Hadoop HDFS HA show two StandBy NameNode
The reason may be that the zkfc service is not started. The correct process is as follows
It is important to ensure that the Hadoop NameNode is running before starting the ZKFC, as the ZKFC relies on the NameNode to perform its functions.
1. Format the ZKFC on nn001
sudo -u hdfs hdfs zkfc -formatZK
2. Start journalnode on three (or more) nodes
service hadoop-hdfs-journalnode start
3. Format the NameNode on nn001 and start nn
sudo -u hdfs hdfs namenode -format
service hadoop-hdfs-namenode start
4. Format the standby namenode on nn002
sudo -u hdfs hdfs namenode -bootstrapStandby
service hadoop-hdfs-namenode start
5. Start the zkfc service on nn001 and nn002
nn001/nn002
service hadoop-hdfs-zkfc start