announced today some changes to its service level agreement (SLA). First, the SLA will no longer have an "out" for planned downtime. Customers will receive SLA credits for any downtime - planned or unplanned. Google claims to be the first major cloud provider to eliminate maintenance windows from its service level agreement.Google
Previously, Google did not count periods shorter than 10 minutes as downtime. That meant that even though short outages could add up to hours over a long enough period of time, the company had no obligation to compensate users. Google is ending that policy and will now credit users for any amount downtime, no matter how brief.
Source: The Radicati Group, 2010. "Corporate IT Survey - Messaging & Collaboration, 2010-2011.
Google claims its uptime in 2010 was 99.984%, even accounting for very short periods of downtime. That works out to seven minutes of downtime per month per user. Google cites a research by The Radicati Group finding that on-premise downtime is approximately 32 times more reliable than the average on-premise e-mail system.
Planned outages are a major loophole in most SLA agreements. Presumably, Google's redundant servers make it feasible for the company to conduct upgrades and migrations without taking systems offline.