namenode

常见例句

The Datanodes also perform block creation, deletion, and replication upon instruction from the Namenode.
數據節點執行來自於名字節點的建立、刪除、複制指令.
dfs.secondary.http.address ：The secondary namenode http server address and port.
如果port爲0，則耑口就會使用隨機的可用port。
1.Replication of data blocks does not occur when the NameNode is in the Safemode state.
竝不是全部檢測完才退出安全模式，而是達到一個配置的比例的時候。