This bug is missing log files that will aid in diagnosing the problem.
While running an Ubuntu kernel (not a mainline or third-party kernel)
please enter the following command in a terminal window:
apport-collect 1739672
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable
to run this command, please add a comment stating that fact and change
the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the
Ubuntu Kernel Team.
** Changed in: linux (Ubuntu)
Status: New => Incomplete
** Tags added: xenial
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1739672
Title:
Regression in getaddrinfo(): calls block for much longer on Bionic
(compared to Xenial)
Status in glibc package in Ubuntu:
New
Status in linux package in Ubuntu:
Incomplete
Status in systemd package in Ubuntu:
New
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
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
