> From: Michael Segel > Imagine you have a cloud of 100 hadoop nodes. > In theory you could create multiple instances of HBase on > the cloud. > Obviously I don't think you could have multiple region > servers running on the same node. > The use case I was thinking about if you have a centralized > hadoop cloud and you wanted to have multiple developer > groups sharing the cloud as a resource rather than building > their own clouds.
This is somewhat like HOD (http://hadoop.apache.org/common/docs/current/hod_user_guide.html). Have you looked at that? > The reason for the multiple hbase instances is that you > don't have a way of setting up multiple instances like > different Informix or Oracle databases/schemas on the same > infrastructure. Right. Well there is a simple (and under development, lightly tested as yet, etc.) multiuser mode in Stargate that gives multiple users each the illusion of a private HBase instance while sharing a common HBase cluster underneath. This is something I'll continue to work on as I have time. Also my employer is sponsoring development of HBASE-1697, and integration of HBase into the secure version of Hadoop (http://bit.ly/75011o) that Yahoo is working on. For example HBase would offer RBAC and might also use HDFS block tokens in a manner that allows you to reason about user isolation down through the whole stack. salesforce.com is a multitenant service built on a shared database infrastructure. They've talked about their rationale for building their SaaS service this way. It's worth it to Google a bit to find it and read. Partitioning cloud resources increases management complexity and reduces the benefit of the cloud -- the efficiencies of scale. It's technically possible to partition cloud resources but economically inefficient and suboptimal to do so. - Andy
