OCS Providers File - High Numbers of Requests

[Ben Cooksley]

On Sat, Sep 25, 2021 at 12:34 AM Aleix Pol <aleixpol at kde.org> wrote:

> On Fri, Sep 24, 2021 at 1:32 AM Nicolás Alvarez
> <nicolas.alvarez at gmail.com> wrote:
> >
> > El jue, 23 de sep. de 2021 a la(s) 19:31, Aleix Pol (aleixpol at kde.org)
> escribió:
> > >
> > > On Thu, Sep 23, 2021 at 10:12 PM Nicolás Alvarez
> > > <nicolas.alvarez at gmail.com> wrote:
> > > >
> > > > El jue, 23 de sep. de 2021 a la(s) 08:55, Aleix Pol (
> aleixpol at kde.org) escribió:
> > > > >
> > > > > On Thu, Sep 23, 2021 at 11:52 AM Ben Cooksley <bcooksley at kde.org>
> wrote:
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > It has recently come to our attention that the number of queries
> being handled for the endpoint
> https://autoconfig.kde.org/ocs/providers.xml on a day to day basis has
> gotten to the point where it is causing issues with server responsiveness
> to other traffic. This is perhaps best summarised by the following:
> > > > > >
> > > > > > root at nicoda /var/log/apache2 # ls -lah ...
> > > > > > -rw-r----- 1 root adm 458M Sep 23 06:25 autoconfig.kde.org.log.1
> > > > > > -rw-r----- 1 root adm 381M Sep 23 06:25
> networkcheck.kde.org.log.1
> > > > > > -rw-r----- 1 root adm 143M Sep 23 06:25 www.kde.org.log.1
> > > > > >
> > > > > > root at nicoda /var/log/apache2 # cat autoconfig.kde.org.log.1 |
> wc -l
> > > > > > 4,222,343
> > > > > >
> > > > > > Based on those numbers we're looking at 48-49 requests per
> second (on average - peaks are much higher by many magnitudes), which seems
> extremely excessive given that this file is only supposed to be retrieved
> by KDE software when GHNS functionality is triggered. That is supported by
> the substantial size difference it has over networkcheck.kde.org - which
> is used by plasma-nm and NetworkManager (on Neon) to check for whether they
> have a working internet connection - which i'd expect to be the site
> receiving the most traffic.
> > > > > >
> > > > > > As such, I therefore suspect we have bug(s) in software that
> makes use of GHNS functionality.
> > > > > >
> > > > > > It would therefore be appreciated if we could please review the
> software in question to determine whether it is operating correctly. Given
> that it usually runs in the background on user systems, i'd especially
> appreciate it if a detailed review could be conducted on Discover and other
> software that conducts package management operations or assists in managing
> updates.
> > > > > >
> > > > > > Unfortunately all these applications submit a fairly useless
> user agent (Mozilla/5.0) so it is impossible for Sysadmin to ascertain any
> further information. If we could get information on the software that is
> originating the request added to the user agent to assist in investigating
> these issues in the future that would be extremely helpful.
> > > > > >
> > > > > > Thanks,
> > > > > > Ben
> > > > >
> > > > > That's correct. Discover fetches them at startup. It's necessary
> to be
> > > > > able to check if there are updates on KNS-provided resources.
> > > > >
> > > > > Incidentally,  I was looking into this yesterday incidentally. We
> > > > > could see if caching is broken somehow. A request will still be
> needed
> > > > > though to check if the cache is out of date.
> > > >
> > > > Caching seems to be working, since the vast majority of the requests
> > > > are returning 304 Not Modified.
> > > >
> > > > However in *many* cases I see a single IP making multiple requests in
> > > > the same second, and doing it again the next minute. Here's one IP
> > > > address picked randomly:
> > > >
> > > > [22/Sep/2021:06:25:41 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:25:41 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:25:41 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:25:41 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:27:57 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:27:58 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:27:58 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:32 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:32 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:32 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:32 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:59 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:59 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:59 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:28:59 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:30:11 +0000] "GET /ocs/providers.xml HTTP/1.1" 200
> > > > [22/Sep/2021:06:30:11 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:30:11 +0000] "GET /ocs/providers.xml HTTP/1.1" 200
> > > > [22/Sep/2021:06:30:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:30:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:30:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:30:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:19 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:19 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:19 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:19 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > > [22/Sep/2021:06:31:38 +0000] "GET /ocs/providers.xml HTTP/1.1" 304
> > > >
> > > > This continues for hours. And it's not an isolated case; again, the
> IP
> > > > I searched for was a random one from the log.
> > > >
> > > > There are 120 IP addresses that *each* made more than 10,000 requests
> > > > in a 24h period.
> > > >
> > > > I tried a few GHNS things on my own system and I couldn't reproduce
> it...
> > > >
> > > > --
> > > > Nicolás
> > >
> > > Is there a possibilty that we can get an UserAgent of something like
> > > that to see who's asking?
> >
> > Yes please :P
> >
> > (all requests to this file currently have "Mozilla/5.0" as the
> > User-Agent, I very much welcome modifying the code so that it sends
> > something useful instead)
> >
> > --
> > Nicolás
>
> This is for KNS:
> https://invent.kde.org/frameworks/knewstuff/-/merge_requests/142
>
> Attica already sets the UserAgent.
>

Thanks for getting all of these changes through.
Hopefully in the coming months we'll start to see the impact of these
changes.

In the meantime, we've switched autoconfig.kde.org to our CDN provider,
which should enable our systems to continue to handle the current load
we're experiencing.


> Aleix
>

Cheers,
Ben
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