nutch-2.0 --Attempting to finish item from unknown queue

[al...@aim.com]

 

 Hello,

I use nutch-2.0 with hbase-0.92.1. in local mode.? After fetching for about 20 hours,

?I see error 
WARN? fetcher.FetcherJob - Attempting to finish item from unknown queue: FetchItem 
.....
.....
.....

folowed by 
java.net.ConnectException: Connection refused
??? at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
??? at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:701)
??? at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
??? at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:489)
??? at org.apache.hadoop.hbase.ipc.HBaseClient$Connection.setupConnection(HBaseClient.java:328)
??? at org.apache.hadoop.hbase.ipc.HBaseClient$Connection.setupIOstreams(HBaseClient.java:362)
??? at org.apache.hadoop.hbase.ipc.HBaseClient.getConnection(HBaseClient.java:1045)
??? at org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:897)
??? at org.apache.hadoop.hbase.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:150)
??? at $Proxy6.getClosestRowBefore(Unknown Source)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegionInMeta(HConnectionManager.java:947)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:814)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.relocateRegion(HConnectionManager.java:788)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegionInMeta(HConnectionManager.java:1024)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:818)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.processBatchCallback(HConnectionManager.java:1524)
??? at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.processBatch(HConnectionManager.java:1409)
??? at org.apache.hadoop.hbase.client.HTable.flushCommits(HTable.java:943)
??? at org.apache.hadoop.hbase.client.HTable.doPut(HTable.java:820)
??? at org.apache.hadoop.hbase.client.HTable.put(HTable.java:795)
??? at org.apache.gora.hbase.store.HBaseTableConnection.put(HBaseTableConnection.java:187)
??? at org.apache.gora.hbase.store.HBaseStore.put(HBaseStore.java:243)
??? at org.apache.gora.mapreduce.GoraRecordWriter.write(GoraRecordWriter.java:60)
??? at org.apache.hadoop.mapred.ReduceTask$NewTrackingRecordWriter.write(ReduceTask.java:587)
??? at org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)


I read on the internet that this could happen because hadoop's tasktracker goes down. 

Any ideas how to debug this issue?

Thanks in advance.
Alex.