HBase一个非常实用而有趣的新功能，表的分组和优先级设定
HBASE-4120
The HBase allocation tool is designed to help users manage cluster resource among different application and tables.
When we manage a large scale of HBase cluster with many applications running on it, there will be lots of problems. In Taobao[1] there is a cluster for many departments to test their applications performance, these applications are based on HBase. With one cluster which have 12 servers, there will be only one application running exclusively on this server, and many other applications must wait until the previous test finished.
After we add allocation manage function to the cluster, applications can share the cluster and run concurrently. Also if the Test Engineer wants to make sure there is no interference, he/she can move out other tables from this group.
In groups we use table priority to allocate resource, when system is busy; we can make sure high-priority tables are not affected lower-priority tables

大家英文很好，不过我还是嗦一下啦。

就是把HBase大集群分组成多个孤立的group，每个group可以有多个表。而每个表可以有优先级。优先级高的表响应速度快。

这个的好处很多。
1. 测试方便。
2. 孤立了，如果再加上ACL，每个application各自搞各自的，互不影响。

我没有使用过。但是看了觉得很兴奋。有空可以试试。

但是不知道操作起来会不会很麻烦。 hbase变得越来越复杂了。

这个中科院的一位牛人为淘宝做的。不知道淘宝的同学有没有使用呀。可以说说使用心得。