Database Reference
In-Depth Information
Geographical Distribution
Cassandra has out-of-the-box support for geographical distribution of data. You can easily con-
figure Cassandra to replicate data across multiple data centers. If you have a globally deployed
application that could see a performance benefit from putting the data near the user, Cassandra
could be a great fit.
Evolving Applications
If your application is evolving rapidly and you're in “startup mode,” Cassandra might be a good
it given its schema-free data model. This makes it easy to keep your database in step with ap-
plication changes as you rapidly deploy.
Who Is Using Cassandra?
Cassandra is still in its early stages in many ways, not yet seeing its 1.0 release at the time of
this writing. There are few easy, graphical tools to help manage it, and the community has not
settled on certain key internal and external design questions that have been revisited. But what
does it say about the promise, usefulness, and stability of a data store that even in its early stages
is being used in production by many large, well-known companies?
NOTE
It is a logical fallacy, informally called the Bandwagon Fallacy, to argue that just because something is
growing in popularity means that it is “true.” Cassandra is without a doubt enjoying skyrocketing growth
in popularity, especially over the past year or so. Still, my point here is that the many successful produc-
tion deployments at a variety of companies for a variety of purposes is sufficient to suggest its usefulness
and readiness.
The list of companies using Cassandra is growing. These companies include:
▪ Twitter is using Cassandra for analytics. In a much-publicized blog post (at
ht-
tp://engineering.twitter.com/2010/07/cassandra-at-twitter-today.html
)
, Twitter's primary
Cassandra engineer, Ryan King, explained that Twitter had decided against using Cassandra
as its primary store for tweets, as originally planned, but would instead use it in production
for several different things: for real-time analytics, for geolocation and places of interest data,
and for data mining over the entire user store.
▪ Mahalo uses it for its primary near-time data store.
▪ Facebook still uses it for inbox search, though they are using a proprietary fork.
