CDH3のエラー（あとでしらべる）

class not found

2/07/13 14:26:14 INFO mapred.JobClient: Task Id : attempt_201207121852_0020_r_000000_2, Status : FAILED
Error: java.lang.ClassNotFoundException: Ljava.lang.InternalError
	at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at org.apache.hadoop.io.compress.snappy.SnappyDecompressor.decompressBytesDirect(Native Method)
	at org.apache.hadoop.io.compress.snappy.SnappyDecompressor.decompress(SnappyDecompressor.java:234)
	at org.apache.hadoop.io.compress.BlockDecompressorStream.decompress(BlockDecompressorStream.java:82)
	at org.apache.hadoop.io.compress.DecompressorStream.read(DecompressorStream.java:75)
	at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.shuffleInMemory(ReduceTask.java:1626)
	at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getMapOutput(ReduceTask.java:1

too many fetch failuresのtask attempt

2012-07-13 12:01:33,623 INFO org.apache.hadoop.mapred.TaskTracker.clienttrace: src: 192.168.201.203:50060, dest: 192.168.201.202:33174, bytes: 0, op: MAPRED_SHUFFLE, cliID: attempt_201207121852_0008_m_000159_0, duration: 6017682
2012-07-13 12:01:33,623 ERROR org.mortbay.log: /mapOutput
java.lang.IllegalStateException: Committed
	at org.mortbay.jetty.Response.resetBuffer(Response.java:1023)
	at org.mortbay.jetty.Response.sendError(Response.java:240)
	at org.apache.hadoop.mapred.TaskTracker$MapOutputServlet.doGet(TaskTracker.java:4158)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
	at org.apache.hadoop.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:864)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
	at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
	at org.mortbay.jetty.Server.handle(Server.java:326)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
	at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
2012-07-13 12:01:33,739 INFO org.apache.hadoop.mapred.TaskTracker: JVM with ID: jvm_201207121852_0008_m_1836611507 given task: attempt_201207121852_0008_m_000174_0