Files stored in Google Docs or in Gmail are broken up into digital pieces and stored on random servers for reassembly when needed
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 search and web services giant told eWEEK that it, in fact, has been using replication for Gmail for a few years, but that it is has now extended the feature to all of its online tools and services.
Digital file replication is a method in which data files are copied and filed in one or more locations apart from the central data centre as a backup and disaster-recovery mechanism.
Data replication is the process of copying a portion of a database from one environment to another and keeping the subsequent copies of the data in sync with the original source. Changes made to the original source are propagated to the copies of the data in other environments.
“We’ve been quietly working on this for a while,” Google spokesman Andrew Kovacs told eWEEK. “It’s nothing that a user will ever see online. It all works in the background and doesn’t affect anything the user does.”
Files stored in Google Docs or in Gmail files are broken up into digital pieces [some people call them “chunks”] and stored on random servers in Google data centres around the world. When the time comes to gather the file back up for download or online viewing, the pieces are quickly reassembled for the user’s session.
“Here are a few of the reasons why we’re able to offer you this level of service,” Rajen Sheth, Senior Product Manager of Google Apps, wrote in a blog post. “First, we operate many large data centres 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 centre stand by unused until something goes wrong; we can balance loads between data centres as needed. Finally, we have very high speed connections between data centres, so that we can transfer data very quickly from one set of servers to another. This let us replicate large amounts of data simultaneously.”
Replacing SAN functionality
Sheth said that Google Apps and its backup and disaster-recovery systems – which now include the replication feature – can replace a lot of the functionality that a conventional data centre SAN [storage area network] brings to an enterprise, and for a lot less up-front cost.
“SANs are expensive, and even then, you’re out of luck if your data centre goes down,” Sheth said. “So the largest enterprises will build an entirely new data centre somewhere else, with another set of identical mail servers, another SAN and more people to staff them. But if, heaven forbid, disaster strikes both your data centres, you’re toast.”
“Google Apps customers don’t need to worry about any of this, for the data they create and store within Google Apps. They get best-in-class disaster recovery for free, no matter their size.”