ubuntu@foufoune:~$ lsb_release -rd
Description: Ubuntu 17.10
Release: 17.10
ubuntu@foufoune:~$ apt-cache policy systemd
systemd:
Installed: 234-2ubuntu12.3
Candidate: 234-2ubuntu12.3
Version table:
*** 234-2ubuntu12.3 500
500 http://azure.archive.ubuntu.com/ubuntu artful-updates/main amd64
Packages
100 /var/lib/dpkg/status
234-2ubuntu12.1 500
500 http://security.ubuntu.com/ubuntu artful-security/main amd64
Packages
234-2ubuntu12 500
500 http://azure.archive.ubuntu.com/ubuntu artful/main amd64 Packages
ubuntu@foufoune:~$ time ping __cloud_init_expected_not_found
ping: __cloud_init_expected_not_found: Temporary failure in name resolution
real 0m15.016s
user 0m0.000s
sys 0m0.003s
After applying the workaround from comment #11, I see fast lookups
again.
ubuntu@foufoune:~$ cat /etc/systemd/resolved.conf
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See resolved.conf(5) for details
[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=yes
#MulticastDNS=yes
#DNSSEC=no
#Cache=yes
#DNSStubListener=udp
LLMNR=no
ubuntu@foufoune:~$ time ping __cloud_init_expected_not_found
ping: __cloud_init_expected_not_found: Name or service not known
real 0m0.006s
user 0m0.000s
sys 0m0.001s
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1739672
Title:
Regression in getaddrinfo(): calls block for much longer on Bionic
(compared to Xenial), please disable LLMNR
Status in glibc package in Ubuntu:
Invalid
Status in linux package in Ubuntu:
Invalid
Status in systemd package in Ubuntu:
Fix Released
Status in glibc source package in Artful:
New
Status in linux source package in Artful:
New
Status in systemd source package in Artful:
New
Status in glibc source package in Bionic:
Invalid
Status in linux source package in Bionic:
Invalid
Status in systemd source package in Bionic:
Fix Released
Bug description:
When testing MAAS on Bionic, we noticed sluggish performance that we
could not immediately explain.
After comparing the results from a run of the test suite on Xenial to
a run on Bionic, we determined that the slowdowns had to do with DNS
lookups. In particular, if MAAS attempts to resolve a hostname using
getaddrinfo() and the call fails, on Xenial the negative result is
returned in a fraction of a second. On Bionic, the negative result is
returned in ~1.6 seconds, according to some measures.
### To run the test ###
git clone https://github.com/mpontillo/test-getaddrinfo
cd test-getaddrinfo
make
### Results on Xenial ###
$ time ./test not-a-real-hostname
Trying to resolve: not-a-real-hostname
getaddrinfo errno: Success
getaddrinfo() return value: -2 (Name or service not known)
real 0m0.015s
user 0m0.000s
sys 0m0.000s
### Results on Bionic ###
$ time ./test not-a-real-hostname
Trying to resolve: not-a-real-hostname
getaddrinfo errno: Resource temporarily unavailable
getaddrinfo() return value: -3 (Temporary failure in name resolution)
real 0m1.609s
user 0m0.004s
sys 0m0.000s
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1739672/+subscriptions
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