有关 Master 的更多信息，请参阅 master 。
运行时，HBase 迁移脚本说根目录中没有文件。
HBase 期望根目录不存在，或者已经由 HBase 先前运行初始化。如果使用 Hadoop DFS 为 HBase 创建新目录，则会发生此错误。确保 HBase 根目录当前不存在或已由先前的 HBase 运行初始化。确定的解决方案是使用 Hadoop dfs 删除 HBase 根目录，让 HBase 创建并初始化目录本身。
如果群集中有许多区域，并且您在日志中看到此部分标题中上面报告的错误，请参阅 HBASE-4246 群集太多的区域无法承受某些主故障转移方案。
HBase 的集群操作内部框架需要能够在写入日志中持久保存状态。当使用支持检查所需呼叫可用性的 Apache Hadoop Common 文件系统 API 版本时，如果发现它无法安全运行，HBase 将主动中止群集。
对于主角色，失败将显示在这样的日志中：
2018-04-05 11:18:44,653 ERROR [Thread-21] master.HMaster: Failed to become active master
java.lang.IllegalStateException: The procedure WAL relies on the ability to hsync for proper operation during component failures, but the underlying filesystem does not support doing so. Please check the config value of 'hbase.procedure.store.wal.use.hsync' to set the desired level of robustness and ensure the config value of 'hbase.wal.dir' points to a FileSystem mount that can provide it.
at org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore.rollWriter(WALProcedureStore.java:1034)
at org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore.recoverLease(WALProcedureStore.java:374)
at org.apache.hadoop.hbase.procedure2.ProcedureExecutor.start(ProcedureExecutor.java:530)
at org.apache.hadoop.hbase.master.HMaster.startProcedureExecutor(HMaster.java:1267)
at org.apache.hadoop.hbase.master.HMaster.startServiceThreads(HMaster.java:1173)
at org.apache.hadoop.hbase.master.HMaster.finishActiveMasterInitialization(HMaster.java:881)
at org.apache.hadoop.hbase.master.HMaster.startActiveMasterManager(HMaster.java:2048)
at org.apache.hadoop.hbase.master.HMaster.lambda$run$0(HMaster.java:568)
at java.lang.Thread.run(Thread.java:745)
If you are attempting to run in standalone mode and see this error, please walk back through the section Quick Start - Standalone HBase and ensure you have included all the given configuration settings.