Centos7 hive started to report an error. There is no route to the host. The firewall has been closed

Problem
hive startup error, firewall closed

	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.datanucleus.plugin.NonManagedPluginRegistry.createExecutableExtension(NonManagedPluginRegistry.java:606)
	at org.datanucleus.plugin.PluginManager.createExecutableExtension(PluginManager.java:301)
	at org.datanucleus.NucleusContextHelper.createStoreManagerForProperties(NucleusContextHelper.java:133)
	at org.datanucleus.PersistenceNucleusContextImpl.initialise(PersistenceNucleusContextImpl.java:420)
	at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.freezeConfiguration(JDOPersistenceManagerFactory.java:821)
	... 58 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:981)
	at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:339)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2253)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2286)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2085)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:795)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:327)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:208)
	at com.jolbox.bonecp.BoneCP.obtainRawInternalConnection(BoneCP.java:361)
	at com.jolbox.bonecp.BoneCP.<init>(BoneCP.java:416)
	... 70 more
Caused by: java.net.NoRouteToHostException: No route to the host (Host unreachable)
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:589)
	at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211)
	at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:298

I read all the tutorials on the Internet that it’s a firewall problem
but my firewall has been turned off

this hive is the one I copied from another virtual machine via SCP command
but the parameters in the hive site.xml have not changed

is changed to the corresponding host name
wq remains exit

start hadoop cluster
start hive
success!

[root@node01 conf]# hive
which: no hbase in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/export/servers/jdk1.8.0_131/bin:/export/servers/apache-zookeeper-3.6.2-bin/bin/:/export/servers/hadoop-2.7.7/bin/:/export/servers/hadoop-2.7.7/sbin/:/export/servers/apache-hive-2.1.1-bin/bin/:/root/bin)
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/export/servers/apache-hive-2.1.1-bin/lib/log4j-slf4j-impl-2.4.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/export/servers/hadoop-2.7.7/share/hadoop/common/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.apache.logging.slf4j.Log4jLoggerFactory]

Logging initialized using configuration in jar:file:/export/servers/apache-hive-2.1.1-bin/lib/hive-common-2.1.1.jar!/hive-log4j2.properties Async: true
Hive-on-MR is deprecated in Hive 2 and may not be available in the future versions. Consider using a different execution engine (i.e. spark, tez) or using Hive 1.X releases.
hive>