nanog mailing list archives
Re: Recent NTP pool traffic increase
From: Yury Shefer <shefys () gmail com>
Date: Wed, 21 Dec 2016 05:04:35 +0000
Google announced public NTP service some time ago: https://developers.google.com/time/ On Tue, Dec 20, 2016 at 7:29 PM Laurent Dumont <admin () coldnorthadmin com> wrote:
I do think that the point of the Pool network is to be used by both consumers and vendors. And as mentioned before, there is a process if you are a vendor and want to use the pool within a commercial product. I have 3 NTP servers running and I don't really care who is using it. That said, setting up your own infrastructure is also worth considering if it's a business critical feature. I assume that a Snapchat app that fails to have accurate time or correct itself could be abused. To be honest, the fact that NTP is still something managed by volunteers and not a regulated entity (a bit like DNS) is mind boggling. On 12/20/2016 09:41 PM, Keenan Tims wrote:Better for whom? I'm sure all mobile operating systems provide someaccess to time, with a least 'seconds' resolution. If an app deemsthis time source untrustworthy for some reason, I don't think thereasonable response is to make independent time requests from avolunteer-operated pool for public servers designed for hostsynchronization. Particularly on mobile, the compartmentalization ofapplications means that this 'better' time will only be accessible toone application, and many applications may have this 'better time'requirement. These developers should be lobbying Apple and Google forbetter time, if they need it, not making many millions of calls to theNTP pool. To make things worse, I'm fairly sure that Apple's 'nobackground tasks' policy means that an application can't *maintain*its sense of time, so it would not surprise me if it fires off NTPrequests every time it is focused, further compounding the burden.Time is already available, and having every application query for itsown time against a public resource doesn't seem very friendly. Itcertainly doesn't scale. If they are unsuccessful lobbying the OS, whynot trust the time provided by the API calls they are surely doing totheir own servers? Most HTTP responses include a timestamp; surelythis is good enough for expiring Snaps. Or at least operate their ownNTP infrastructure.I'm sure that Snap had no malicious intent and commend them for theirquick and appropriate response once the issue was identified, but Idon't think this behaviour is very defensible. I for one was notharmed by the ~10x increase in load and traffic on my NTP pool node,but the 100x increase if a handful of similar apps decided they 'need'more accurate time than the OS provides would be cause for concern,and I suspect a great many pool nodes would simply disappear,compounding the problem. Please make use of these and similar servicesas they are designed to be used, and as efficiently as possible,especially if you are responsible for millions of users / machines.In a similar vein, I've always been curious what the ratio Google seesof ICMP echo vs. DNS traffic to 8.8.8.8 is...KeenanOn 2016-12-20 18:16, Tim Raphael wrote:Exactly,Also they’re across Android and iOS and getting parity of operationsacross those two OSs isn’t easy.Better to just embed what they need inside the app if it isspecialised enough.- TimOn 21 Dec. 2016, at 10:13 am, Emille Blanc<emille () abccommunications com> wrote:Perhaps the host OS' to which snapchat caters, don't all have adevent ntp subststem available?I have vague recollections of some other software (I'm sure we allknow which) implemented it's own malloc layer for every system itran on, for less trivial reasons. ;)________________________________________From: NANOG [nanog-bounces () nanog org] On Behalf Of Tim Raphael[raphael.timothy () gmail com]Sent: Tuesday, December 20, 2016 5:34 PMTo: Gary E. MillerCc: nanog () nanog orgSubject: Re: Recent NTP pool traffic increaseThis was my thought actually, Apple does offer some time services aspart of the OS but it’s becoming common with larger / more popularapps to provide some of these services internally.Look at the FB app for example, there are a lot of “system” thingsthey do themselves due to the ability to control specifics. Usersdon’t want to have to install a second “specialised app” for thiseither.With regard to an ephemeral chat app requiring time sync, I canthink of quite a few use cases and mechanisms in the app that mightrequire time services.- TimOn 21 Dec. 2016, at 9:26 am, Gary E. Miller <gem () rellim com> wrote:Yo Valdis.Kletnieks () vt edu!On Tue, 20 Dec 2016 20:20:48 -0500Valdis.Kletnieks () vt edu wrote:On Tue, 20 Dec 2016 18:11:11 -0500, Peter Beckman said:Mostly out of curiosity, what was the reason for the change in theSnapchat code, and what plans does Snap have for whatever reasonthe NTP change was put in place?From other comments in the thread, it sounds like the app was simplylinked against a broken version of a library....But why is a chat app doing NTP at all? it should rely on the OS, ora specialized app, to keep local time accurate.RGDSGARY---------------------------------------------------------------------------Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703gem () rellim com Tel:+1 541 382 8588
Current thread:
- Re: Recent NTP pool traffic increase, (continued)
- Re: Recent NTP pool traffic increase Harlan Stenn (Dec 22)
- Re: Recent NTP pool traffic increase Laurent Dumont (Dec 22)
- Re: Recent NTP pool traffic increase Philip Homburg (Dec 23)
- Re: Recent NTP pool traffic increase Majdi S. Abbas (Dec 30)
- Re: Recent NTP pool traffic increase Allan Liska (Dec 30)
- RE: Recent NTP pool traffic increase Emille Blanc (Dec 30)
- RE: Recent NTP pool traffic increase Allan Liska (Dec 30)
- RE: Recent NTP pool traffic increase Jeff McAdams (Dec 30)
- Re: Recent NTP pool traffic increase Harlan Stenn (Dec 30)
- Re: Recent NTP pool traffic increase Majdi S. Abbas (Dec 30)
- Re: Recent NTP pool traffic increase Yury Shefer (Dec 20)
- Re: Recent NTP pool traffic increase Royce Williams (Dec 20)
- Re: Recent NTP pool traffic increase Royce Williams (Dec 20)
- Re: Recent NTP pool traffic increase Harlan Stenn (Dec 20)
- Re: Recent NTP pool traffic increase Rich Kulawiec (Dec 30)
- Re: Recent NTP pool traffic increase Valdis . Kletnieks (Dec 20)
- Re: Recent NTP pool traffic increase Damian Menscher via NANOG (Dec 20)
- Re: Recent NTP pool traffic increase Jad Boutros via NANOG (Dec 20)
- Re: Recent NTP pool traffic increase Paul Gear (Dec 20)
- Re: Recent NTP pool traffic increase Royce Williams (Dec 20)
- Re: Recent NTP pool traffic increase Valdis . Kletnieks (Dec 19)