Apache Hbase

HBase is a non-relational database meant for massively large tables of data that is implicitly distributed across clusters of commodity hardware. HBase provides “linear and modular scalability” and a variety of robust administration and data management features for your tables, all hosted atop Hadoop’s underlying HDFS file system. Designed to support queries of massive data sets, HBase is optimized for read performance. For writes, HBase seeks to maintain consistency. A write operation in HBase first records the data to a commit log (a "write-ahead log"), then to an internal memory structure called a MemStore. When the MemStore fills, it is flushed to disk as an entity called an HFile. HFiles are stored as a sequence of data blocks, with an index appended to the file's end. Another index, kept in memory, speeds searches for data in HFiles. HBase shards rows by regions, which are defined by a range of row keys. Every region in an HBase cluster is managed by a RegionServer process. Typically, there is a single RegionServer process per HBase node. As the amount of data grows, HBase splits regions and migrates the associated data to different nodes in the cluster for balancing purposes. HBase itself includes some built-in Web-based monitoring tools. An HBase master node serves a Web interface on port 60010. HBase offers a command shell, Java APIs, and REST APIs for managing everything, along with a variety of other integrations with popular big data storage, management, and processing / manipulation packages. HBase is an option on Amazon’s EMR, and is also available as part of Microsoft’s Azure offerings.