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News/Toolforge Stretch deprecation

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Revision as of 00:39, 16 February 2022 by imported>Quiddity (→‎See also: add email)
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This page details information about deprecating and removing hosts running Debian Stretch (9.x) as an operating system from the Toolforge infrastructure. The login bastions and Grid execution hosts are still running Stretch and must be replaced with new instances.

What is changing?

  • New bastion hosts running Debian Buster with connectivity to the new job grid
  • New versions of PHP, Python3, and other language runtimes
  • New versions of various support libraries

We are introducing a configuration option to let you select which operating system (Debian Stretch or Debian Buster) you want for your grid-based tool. That way, you can try out the migration from Stretch to Buster at your convenience.

Timeline

  • 2022-02-15: Yes Done (email) Availability of Debian Buster grid announced to community
  • 2022-03-21: Reminders via email to tool maintainers for tools still running on Stretch
  • Week of 2022-04-21:
    • Daily reminders via email to tool maintainers for tools still running on Stretch
    • Switch login.toolforge.org to point to Buster bastion
  • Week of 2022-05-02: Evaluate migration status and formulate plan for final shutdown of Stretch grid
  • Week of 2022-05-21: Shutdown Stretch grid

What should I do?

You should migrate your Toolforge tool to a newer environment. You have two options:

  • migrate from Toolforge Stretch Grid Engine to Toolforge Kubernetes.
  • migrate from Toolforge Stretch Grid Engine to Toolforge Buster Grid Engine.

SSH to the bastions

During the compatibility period, there are 2 sets of bastions available:

  • login.toolforge.org: points to the old Debian Stretch bastion
  • dev.toolforge.org: points to the old Debian Stretch development bastion
  • login-buster.toolforge.org: points to the new Debian Buster bastion
  • dev-buster.toolforge.org: points to the new Debian Buster development bastion

When the time arrives, the old Stretch bastion will stop working, and both login.toolforge.org and dev.toolforge.org will point to Buster bastions.

Move a grid engine webservice

We strongly encourage you to migrate web services to Kubernetes instead of using the grid.

If you have strong reasons to keep using the grid for webservices, then try the --release {buster|stretch} parameter:

:# Connect to the Buster bastion
$ ssh <your-shell-name>@login-buster.toolforge.org

:# Become your tool account
$ become YOUR_TOOL

:# Start the webservice as a Kubernetes container rather than a grid job
:# <type> is one of: php7.2, php5.6, python, python2, nodejs, golang, jdk8, ruby2, tcl
$ webservice --backend=kubernetes --release buster <type> start
:# -- OR --
:# Start the webservice as a Buster grid job
:# <type> is one of: lighttpd, uwsgi-python, tomcat, generic, lighttpd-plain, nodejs, uwsgi-plain
$ webservice --backend=gridengine --release buster <type> start

See Help:Toolforge/Web#Backends for more information on migrating from grid engine to Kubernetes.

Move a continuous job

:# Connect to the Stretch bastion
$ ssh <your-shell-name>@login-buster.toolforge.org
:# Become your tool account
$ become YOUR_TOOL

:# Start your job on the Buster job grid(note: this is a specific example for a php job that checks for a quota).
$ jstart -release buster -mem 350m php check_my_quota.php

The exact commands needed to start each continuous job vary greatly from tool to tool. This would be a great time to make a page of reference material for yourself and other maintainers here on Wikitech in the Tool namespace and using the Tool template if you haven't already.

Move a cron job

To migrate your cron server grid server is the same, adjust the -release jsub argument when creating them with the crontab command.

The grid cron job server is Debian Stretch and will remain that way until the end of the migration, meaning that if you don't specify a -release option, the default (stretch) will be used.

See Executable paths with jsub for other potential problems with cron jobs.

If your workload permits, please avoid scheduling cronjobs from midnight to 3am so you're not competing with other cronjobs for system resources. That time window is currently very crowded.

What are the primary changes with moving to Buster?

Language runtime and library versions

The vast majority of the language runtimes and libraries installed on the grid nodes are upgraded in BUSTER.

Runtime Stretch Version Buster Version
Python3 3.5.3 3.7.3
PHP 7.2 7.3
Python2 2.7.13 2.7.16
NodeJS 8.11.1 10.24.0
Perl 5.24 5.28
Java 11.0.6 11.0.9
Ruby 2.3.3 2.5.5
Mono 5.12.0 5.18.0
TCL 8.6.0 8.6.9
R 3.3.3 3.5.2

Solutions to common problems

Having trouble with the new grid? If the answer to your problem isn't here, ask for help in #wikimedia-cloud connect or file a task in Phabricator using this template.

Executable paths with jsub

Some system executables have changed their path between Debian releases. When scheduling jobs, the jsub command resolves the full path for executable files, which means that a given command may fail if the destination grid is not the same Debian release as the server in which jsub is run.

This happens in particular when running jsub from a Debian Buster bastion host to schedule jobs in the Debian Stretch grid.

The solutions to these problem are simple in most cases:

  • use a wrapper script as entry point for your jobs.
  • schedule a job for a given grid release from a matching Debian release bastion.
  • if possible, use explicit full path when scheduling your jsub jobs.

Example of a problematic jsub operation, in a Debian Buster bastion:

tool.mytool@tools-sgebastion-10:~ $ jsub -N myjob-stretch -release stretch echo hi
Tour job 3595 ("myjob-stretch") has been submitted
tool.mytool@tools-sgebastion-10:~ $ jsub -N myjob-buster -release buster echo hi
Your job 3596 ("myjob-buster") has been submitted
tool.mytool@tools-sgebastion-10:~ $ cat myjob-stretch.*
-bash: /usr/bin/echo: No such file or directory
tool.mytool@tools-sgebastion-10:~ $ cat myjob-buster.*
hi

Example of a good jsub operation, in a Debian Buster bastion:

tool.mytool@tools-sgebastion-10:~ $ jsub -N mywrappedjob-stretch -release stretch ./my-wrapper.sh
Tour job 3596 ("myjob-stretch") has been submitted
tool.mytool@tools-sgebastion-10:~ $ jsub -N myjob-stretch -release stretch /bin/echo hi
Tour job 3597 ("myjob-stretch") has been submitted
tool.mytool@tools-sgebastion-10:~ $ jsub -N myjob-buster -release buster /bin/echo hi
Your job 3598 ("myjob-buster") has been submitted
tool.mytool@tools-sgebastion-10:~ $ cat mywrappedjob-stretch.*
hi
tool.mytool@tools-sgebastion-10:~ $ cat myjob-stretch.*
hi
tool.mytool@tools-sgebastion-10:~ $ cat myjob-buster.*
hi

In case of cron jobs, the problem is the same, with the particularity that our cron server is Debian Stretch, and will stay that way until the end of the migration, when we will introduce a Debian Buster cron server replacement.

Example of a reasonable crontab file (uses either a wrapper or full path):

tool.mytool@tools-sgebastion-10:~ $ crontab -l
10 * * * * /usr/bin/jsub -N cron-10 -once -quiet ./mywrappedjob.sh
12 * * * * /usr/bin/jsub -N cron-11 -once -quiet /bin/echo hello

Example of a bad crontab file (no wrapper, missing full path):

tool.mytool@tools-sgebastion-10:~ $ crontab -l
10 * * * * /usr/bin/jsub -N cron-10 -once -quiet echo hello

Rebuild virtualenv for python users

Since the python executables and libraries are updated in Debian Buster, local virtualenvs will need to be deleted and re-created on the new bastion for anything that runs from those virtualenvs to work. Several errors are likely to be caused by old virtualenvs with one obvious one being an unexpected ImportError.

Using a requirements file may make this simpler in many cases, if your project doesn't already use one. You can create one in your local directory by running pip freeze > requirements.txt in your tool folder with your virtualenv activated. Then later on, you can simply use pip install -r requirements.txt to install the new environment after you deleted the old virtualenv and created a new one. For more information on this option, see pip's documentation on requirements files.

Example 1: Upgrading a Stretch grid engine based tool to the Buster grid

Follow these steps if you manually submit jobs using jsub, or if you submit jobs using a crontab.

$ ssh <your-shell-name>@login-buster.toolforge.org
$ become YOUR_TOOL
$ rm -rf venv     # This will destroy the virtualenv and all libraries, so make sure you know what you will need to install later!
$ virtualenv venv
$ source venv/bin/activate
$ pip install --upgrade pip # upgrade pip itself to avoid problems with older versions
$ pip install ... # Here you'd use the requirements file syntax if you have one, or you'd manually install each needed library.
Example 2: Upgrading a uWSGI webservice into a Kubernetes container

If you are currently running your uWSGI webservice under the Grid Engine backend (i.e., webservice uwsgi-python command), and you want to upgrade to a uWSGI webservice running under Kubernetes (i.e., webservice --backend=kubernetes python command), you should rebuild your virtualenv as follows:

$ ssh <your-shell-name>@login-buster.toolforge.org
$ become YOUR-TOOL
$ webservice --backend=kubernetes python stop
$ webservice --backend=kubernetes python shell # do not skip this step – setting up the venv directly from the bastion may result in serious performance issues, compare T214086
$ rm -rf www/python/venv/ # this will destroy the virtualenv and all libraries, so make sure you know what you will need to install later!
$ python3 -m venv www/python/venv/
$ source www/python/venv/bin/activate
$ pip install --upgrade pip # upgrade pip itself to avoid problems with older versions
$ pip install -r www/python/src/requirements.txt # assuming your tool has a requirements.txt file
$ webservice --backend=kubernetes python start
Example 3: Upgrading a Kubernetes uWSGI webservice

If you are already using the Kubernetes backend, there is nothing you need to do -- the container will use the same image as before.

Delete a tool

Some tools were experiments that are done, others were made obsolete by other tools, some are just things that the original maintainer is tired of caring for. There is no UI with a big red "Delete this tool" button, so how can you responsibly request that a tool be deleted?

You can't delete a tool account yourself, though you can delete the content of your directories and make an existing web tool inaccessible by shutting down the web service (webservice stop). If you really want a tool account to be deleted, please follow the steps described at Toolforge (Tools to be deleted).

SSH to login-buster.toolforge.org fails with 'Permission denied (publickey)'

This is typically an issue with the newer Debian Buster provided version of sshd on the server side refusing to authenticate an insecure or deprecated public key type. Specifically, support for DSA (ssh-dss) keys was deprecated in Openssh 7.0. If your ssh public key starts with the string "ssh-dss" you will be impacted by this. RSA keys smaller than 1024 bits are also deprecated.

First make sure that you are passing a valid key by attempting to ssh to login.toolforge.org using the same public key and username. If this also fails, the problem is likely something other than the ssh key type. Join us in #wikimedia-cloud connect for interactive debugging help.

If you can ssh to login.toolforge.org with no errors, your key is probably of an unsupported type. Generate a new ssh key pair and upload the public key using the form at https://toolsadmin.wikimedia.org/profile/settings/ssh-keys or Special:Preferences#mw-prefsection-openstack. We currently recommend using either ed25519 or 4096-bit RSA keys. See Production shell access#Generating your SSH key for more information.

SSH to login-buster.toolforge.org fails with 'Permission denied (publickey,hostbased)'

In case you face this problem, make sure to use the right shell name located on your User Preferences called **Instance shell account name**. It's supposed to be used in logging into the Toolforge server when need be, whether Stretch or Buster.

Monitoring tools

Why are we doing this?

This is an implementation of our Operating System Upgrade Policy.

In a nutshell, we use Debian and deprecate versions three years after release and remove them completely from our infrastructure by four years after their release.

Debian Stretch was released in June 2017, and long term support for it (including security updates) will cease in June 2022. We need to shut down all Stretch hosts before the end of support date to ensure that Toolforge remains a secure platform. This migration will take several months because many people still use the Stretch hosts and our users are working on tools in their spare time.

See Operating System Upgrade Policy for more information.

See also

Communication and support

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Learn about major near-term plans
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