On Thursday, January 17, 2008, we will have a scheduled downtime from 4:00am to 8:00am EST.

Scheduled work includes:

• Upgrading virtual host web server to PHP5 (specifically, version 5.2.5)
• Install new LDAP server hardware and software
• Update the SSH server software

Why is it happening:

• The virtual host web server (virtweb) hosts websites that have URLs of the form http://[projectname].cs.princeton.edu. This server is currently running PHP4 (specifically, version 4.4.7). Because PHP4 reached its end-of-life on 12/31/07 and because there are users in the department who need PHP5, we are upgrading to version 5.2.5. For the most part, PHP code that runs on version 4 will run without change on version 5. We are contacting the owners of those project web pages that use PHP with additional information to ensure a smooth transition.
• In the not-to-distant future, we will also transition the web server that handles user home pages to PHP5. As part of this downtime, we will create a virtual host (running PHP5) that will serve the content of user public_html directories. This host will only be reachable from within the department\’s local network to let users test their home pages under PHP5 via http://web1.cs.princeton.edu/~username
• Note that user home pages will continue to be available (under PHP4) both inside and outside the department as http://www.cs.princeton.edu/~username. We have no plans to change this convention.

On Tuesday, December 4, 2007, we will have a scheduled downtime from 4:00am to 8:00am EST.

Scheduled work includes:

• Switch replacement and patching
• Database server configuration update

On Tuesday, October 30, 2007, we will have a scheduled downtime from 4:00am to 8:00am EDT. Please note that this partially overlaps an OIT-scheduled interruption of all campus networking services from 7:00am to 9:00am EDT. For details on the OIT maintenance, see their posting.

Our scheduled work will primarily consist of operating system patches for the servers in the main machine room (218).

As previously announced, we will have a scheduled downtime on Tuesday, August 21, 2007, from 4:00am to 8:00am EDT. Note that this overlaps OIT\’s scheduled campus-wide interruption of all networking services from 5:00am to 7:00am EDT. See their posting for details.

In response to the file server problem we have been working on since Tuesday, a vendor field engineer will be coming out tonight to help troubleshoot and diagnose the problem. He is expected to arrive around 20:00 (8:00 PM) tonight, Thursday night.

It is very likely that downtime of the server will be required while the engineer is here. This will mean that all services provided by CS Staff, including public cycle servers, clusters, email service, web service, DNS, etc. will be shutdown, as they all depend on the file server. Please make sure to regularly save any data you are working on to protect against losing data when services are shutdown.

We appreciate your patience throughout these last few days, and apologize for any inconvenience.

Update 2007/07/13 @ 03:20 After over 7 grueling hours of emergency downtime and troubleshooting, the network and systems are again up and running, and initial signs look good. While we hesitate to declare victory, we would ask that you please report any instability you notice with as much detail as possible about what you were doing and what failed.

We thank you again for your patience, especially those of you working toward deadlines. If we have indeed licked this issue, look forward to some exciting announcements in the coming weeks.

Our systems are still not playing nice with each other after the installation of a new file server. To get everything in a known state, we must initiate a full shutdown/startup of the equipment in 218 at 8:45am this morning. We don\’t necessarily expect this to fix everything, but it will eliminate many variables. Thank you for your patience.

Update @ 13:45: We are continuing to experience unstable NFS performance, especially on the public linux servers. The public solaris machines (shades), while also affected, appear to be more usable under these conditions. We are working with vendor support to isolate the issue or issues. Further updates will appear on this site as they become available.

Update 7/12 @ 12:15: Problems continue. We are working with our vendor to determine if this is a software or hardware issue.

During our downtime this morning we replaced our aging file server. Despite our efforts, the linux cycle servers are not reliably maintaining their connection. We are re-booting the file server to (hopefully) bring things to a good state. This reboot will impact all our systems for 10 minutes or so. We apologize for the inconvenience.

Here is the scheduled maintenance schedule for the summer:

During these times we will be performing a variety of update, installation, and maintenance tasks.

On Tuesday, May 1, 2007, we will have a scheduled downtime from 6:00am to 8:00am EDT.

Scheduled work includes:

• Database server maintenance

On Tuesday, April 17, 2007, we will have a scheduled downtime from 4:00am to 8:00am EDT.

Scheduled work includes:

• Firmware upgrades on our disk arrays

This work will bring our infrastructure up-to-date with current software and firmware. Among other things, the firmware updates applied to the disk arrays during the last downtime will be freshened to correct some remaining issues.