny)
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I modded this post Off Topic and I meant it!
Oh shit, did I just post?
Re:huh? (Score:5, Informative)
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I'd like to think that if my computer is say, 100ms off clock time that I won't be much affected.
I can't think of one instance where being off by even a half a minute or so that I would be affected.
Does anyone actually know the answer posed by the OP?
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If you're using SNMP to log equipment on the network, it helps to have everything as lined up as you can. Now, if you're a company doing this, typically you have your own time server and don't rely on this pool. But there are benefits to some to have more exacting time across all devices.
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A lot of things depend on that if A happens before B, it gets timestamped as <= B. Compiling things
Re:huh? (Score:4, Insightful)
The first thing that comes to mind is remote logging. If I have several machines logging to some remote machine somewhere (as you should on any non-trivial system, to make a log falsification more difficult), it makes log analysis a lot easier if I know that the timestamps in the log are accurate and consistent across machines. Particularly if you ever have to dig through a break-in (or what you think might be a break-in), or just user stupidity, where you want to match actions taken on one machine to results on another.
At the very least, you want to make sure that all the clocks on the machines are accurate to at least the smallest interval of time that you might have two timestamps on the log apart by. Or if that's not possible, at least within a span so that the same human-initiated command will be discernible across the system at the same time in the logs.
Other things that involve remote data-collection have the same issue. At the very least, you need to have all your computers set so that they're accurate to some factor that's less than the time between data collections. While "data collection" sounds esoteric, it could be something as simple as sending emails from one computer to another, or combining two stacks of digital photos taken from some webcams (if they're portables, that's a separate ball of wax).
Now, do most of these things require all of the computers in your home network to be individually pinging a Level 2 timeserver? No. It would work just as well to have your gateway router get the time from a timeserver, and then offer NTP broadcasts to your network, so that everything could just synchronize itself. You'd have high precision local time, for synchronization, and reasonable accuracy time to a national standard. But that's beyond most users, so most OSes just have each workstation take care of things on its own.
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Unless you're on a slow link (dial-up) with a saturated downlink (i.e. downloading something) and a mostly idle uplink (ASK-s only).
I found that client-to-server time was roughly constant, 150-250ms. server-to-client was about the same of an idle link, up to 6 seconds(!) when downloading stuff.
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The NTP protocol is designed to deal with latency
Re:huh? (Score:5, Informative)
Mod parent up so volunteers won't be scared off (Score:2)
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Yes and no. Besides the jerks who hammer servers, the bandwidth problem is one of accumulation. Even if you're in the DNS rotation for 15 minutes, you'll pick up clients, and those clients may not go away anytime soon. When I left the pool a few years ago, I didn't shut down the server right away, and found that two months after my IP was no longer in rotation, I was still getting tr
Free GPS time equipment! (Score:4, Informative)
Re:Free GPS time equipment! (Score:4, Interesting)
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There must be a joke hidden in this sentence somewhere...
didnt they think of this? (Score:2)
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The vendor program [ntp.org] is one way we're trying to get more control, but all else being equal - more servers helps.
More NTP servers, Lower Quality? (Score:2)
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If they got any worse they would get the date wrong every other day.
Not so much the chips, but the timebase crystals.. (Score:5, Informative)
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.
Re:Not so much the chips, but the timebase crystal (Score:3, Interesting)
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Obviously, youve not had much experience with the quality of the time function in a PC. Having an external, centralized location was the solution to deal with the already sup-par performace of local PC timekeeping.
Personally, Ive used a nice product called TrueTime WinSync [truetime.com] on my windows PC's for quite some time now, and its always the first thing I install after the yearly HD wipes.
There are many, many applications that are adversely affected when 2 PC's on a network do not have an accurate time. Some h
Better way To Do This (Score:5, Interesting)
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.
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Yes - it'd be great if more ISPs offered time keeping services.
One of the plans for the pool is to let ISPs sign up their address space and tell where their NTP servers are. Then when a user using the pool asks for time servers we can point them to the local servers (if they are keeping proper time, etc etc). But it's a bit down the todo list, mostly due to lack of interests from ISPs.
- ask
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Re:Better way To Do This (Score:4, Informative)
All organizations interested in possibly hosting a NIST Internet Time Service server are invited to contact Time and Frequency Division Chief Thomas O'Brian for more information, including a description of the equipment that the organization must have available and a discussion of the other technical qualifications necessary to host a server: obrian@boulder.nist.gov .
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Re:Better way To Do This (Score:5, Interesting)
You are absolutely correct that if network carriers provided NTP services properly on their nets, then the pool wouldn't be necessary. If you go through Usenet archives you can read the history and discussion behind the creation of the pool. Everyone realizes that the pool is an inferior solution that we are stuck with because the network access service providers won't do their job.
The next time I've got a free two hours for self-torture, I'll call Verizon Business customer support and ask them about NTP service. (It will take that long to be transfered to someone who understands the question.)
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Poisoning DNS is never a good idea for public (including ISP) use. Please don't suggest this.
A far better method is to use DHCP to assign one or more local NTP servers, just as is done for DNS servers and other things which may vary from network to network.
DHCP, as a protocol, supports this usage just fine. Various DHCP client implementations also support this by default[1].
All that needs to happen is for the ISP to actually run ntpd (which is trivial), and configure the DHCP server to star
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Akamai does something weird that allows them to spread their subscribers' sites over a variety of networks that may or may not qualify as DNS poisoning, I suppose I could come up with something better based off their ideas. I've never looked into how the nitty gritty of their service works (we were already using it successfully when I came on board), but customers
Re:Better way To Do This (Score:4, Informative)
Unlike a partnership with Akamai, there's no compelling monetary reason for an ISP to offer their own NTP server. Therefore, the easiest (least costly) solution -- at the ISP end -- is probably the most likely to win. Adding a line to dhcpd.conf is probably easier than configuring BIND to issue lies.
And while not everyone uses DHCP, they certainly have some mechanism for communicating things like DNS server addresses, default gateways, and so on. Using that same mechanism (be it DHCP, bootp, or snail mail) to inform the customer of the local NTP server seems trivial in every instance I can think of.
Clients that don't care will obviously ignore this data, but customers who do care can modify their client software accordingly.
Eventually (as in, within the MTBF of a Linksys router), if it ever gains any foothold, clients will use this data by default.
But I guess the most glaring problem to me is that, surprisingly often, the ISP's own DNS servers are slow and/or broken, and overridden. Much of Roadrunner's network is, for instance, assigned DNS servers which are so slow that when browsing the web, more time is spent on simple DNS lookups than on downloading and rendering content.
This, in turn, causes people like me to use a different DNS server on a different network. In my case, I use Level3's DNS at 4.2.2.1 because it is easy to remember and quite fast. Your suggestion ties together DNS and NTP inextricably, such that I'd also be using L3's NTP server by default, when all I really wanted was different DNS.
I don't want a solution to one network problem to have cascading effects on other network services. There's enough of that in the world already.
Remember, the whole point of this is to eliminate end-user manual NTP client configuration, and reduce network load, while offering the useful service of providing accurate time. And I can only hope that, after all of this, network-attached devices of all types will use this mechanism (whatever it is) to automatically derive time from a nearby NTP server.
Some of these devices will be reconfigurable to use whatever NTP server the user wants (certainly, my Linux box is), but hopefully some simpler devices will not be (think print server, networked DVR, WiFi LCD picture frame, or other minimally-configured box).
If a standard method for propogating NTP server names to end-users ever does get implemented, I shouldn't have to run a local copy of BIND and my own regimine of poison, just to allow independant settings for both DNS and NTP servers.
But that's all just my opinion. It is probably wrong.
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Unlike a partnership with Akamai, there's no compelling monetary reason for an ISP to offer their own NTP server. Therefore, the easiest (least costly) solution -- at the ISP end -- is probably the most likely to win. Adding a line to dhcpd.conf is probably easier than configuring BIND to issue lies.
Actually, having some local source of consistent time is pretty much a no brainer on any network that wants logs to be sane, NFS to work correctly, or has any services that require more than one server to run. I really don't mind running them, and letting my customers know. Oh, customer computers that have an accurate clock are far less likely to be obnoxious as all hell when they get email from the future, or way in the past. No, I am not kidding, time.microsoft.com is a good thing in that it got rid of o
GPS time with OpenBSD (Score:5, Informative)
Re:GPS time with OpenBSD (Score:5, Informative)
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Re:GPS time with OpenBSD (Score:5, Informative)
Under OpenBSD I've gotten much more stable timekeeping by recompiling the generic kernel with only one simple change. I set the processor type to 586 or 686 as the case may be. Specifically in the
How about semi-dynamic IPs (Score:2)
A more practical solution... (Score:2)
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Seriously. Put a daemon on all linksys/netgear/etc routers and have them log their own ip addresses for a while. If they stay static for a fairly lengthy amount of time, they sign into a dyndns.org-like server for a few hours a day, and become part of the pool for a while. Maybe have it dependent on their serial numbers or something.
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atomic clock to PC connection? (Score:3, Interesting)
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Of course they do. Anyone who has ever setup ntpd should know that quite well. The default/example config file is STREWN with examples of using hardware clocks... So much so it's difficult to figure out how to set it up to sync to other servers via the network.
From the man page:
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We bought one from these guys. (Score:3, Informative)
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.
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zero config and NTP? (Score:2)
I am sure that there are many private networks where computers are still connecting to external time servers, when the could easily use a server on the local network.
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Zero-config? Hell, they could start by fixing the documentation and user interface. Last time I checked they had no normal man pages, and the diagnostics included things like bit fields expressed in hex ("... kernel time discipline 2001" versus "2041", WTF?)
But I realize it's a complex topic.
My thought is (Score:2, Interesting)
Windows XP's default time servers. (Score:2)
Windows Time (Score:3, Informative)
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2 + 2 = 5 (Score:2)
This doesn't add up. If it doesn't burden existing machines, then why do we need more of them?
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http://www.pool.ntp.org/join.html [ntp.org]
Currently most servers get about 5-15 NTP packets per second with spikes a couple of times a day of 60-120 packets per second. This is roughly equivalent to 10-15Kbit/sec with spikes of 50-120Kbit/sec. The project steadily acquires more timeservers, so the load should not increase dramatically for each server. In plain terms, you probably need at least 384Kbit bandwidth (in and out-going). Since late 2006 the load for most servers have been going up steadily, so we really really need your help! Right now (September 2007) if you are close to the minimum requirements you will get more traffic than you'd like, but we are working on a solution to be deployed over the next month or two.
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Not really. The more time sources you have, the more precise your estimate of the time will be, since you'll be able to cancel out disparate network jitter better.
--JoeRe:load (Score:5, Informative)
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.
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I just want to add a "me, too". Collecting the stats and usage reports for my contribution to the pool takes far more resources than actually contributing to the pool. NTP is really light weight. The only "problem" I've seen is that every couple of months, it is useful for me to reset the state of my firewall. I didn't have to do that before joining the pool.
What can happen if a server gets "overloaded" is that the NTP service degrades. NTP sends UDP packets and so if the NTP server has more than i
Re:load (Score:5, Funny)
Isn't that a bit extreme? Should I maybe waterproof it first?
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VMWare? (Score:2)
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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 ti
clarify please (Score:2)
Could you clarify that a little more please? Why does getting a static IP remove the option of TV service? I cant see any technical problems for that to be the case, so it must be some oddly written contract.
I would imagine with some deep digging, such a contract would be found to be anti-competitive.
On a side note, its pretty obvious why the state of broadband in the US is what it is. TeleVision is the sacred (cash) cow. Combine this with the strong opposition to any sort of NetNeutrality, and the game
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NTP abuse [wikipedia.org]
Re:NTP Isn't Accurate (Score:5, Informative)
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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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.
Eat more manpages. (Score:2)
Re:NTP Isn't Accurate (Score:5, Informative)
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).
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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/ [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
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Dunno about Comcast - but Cox is stable (Score:2)
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If people are using DNS to look up NTP servers like they should be, instead of stupidly using IP addresses, then a dynamic address that changes even as often as every few days will be more than adequate.
Just get yourself a free static subdomain at a place like dyndns.org or zoneedit, and roll with it. A brief interruption due to a switch in IP addresses would likely never even be noticed by ntpd, but even if it were, there's plenty of redundancy in the NTP pool to cover the gap while
Re:how to get ntpd to stop listening on all interf (Score:2)
Anyone know how to get ntpd to stop listening on all interfaces?
Use OpenNTPd [openntpd.org]! No seriously, there's a bug on ntpd's bugzilla [ntp.org] asking for this that has been opened in 2003 and it's still not fixed. ntpd is so badly written that no one dares to write a patch.
And people wonder why I hate every program written by ISC...
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Re:Why not make it peer-to-peer (Score:4, Insightful)
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.
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An NTP server running on a Windows platform already is significantly worse than one on Unix/Linux, and I think that should not be further degraded by running it in a virtual machine.
Remember you want to put the current local time down to nanoseconds in the reply packet. Your underlying platform should be capable of providing that time, and the processing code should not take so long that the time value is completely m