The HBase isolation and allocation tool is designed to help users manage cluster resource among different application and tables.

When we have a large scale of HBase cluster with many applications running on it, there will be lots of problems. In Taobao there is a cluster for many departments to test their applications performance, these applications are based on HBase. With one cluster which has 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
Different groups can have different region server configurations, some groups optimized for reading can have large block cache size, and others optimized for writing can have large memstore size. 

Tables and region servers can be moved easily between groups; after changing the configuration, a group can be restarted alone instead of restarting the whole cluster.

另外推薦一個hbase的blog: http://hbase.iteye.com/  （BTW: 多麼好的blog名字啊～）