HBase source code analysis: org. apache. hadoop. hbase. master. handler package

In this package, some Executor thread pool services provided by the master are used to call ClosedRegionHandler. If the table is disabled, delete the unassigned node on the zk and delete it from the transition state; otherwise, allocate another server. CreateTableHandler: when calling the interface on the master to create a Table, you can specify the splitkey or not. Create a table and a region directory on the hdfs node under the table node on the zookeeper, create a region, and insert it to the META table to assign regions to the regionServer. Set this table to the enable State DeleteTableHandler, DisableTableHandler, EnableTableHandler, handler, ModifyTableHandler, and OpenedRegionHandler under the zookeeper table node, some cleanup work, such as deleting the region node information under unassigned on zookeeper, synchronizing the RegionState information on AssignmentManager ServerShutdownHandler after the server shutdown or expire, after the master monitors it, A series of migration re Gion, log split, and cleanup actions. During the processing, split log is performed on the HLog of the server. If the server holds the ROOT and META information, the ROOT and META will be re-allocated until the META is re-allocated, allocate the original region SplitRegionHandler held on the server and complete the subsequent split Processing. For example, update the cache information related to the region and daughters on AssignmentManger, delete the current region information under unassigned on zookeeper. The following three handler are inherited from the TableEventHandler scan META table, get the regions information of the table, update the table desc information on HDFS and in memory. If the current table is in the enable state, then open all region again. TableAddFamilyHandler, TableDeleteFamilyHandler, TableModifyFamilyHandler to be improved and supplemented .....