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Project scenario: Problem Description: Cause Analysis: solution:

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Project scenario:

Ubuntu20.04Hadoop3.2.2Hbase2.2.2

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Problem Description:

The main errors are as follows: error: org.apache.hadoop.hbase.pleaseholdexception: Master is initializing

After starting the HBase shell, when using create, list and other commands, the following error messages appear:

hbase(main):001:0> list
TABLE 
                                                                                                                    
ERROR: org.apache.hadoop.hbase.PleaseHoldException: Master is initializing
        at org.apache.hadoop.hbase.master.HMaster.checkInitialized(HMaster.java:2452)
        at org.apache.hadoop.hbase.master.MasterRpcServices.getTableNames(MasterRpcServices.java:915)
        at org.apache.hadoop.hbase.protobuf.generated.MasterProtos$MasterService$2.callBlockingMethod(MasterProtos.java:58517)
        at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2339)
        at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:123)
        at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:188)
        at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:168)

For usage try 'help "list"'

Took 10.297 seconds

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Cause analysis:

Here, my computer is only configured with HBase application for Hadoop pseudo distributed cluster, so I don’t think it’s possible that the time of HBase and zookeeper servers is inconsistent, as others on the Internet say. The main reason should be: the processes of Hadoop and HBase are inconsistent, resulting in the initialization of the master node all the time

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Solution:

Format the HBase file system in Hadoop, restart HBase, and resynchronize the two:

Shut down all HBase services first:

cd /usr/local/hbase
bin/stop-hbase.sh

Then close all Hadoop services:

cd /usr/local/hadoop
sbin/stop-all.sh

Enter JPS to ensure that all Hadoop and HBase processes are closed:

zq@fzqs-Laptop:~$ jps
4673 Jps

Then start the Hadoop service:

cd /usr/local/hadoop
sbin/start-all.sh

To view files in HDFS:

bin/hdfs dfs -ls /

The output shall be as follows (including/HBase):

zq@fzqs-Laptop:/usr/local/hadoop$ bin/hdfs dfs -ls /
Found 1 items
drwxr-xr-x		- root supergroup 		0 2021-10-28 21:49 /hbase

Delete/HBase Directory:

bin/hdfs dfs -rm -r /hbase

Start HBase service:

cd /usr/local/hbase
bin/start-hbase.sh

Then start the shell and you should be able to use it:

bin/hbase shell