An error is reported when the Flink SQL client submits the job:

2021-10-21 15:23:54,232 INFO  org.apache.flink.yarn.YarnClusterDescriptor                  [] - No path for the flink jar passed. Using the location of class org.apache.flink.yarn.YarnClusterDescriptor to locate the jar
2021-10-21 15:23:54,233 WARN  org.apache.flink.yarn.YarnClusterDescriptor                  [] - Neither the HADOOP_CONF_DIR nor the YARN_CONF_DIR environment variable is set.The Flink YARN Client needs one of these to be set to properly load the Hadoop configuration for accessing YARN.
2021-10-21 15:23:54,291 INFO  org.apache.hadoop.yarn.client.ConfiguredRMFailoverProxyProvider [] - Failing over to rm2
2021-10-21 15:23:54,337 INFO  org.apache.flink.yarn.YarnClusterDescriptor                  [] - Found Web Interface n101:36989 of application 'application_1634635118307_0001'.
[ERROR] Could not execute SQL statement. Reason:
org.apache.flink.runtime.client.JobSubmissionException: Failed to submit JobGraph.

Failing over to rm2

Only active namenode can be submitted successfully. My active namenode is RM2