[downtime] IMPORTANT – Project Web Server Upgrade 2022-08-09

Good morning,

Following up on the below downtime/upgrade announcement, it is important to note that this upgrade will bring a couple of significant changes to our project web server. Specifically, PHP on this server will be upgraded from version 5.6.25 to version 8.0.13, and Phusion Passenger, the system which allows for support of web application frameworks, will be upgraded from version 5.0.30 to version 6.0.14. There are several incompatibility changes between these versions, and some project web sites will need code upgrades/adjustments in order to work properly on the new server. You can read more about the changes between the PHP versions on these pages:


Note that each page has a “Backward Incompatible Changes” link, which is worth reviewing to prepare for your site update.

The most notable change in Passenger is that some configuration can no longer be accomplished in .htaccess files, so must, for security reasons, move to the server config files. The upgraded Passenger also introduced Generic Language Support, or: “the ability to support any and all arbitrary apps”. You can read more about the changes here:


CS Staff is performing a basic review of each project web site on the upgraded web server, and /most/ sites appear to be in good working order. For sites with obvious compatibility issues, we will be reaching out directly to the site owners to advise on expected changes. However, as it is impossible for us to review all possible aspects of your site, we strongly encourage you to review your site after the upgrade on August 9 to ensure it is working as expected, as well as reviewing the PHP changes before the upgrade in order to anticipate changes you may need to make.

Please note that the above changes apply ONLY to the project web sites at this time. Personal (“tilde”) sites, and any other content hosted under “www.cs.princeton.edu”, are not yet affected by this upgrade. If you are concerned that your site may need substantial change and would like to review it using the new web server prior to the upgrade, please reach out to [csstaff@cs.princeton.edu] for assistance in doing so. As always, please also let us know if you have any other questions or concerns.

CS Staff

—– Forwarded Message —–
From: “csstaff”
To: “downtime”
Sent: Tuesday, July 26, 2022 1:32:22 PM
Subject: [downtime] CS Infrastructure Upgrades, Tuesday, August 9, 2022, 05:00-17:00

Date: Tuesday, August 9, 2022 (05:00-17:00)

Who is affected:
All users of the CS Department computing infrastructure.

What is happening:
CS Staff will upgrade the user-accessible servers in our infrastructure,
including cycles, ionic, courselab, armlab, and the project web servers.
The systems will be upgraded to the latest Springdale 8 distribution for
the x86_64 architecture and RockyLinux 8 distribution for the aarch64
architecture (i.e., armlab).

SPECIAL NOTE: As we are reloading the Linux servers, all crontabs will be
deleted. If you have crontabs that you wish to persist, you will need to
back up your crontabs before the downtime and restore them after.

Please note that the downtime window is significantly longer than our usual
windows due to the high-touch nature of OS reinstallations. It is our
intention that the cycles machines and web servers will see the earliest
returns to service. Some parts of the ionic cluster may extend later in the
day. Overall, we expect to finish all of the upgrades earlier than this
window, but the wide time frame acknowledges the uncertainties involved.

Why is it happening:
This is part of the routine maintenance of the publicly-accessible systems
and will bring newer versions of installed tools and software.

We will post updates to the status page: http://www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

CS Staff
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