Dear Wiki user, You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.
The following page has been changed by EvgenyRyabitskiy: http://wiki.apache.org/hadoop/Hbase/DesignOverview ------------------------------------------------------------------------------ HBase is an [http://apache.org/ Apache] open source project whose goal is to provide Bigtable-like storage for the Hadoop Distributed Computing Environment. HBase leverages the distributed data storage provided by the [http://hadoop.apache.org/core/docs/current/hdfs_design.html Hadoop Distributed File System (HDFS)] and use [http://hadoop.apache.org/zookeeper/docs/current/zookeeperOver.html ZooKeeper] for coordination between HBase nodes. - Data is logically organized into tables, rows and columns. An iterator-like interface is available for scanning through a row range and, of course, there is the ability to retrieve a column value for a specific row key. Any particular column may have multiple versions for the same row key. + Data is logically organized into tables, rows and columns. An iterator-like interface is available for scanning through a row range and, of course, there is the ability to retrieve a column value for a specific row key. Any particular column may have multiple versions for the same row key. [[Anchor(datamodel)]] = Data Model = @@ -115, +115 @@ [[Anchor(master)]] == HMaster == - There is only one HMaster for a single HBase deployment. + There is only one HMaster for a single HBase deployment. To ensure that there is always one active HMaster uses [http://hadoop.apache.org/zookeeper/docs/current/recipes.html#sc_leaderElection leader election algorithm] and it's address is stored in !ZooKeaper. HMaster duties: @@ -123, +123 @@ * Assigning/unassigning regions to/from H!RegionServers (unassigning is for load balance) * Monitor the health of each H!RegionServer * Changes to the table schema and handling table administrative functions + + == Cluster initialization == + + === Assigning regions to HRegionServers ===
