touch-packages team mailing list archive

[Scott Moser <smoser@xxxxxxxxxx>]

this particular system (in azure) has io that rivals that of floppy disks, so the times are more dramatic.
you're correct in that the information is cached, and that is in general a good thing, but if I ssh to a system only once a day, then every time i do it, i hit this penalty.

thats in addition to the fact that often times the only reason anyone
would ever ssh to a system is to to investigate failure/load issues.
And in that case, i've massively added to the load by ssh'ing in :(.

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https://bugs.launchpad.net/bugs/1426023

Title:
  apt-check should not be run from update-motd

Status in openssh package in Ubuntu:
  New
Status in update-notifier package in Ubuntu:
  New

Bug description:
  If i launch a new cloud instance, and then ssh to it, my ssh login
  blocks, stopping me from doing useful work while '/usr/lib/update-
  notifier/apt-check' runs.

  By far, the biggest offender of this slow login is /usr/lib/update-notifier/apt-check.
  To demonstrate, a fresh cloud instance on azure.

  ## ssh to the instance and run a non-interactive command:
  $ time ssh $cloudhost /bin/true
  real	0m5.066s
  user	0m0.045s
  sys	0m0.004s

  ## ssh in and disable updates-available so it wont run at all
  $ ssh $cloudhost sudo chmod -x /etc/update-motd.d/90-updates-available
  $ time ssh $cloudhost /bin/true
  real	0m2.459s
  user	0m0.026s
  sys	0m0.015s

  ## so disabling that bought us 2.5 seconds back.

  ## How about entirely disabling update-motd
  $ ssh $cloudhost "sudo cp /etc/pam.d/sshd /etc/pam.d/sshd.dist"
  $ ssh $cloudhost "sudo sed -i '/^[^#].*pam_motd/s/^/#/' /etc/pam.d/sshd"
  $ time ssh $cloudhost /bin/true
  real  0m0.650s
  user  0m0.041s
  sys   0m0.004s

  Note, that these things happen even for non-interactive logins, where
  the message of the day is completely swallowed.  Automation tools
  suffer this ever time they ssh to a ubuntu system.

  ProblemType: Bug
  DistroRelease: Ubuntu 14.10
  Package: update-notifier-common 3.157
  ProcVersionSignature: User Name 3.16.0-30.40-generic 3.16.7-ckt3
  Uname: Linux 3.16.0-30-generic x86_64
  ApportVersion: 2.14.7-0ubuntu8.2
  Architecture: amd64
  Date: Thu Feb 26 16:27:02 2015
  PackageArchitecture: all
  ProcEnviron:
   TERM=xterm
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SourcePackage: update-notifier
  UpgradeStatus: No upgrade log present (probably fresh install)

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