NTP's Fate Hinges On "Father Time"

Esther Schindler writes In April, one of the open source code movement's first and biggest success stories, the Network Time Protocol, will reach a decision point, writes Charlie Babcock. At 30 years old, will NTP continue as the preeminent time synchronization system for Macs, Windows, and Linux computers and most servers on networks? Or will this protocol go into a decline marked by drastically slowed development, fewer bug fixes, and greater security risks for the computers that use it? The question hinges to a surprising degree on the personal finances of a 59-year-old technologist in Talent, Ore., named Harlan Stenn.

Comments

Re:Fewer bug fixes?

[BitZtream]

NTP doesn't just 'return a string of numbers'.

But either way, the article isn't about NTP the protocol, its about one shitty implementation of NTP that I don't think anyone even uses anymore. Windows and OS X certainly don't.

The summary and headline are equivalent to saying 'Netscape is going out of business, HTTP in danger of disappearing'

If he were to drop dead right this instant ... no one that matters would notice beyond his family.

Re:Not only finances are an issue

[Anonymous Coward]

And at the Google Summer of Code summits I've seen the NTP devs (I can't say if it was him or not) stand up in front of a couple hundred FOSS project leaders begging for help with their bus factor problem.

This sort of infrastructure code is at once niche, genuinely hard work, demanding the highest quality programming skill, unrewarded, non-sexy,
and vitally important to the world.

I am one of the ntpd maintainers

[Terje Mathisen]

I've been on the "NTP Hackers" mailing list for ~15 years now, my last major effort was to develop a server-optimized multi-threaded version of the core ntpd sw: I was hoping for wire speed packet processing on an embedded linux platform, but had to settle for 3-500 Mbit/s since the target kernel version did not support multi-thread targeting of incoming packets, i.e. I needed to have a single receive thread which would fetch the incoming packets, timestamp them and queue them up, then all the other threads/cores would grab them from there.

Back to the "why are there bugs in such a trivial protocol?" question:

By far the biggest cause of required effort when trying to modify or optimize the NTPD distribution is the need to support a big number of OSs and even larger number of OS versions, some of them more than 20 years old, even if the main targets are Unix-like or Windows.

The second problem is the need to support 30+ reference clocks, with all sorts of OS/version specific interfaces needed in order to timestamp events as accurately as possible.

The third and final major stumbling block is all the crypto stuff, which got added in order to be able to authenticate both time packets and monitoring/configuration requests, and this is where the latest major bugs have been found.

PHK (who is working on Ntimed) has spent a lot of time on NTP, including his time as a core FreeBSD hacker when he made sure that the FBSD had the best possible timekeeping kernel. This is the reason that my personal pool server has always used FreeBSD.

If your only need is to get 0.1s level time sync on a number of client only machines, then it really doesn't matter how you implement the NTP protocol, except that you should really try to measure and adjust the local clock frequency so as to track the reference time!

The default Windows time code implements Simple NTP (SNTP) which uses the NTP packet format but doesn't try to implement the proper control loop to steer the local clock, instead it just yanks the OS clock resulting in a sawtooth-like pattern of clock offsets.

Terje