Date: Tue, 09 Mar 2010 21:42:33 +0900
2010年 3月 4日付けの Official Google Enterprise Blogに
"Disaster Recovery by Google", March 04, 2010
Posted by Rajen Sheth, Senior Product Manager, Google Apps
"For Google Apps customers, our RPO design target is zero, and our
RTO design target is instant failover. We do this through live or
synchronous replication: every action you take in Gmail is
simultaneously replicated in two data centers at once, so that if
one data center fails, we nearly instantly transfer your data over
to the other one that's also been reflecting your actions."
Our goal is not to lose any data when it's transferred from one
data center to another, and to transfer your data so quickly that
you don't even know a data center experiences an interruption. Of
course, no backup solution from us or anyone else is absolutely
perfect, but we've invested a lot of effort to help make it second
"And it's not just to preserve your Gmail accounts. You get the same
level of data replication for all the other major applications in
the Apps suite: Google Calendar, Google Docs, and Google Sites."
"Here are a few of the reasons why we're able to offer you this level
of service. First, we operate many large data centers simultaneously
for millions of users, which helps reduce cost while increasing
resiliency and redundancy. Second, we're not wasting money and
resources by having a data center stand-by unused until something
goes wrong - we can balance loads between data centers as needed.
Finally, we have very high speed connections between data centers,
so that we can transfer data very quickly from one set of servers to
another. This let us replicate large amounts of data simultaneously."
Official Google Enterprise Blogへの署名入り投稿なので、既にシステムは
"Google Steps Up Data Protection With Synchronous Replication"
March 5, 2010
"Google on said on 4 March that it has added a storage disaster-recovery
feature that’s growing in demand - synchronous data replication - to
its Google Apps lineup, which includes Google Docs, Gmail, Google
Sites, Calendar and several others."
The Data Liberation Front
"The Data Liberation Front is an engineering team at Google whose
singular goal is to make it easier for users to move their data in
and out of Google products."
"Run your business, not your email server
Gmail for business offers 25 GB of storage per user, powerful spam
filtering, BlackBerry and Outlook interoperability, and a 99.9%