namenode is in safe mode

[#1]

from the logs we can see that

what is the command to get name not not in safe mode ?

        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1866)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2345)
Caused by: org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create file/spark2-history/.cffb30ea-b88b-4044-8e1d-017039458f94. Name node is in safe mode.
The reported blocks 4 needs additional 10 blocks to reach the threshold 0.9900 of total blocks 14.
The number of live datanodes 3 has reached the minimum number 0. Safe mode will be turned off automatically once the thresholds have been reached.
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkNameNodeSafeMode(FSNamesystem.java:1391)
        ... 13 more

[#2 · Accepted solution]

hdfs dfsadmin -safemode leave

[#3]

Why is it namenode become safe mode?

[#4]

Command To Check SafeMode On/Off: hdfs dfsadmin -safemode get

Command To Get Out Of Safe Mode Shared Above.