Is Orion configured for high availability under the Acropolis service?

The Acropolis core and premium hosting service tiers use a single Orion server instance. To date, ever since Acropolis was launched in early 2007, unscheduled Orion server downtime under Acropolis has been exceedingly rare and has never lasted more than an hour. Scheduled downtime has occurred less than a few times a year, primarily for the purpose of upgrading the Orion server software version, and has never lasted more than 15 minutes on a weekend. You can expect an uptime of at least 99.84%, corresponding to a maximum down time of 1 hr per month.

That being said, Orion is capable of being configured for failover, although we have not found a reason to do so. Configuration for failover is however an option under the Acropolis dedicated hosting service tier.