flume 写入hadoop时报错。?报错

2015-08-10 16:01:22,819 (SinkRunner-PollingRunner-DefaultSinkProcessor)
 [ERROR - org.apache.flume.sink.hdfs.HDFSEventSink.process(HDFSEventSink.java:422)] process failed
java.lang.VerifyError: class org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$SetOwnerRequestProto overrides final method getUnknownFields.()Lcom/google/protobuf/UnknownFieldSet;
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)

at java.lang.Class.getDeclaredMethods0(Native Method)

有遇到过类似问题的吗？求解脱~！