We’ll be taking advantage of the continued holiday lull and performing scheduled maintenance tonight from 7:00pm to 11:00pm PST. The following changes will take place:

7:00pm PST (0300 UTC) duration 1 hour: Firmware upgrade. We’ll be upgrading the firmware of the machine that hosts tinderbox.mozilla.org and bonsai.mozilla.org.
8:00pm PST (0400 UTC) duration 3 hours: RHEL5 upgrades. [...]