Discussion:
[akregator] [Bug 401850] New: excessive DNS usage DOS's router
b***@kde.org
2018-12-07 05:45:10 UTC
Permalink
https://bugs.kde.org/show_bug.cgi?id=401850

Bug ID: 401850
Summary: excessive DNS usage DOS's router
Product: akregator
Version: 5.8.3
Platform: Kubuntu Packages
OS: Linux
Status: REPORTED
Severity: major
Priority: NOR
Component: general
Assignee: kdepim-***@kde.org
Reporter: ***@caseyconnor.org
Target Milestone: ---

I have recently experienced intermittent network dropouts. I believe I traced
the issue to Akregator making a large number of DNS queries, but I'm not
qualified to assess that.

I run dd-wrt on an ancient Linksys router. The status page for the router shows
~80 open connections with Firefox running. I start Akregator and the refreshing
of the feeds causes this number to reach 1024 connections in a few seconds
(sometimes I need to do a manual refresh of the feeds to reach this many.)
Inspection of the connections list on the router shows numerous TIME_WAIT
sockets to google IPs (Example IPs: 172.217.3.211 and 216.58.195.83). I use
google nameservers (75.75.75.75) so I conjectured that Akregator is making
numerous DNS calls. 1024 is the "IP Filter Maximum Ports" value for the router,
so the router is rendered unusable until the TIME_WAITs time out.

I'm sure a more modern or differently-configured router could handle this
better, but given that I've used the same feeds and same router for years with
Akregator, it seems like something has changed recently. Also, I have only 103
feeds (~620 unread articles), and it seems odd to use >1000 DNS calls to
refresh those feeds (and pull no new articles in.)

I thus wondered if there is some accidental over-usage of DNS going on, but I
will stop speculating. I don't know if the finger points to Akregator or some
underlying OS issue.

I recently upgraded from 18.04 to 18.10, and the net issues seem to have
started after that, but to be honest I upgraded several weeks ago and only
noticed the net issues in the last week, so I can't be sure of the association.

KDE Plasma Version: 5.13.5
KDE Frameworks Version: 5.50.0
Qt Version: 5.11.1
Linux <hostname> 4.18.0-12-generic #13-Ubuntu SMP Wed Nov 14 15:17:05 UTC 2018
x86_64 x86_64 x86_64 GNU/Linux
--
You are receiving this mail because:
You are the assignee for the bug.
b***@kde.org
2018-12-07 05:45:19 UTC
Permalink
https://bugs.kde.org/show_bug.cgi?id=401850

***@caseyconnor.org changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@caseyconnor.org
--
You are receiving this mail because:
You are the assignee for the bug.
Loading...