It could be also caused by the MR takes too long to process a batch of data before coming back for another batch.
Thanks, Jimmy On Tue, Jul 24, 2012 at 11:52 AM, Jeff Whiting <[email protected]> wrote: > What would cause a scanner timeout exception? Is hdfs too slow? Do I just > increase the scanner timeout or is there a better approach. > > Thanks, > ~Jeff > > running: hadoop jar /usr/lib/hbase/hbase-0.90.1-CDH3B4.jar export -D > dfs.replication=2 -D mapred.output.compress=true -D > mapred.output.compression.codec=org.apache.hadoop.io.compress.GzipCodec -D > mapred.output.compression.type=BLOCK response /hbaseBackup/ > partial/2012-07-20_2012-07-21/response 1 1342742400000 1342828800000 > org.apache.hadoop.hbase.client.ScannerTimeoutException: 61294ms passed since > the last invocation, timeout is currently set to 60000 > at > org.apache.hadoop.hbase.client.HTable$ClientScanner.next(HTable.java:1114) > at > org.apache.hadoop.hbase.mapreduce.TableRecordReaderImpl.nextKeyValue(TableRecordReaderImpl.java:143) > at > org.apache.hadoop.hbase.mapreduce.TableRecordReader.nextKeyValue(TableRecordReader.java:142) > at > org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:455) > at > org.apache.hadoop.mapreduce.MapContext.nextKeyValue(MapContext.java:67) > at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143) > at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:646) > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:322) > at org.apache.hadoop.mapred.Child$4.run(Child.java:240) > at java.security.AccessController.doPrivileged(Native Method) > at javax.security.auth.Subject.doAs(Subject.java:396) > at > org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1115) > at org.apache.hadoop.mapred.Child.main(Child.java:234) > Caused by: org.apache.hadoop.hbase.UnknownScannerException: > org.apache.hadoop.hbase.UnknownScannerException: Name: -3564751891935236449 > at > org.apache.hadoop.hbase.regionserver.HRegionServer.next(HRegionServer.java:1795) > at sun.reflect.GeneratedMethodAccessor16.invoke(Unknown Source) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at > org.apache.hadoop.hbase.ipc.HBaseRPC$Server.call(HBaseRPC.java:570) > at > org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:1039) > > at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native > Method) > at > sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) > at > sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) > at java.lang.reflect.Constructor.newInstance(Constructor.java:513) > at > org.apache.hadoop.hbase.RemoteExceptionHandler.decodeRemoteException(RemoteExceptionHandler.java:96) > at > org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:83) > at > org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:38) > at > org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithRetries(HConnectionManager.java:1000) > at > org.apache.hadoop.hbase.client.HTable$ClientScanner.next(HTable.java:1100) > ... 12 more > > -- > Jeff Whiting > Qualtrics Senior Software Engineer > [email protected] >
