Hi, all:

   I am a beginner of cassandra. I have a four node cassandra group.
   One of my cassandra group node had been running for a week. Recently because of too much writing and reading, it crashed.
I want to restart the node.
   While I start up cassandra, it ends up with throwing exception as follow every time:
   java.lang.RuntimeException: The provided key was not UTF8 encoded.
    at org.apache.cassandra.dht.OrderPreservingPartitioner.getToken(OrderPreservingPartitioner.java:170)
    at org.apache.cassandra.dht.OrderPreservingPartitioner.decorateKey(OrderPreservingPartitioner.java:42)
    at org.apache.cassandra.db.Table.apply(Table.java:380)
    at org.apache.cassandra.db.Table.apply(Table.java:354)
    at org.apache.cassandra.db.commitlog.CommitLogReplayer$1.runMayThrow(CommitLogReplayer.java:260)
    at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)


  I have googled and read the archive. But I can't find answer, please help me. Thank you very much.