我正在尝试从denodo平台访问配置单元，但收到以下错误消息

"Unable to establish connection: Could not open client transport with JDBC Uri: jdbc:hive2://hostname:portnumber: java.net.ConnectException: Connection refused: connect ".

它以前使用相同的配置，现在突然停止工作。在检查hive.log文件时，我发现：

> ERROR [pool-3-thread-5]: server.TThreadPoolServer (TThreadPoolServer.java:run(294)) - Thrift error occurred during processing of message.
org.apache.thrift.protocol.TProtocolException: Missing version in readMessageBegin, old client?
    at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:228)
    at org.apache.hadoop.hive.metastore.TUGIBasedProcessor.process(TUGIBasedProcessor.java:75)
    at org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:285)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:748)

我重新启动了服务，namenode的safemode关闭了，远程服务器的防火墙关闭了，jdbc驱动程序配置正确。
我无法调试日志文件，任何帮助将不胜感激。