Cloudera’s Operational Database (OpDB) supports a scale-up (SMP) environment. The caching layer is able to consume all memory in a large SMP environment. Memory has to be large enough to cover RegionServers, DataNodes and operating system, and to have enough extra space to allow the block cache to assist with reads. When HBase is running with other components, CPU contention and memory contention can be a problem that is easy to address with proper YARN tuning.
As a result of the scale-up architecture, multiple services and engines can be run on a single node. For smaller nodes, multiple services and engines have to be spread out amongst a larger set of nodes.
The Cloudera Operational Database (COD) experience is a managed dbPaaS solution which abstracts the underlying cluster instance as a Database. It can auto-scale based on the workload utilization of the cluster and will be adding the ability to auto-tune (better performance within the existing infrastructure footprint) and auto-heal (resolve operational problems automatically) later this year. It offers multi-modal client access with NoSQL key-value using Apache HBase APIs and relational SQL with JDBC (via Apache Phoenix). The latter makes COD accessible to developers who are used to building applications that use MySQL, Postgres, etc.
It’s interesting to see Cloudera move in this direction.