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HBase, mail # user - The Exceptions When Concurrently Writing and Reading


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Re: The Exceptions When Concurrently Writing and Reading
Ted Yu 2013-02-05, 18:45
To help us more easily correlate line numbers, can you tell us the version
of HBase you're using ?

Thanks

On Tue, Feb 5, 2013 at 10:39 AM, Bing Li <[EMAIL PROTECTED]> wrote:

> Dear all,
>
> To raise the performance of writing data into HBase, the
> "synchronized" is removed from the writing method.
>
> But after "synchronized" is removed from the method of writing, I get
> the following exceptions when reading. Before the removal, no such
> exceptions.
>
> Could you help me how to solve it?
>
> Thanks so much!
>
> Best wishes,
> Bing
>
>       Feb 6, 2013 12:21:31 AM
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection run
>       WARNING: Unexpected exception receiving call responses
> java.lang.NullPointerException
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readObject(HbaseObjectWritable.java:521)
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readFields(HbaseObjectWritable.java:297)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.receiveResponse(HBaseClient.java:593)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:505)
>       Feb 6, 2013 12:21:31 AM
> org.apache.hadoop.hbase.client.ScannerCallable close
>       WARNING: Ignore, probably already closed
>       java.io.IOException: Call to greatfreeweb/127.0.1.1:60020
> failed on local exception: java.io.IOException: Unexpected exception
> receiving call responses
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient.wrapException(HBaseClient.java:934)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:903)
>           at
> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:150)
>           at $Proxy6.close(Unknown Source)
>           at
> org.apache.hadoop.hbase.client.ScannerCallable.close(ScannerCallable.java:112)
>           at
> org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:74)
>           at
> org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:39)
>           at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithRetries(HConnectionManager.java:1325)
>           at
> org.apache.hadoop.hbase.client.HTable$ClientScanner.nextScanner(HTable.java:1167)
>           at
> org.apache.hadoop.hbase.client.HTable$ClientScanner.next(HTable.java:1296)
>           at
> org.apache.hadoop.hbase.client.HTable$ClientScanner$1.hasNext(HTable.java:1356)
>           at
> com.greatfree.hbase.rank.NodeRankRetriever.LoadNodeGroupNodeRankRowKeys(NodeRankRetriever.java:348)
>           at
> com.greatfree.ranking.PersistNodeGroupNodeRanksThread.run(PersistNodeGroupNodeRanksThread.java:29)
>           at
> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>           at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>           at java.lang.Thread.run(Thread.java:662) Caused by:
> java.io.IOException: Unexpected exception receiving call responses
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:509)
>       Caused by: java.lang.NullPointerException
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readObject(HbaseObjectWritable.java:521)
>           at
> org.apache.hadoop.hbase.io.HbaseObjectWritable.readFields(HbaseObjectWritable.java:297)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.receiveResponse(HBaseClient.java:593)
>           at
> org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:505)
>
> The writing method is as follows.
>
>
> // The "synchronized" is removed to raise the performance.
> // public synchronized void AddNodeViewGroupNodeRanks(String
> hostNodeKey, String groupKey, int timingScale, Map<String, Double>
> groupNodeRankMap)
>
> public void AddNodeViewGroupNodeRanks(String hostNodeKey, String
> groupKey, int timingScale, Map<String, Double> groupNodeRankMap)
> {