我搭建的是CDH集群。集群可以正常启动，但是一直报错困扰好久了，求救啊：
报错日志是这样的。
org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:102)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:129)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getConnectionForTransactionManagement(LogicalConnectionManagedImpl.java:247)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:254)
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.begin(JdbcResourceLocalTransactionCoordinatorImpl.java:203)
at org.hibernate.engine.transaction.internal.TransactionImpl.begin(TransactionImpl.java:56)
at com.cloudera.enterprise.AbstractWrappedEntityManager.begin(AbstractWrappedEntityManager.java:69)
at com.cloudera.cmf.persist.CmfEntityManager.begin(CmfEntityManager.java:292)
at com.cloudera.server.cmf.CommandPusherThread.handleCommandBatched(CommandPusherThread.java:246)
at com.cloudera.server.cmf.CommandPusherThread.innerLoop(CommandPusherThread.java:189)
at com.cloudera.server.cmf.CommandPusherThread.run(CommandPusherThread.java:157)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
这个问题很好解决，这个是因为你mysql版本的问题建议你下载mysql-5.7.28-1.el7.x86_64.rpm-bundle.tar这个版本的mysql就可以解决了
您好，这个问题解决了吗，我这也出现了这个