System Operations will be replacing a failed battery backup unit in one of our customer-facing database servers at 11:00pm PST on Thursday, December 20th, 2012. During this time, MySQL 5.x databases will be unavailable. The work is expected to take no more than 30 minutes.
** Update **
The maintenance window will me moved forward by 1 hour to 11:59pm tonight, December 20th.
** Update **
Database server is back up as of 12:30am.
— Joe (System Operations)