twitterがカッサンドラの使用開始

もとはfacebookのエンジニアによって開発され,その後オープンソースに変わったビックテーブルに似た非リレーショナル・データベースであるカッサンドラCassandraが,このほどtwitterで利用されることとなった。Cassandraはソーシャル・ネットワークのようなドメインでのランタイム・データベースとして理想なものといえる。

It is reasonable to seek a new tool for a new problem, and database problems have changed with the rise of web-scale distributed systems. This does not mean that SQL as a general-purpose runtime and reporting tool is going away. However, at web-scale, it is more flexible to separate the concerns. Runtime object lookups can be handled by a low-latency, strict, self-managed system like Cassandra. Asynchronous analytics and reporting can be handled by a high-latency, flexible, un-managed system like Hadoop. And in neither case does SQL lend itself to sharding. I think that Cassandra is the most promising current implementation of a runtime distributed database, but much work remains to be done. We're beginning to use Cassandra at Twitter, and here's what I would like to happen real-soon-now:

http://blog.evanweaver.com/articles/2009/07/06/up-and-running-with-cassandra/
http://d.hatena.ne.jp/huixing/20080822/p2p