Hbase could not create table create table the card won't stay

HBase Shell cannot create a reason analysis for a table.

A. Phenomenon:

HBase was installed some time ago

HBase Shell

The list status command works correctly after you go in.

But execute the build statement:

Create ' AAA ', ' BBB '

He has been stuck there, not to report any errors, the log has been brushing the following debug log:

DEBUG org.apache.hadoop.hbase.client.hconnectionmanager$hconnectionimplementation:lookedup Root Region location, connection=org.apache.hadoop.hbase.client.hconnectionmanager$hconnectionimplementation@23faa614; Servername=

INFO org.apache.hadoop.hbase.master.ServerManager:Waiting on Regionserver (s) to checkin

And then I went into hive. You can also execute a view statement but not create a table.

The state is only readable and cannot be written.

Two. Workaround:

Namenode first enters the safe mode when the boot, if Datanode loses the block to reach a certain proportion, then the system will be in the Safe Mode state namely read-only state.

dfs.safemode.threshold.pct (default 0.999f) indicates that when HDFs starts, it is always this read-only mode if the number of blocks reported by Datanode reaches 0.999 times times the block number of the metadata record to leave safe mode. If set to 1, HDFs is always in safemode.

There are two ways to get out of this safe mode
(1) Modify dfs.safemode.threshold.pct to a relatively small value, the default is 0.999.
(2) Hadoop dfsadmin-safemode leave command forced to leave

The user can operate the Safe mode by Dfsadmin-safemode value, the parameter value is described as follows: 1. Enter-Enter Safe mode
2. Leave-Force Namenode to leave Safe mode
3. Get-Returns information about whether Safe mode is turned on
4. Wait-waits until the end of safe mode.

My approach is to force out of safe mode.

into the bin directory of Hadoop,

Perform:

Hadoop Dfsadmin-safemode Leave

Then I went into hive and HBase separately.

Create will be able to execute smoothly.