Analysis has spotted 91-release-upgrade as the most likely expensive remainder. pam_motd enabled, but disabled: - 50-landscape-sysinfo - 91-release-upgrade - 95-hwe-eol disabled
Bionic real 0m18.669s us sy id wa st 22 23 55 0 0 Focal real 0m23.821s us sy id wa st 40 39 21 0 0 Jammy real 0m19.616s us sy id wa st 33 30 37 0 0 This is pretty close to "no-motd" and has no single spike left. The next ones I found in the list are now low and already use caching. The improvement for those would be a (slower and more complex) modification to pam_motd to detect and skip on non-interactive sessions. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to pam in Ubuntu. https://bugs.launchpad.net/bugs/1893716 Title: scripts in /etc/update-motd.d/ run even on login via non-interactive scp and sftp sessions Status in pam package in Ubuntu: Confirmed Status in update-motd package in Ubuntu: Confirmed Bug description: My client has 200+ devices automatically uploading information via sftp and scp to a server every few minutes. After a recent update, I noticed the load on their server spiking through the roof. Upon investigation, I discovered a horde of landscape-sysinfo and /usr/bin/lsb_release processes running that correlated with login session notifications in /var/log/syslog and the load spikes. It appears that even in non-interactive sessions where this information will never be seen, the configuration options below in /etc/pam.d/sshd cause these items to be launched (in fact, probably everything in /etc/update-motd.d). This only started on the system in question after a recent set of system updates were installed. The content of /etc/update-motd.d/* really, really, really shouldn't be executed if the session in question is not interactive, as it provides no value at all. Unfortunately, to disable it for these non- interactive sessions, we also have to disable it for the interactive ones as well where it has some value (though not enough to make spiking the load on this server through the roof an acceptable tradeoff). # Print the message of the day upon successful login. # This includes a dynamically generated part from /run/motd.dynamic # and a static (admin-editable) part from /etc/motd. #session optional pam_motd.so motd=/run/motd.dynamic #session optional pam_motd.so noupdate Also, looking at the script 00-header in /etc/update-motd.d/, /usr/bin/lsb_release is being improperly launched, as /etc/lsb_release does include the necessary information: [ -r /etc/lsb-release ] && . /etc/lsb-release if [ -z "$DISTRIB_DESCRIPTION" ] && [ -x /usr/bin/lsb_release ]; then # Fall back to using the very slow lsb_release utility DISTRIB_DESCRIPTION=$(lsb_release -s -d) fi # cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.7 LTS" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pam/+bug/1893716/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp