public class CustomComparator extends WritableByteArrayComparable
{
final CimKeyType cimKeyType;
final byte[] value;
public CustomComparator(byte[] value, CimKeyType cimKeyType)
{
super(value);
this.value = value;
this.cimKeyType = cimKeyType;
}
@Override
public int compareTo(byte[] value)
{
int differenceValue;
switch (cimKeyType)
{
case INTEGER:
differenceValue = Bytes.toInt(this.value) - Bytes.toInt(value);
break;
case LONG:
differenceValue = (int) (Bytes.toLong(this.value) -
Bytes.toLong(value));
break;
case DOUBLE:
differenceValue = (int) (Bytes.toDouble(this.value) -
Bytes.toDouble(value));
break;
case STRING:
default:
differenceValue =
Bytes.toString(this.value).compareTo(Bytes.toString(value));
}
System.out.println("differenceValue : " +differenceValue);
return differenceValue;
}
}
CustomComparator comparator = new CustomComparator(filterValue,
lField.getCimKeyType());
//BinaryComparator comparator = new BinaryComparator(filterValue);
SingleColumnValueFilter singleColumnValueFilter = new
SingleColumnValueFilter(Bytes.toBytes(familyAndCol[0]),
Bytes.toBytes(familyAndCol[1]), compareOperator, comparator);
if (myNumberOfVersions > 0)
get.setMaxVersions(myNumberOfVersions);
if (filterList != null)
get.setFilter(filterList);
Result result = hTable.get(get);
I m using the above code inside hadoop-mapper. I had make it jar and placed
it inside both hadoop/lib and hbase/lib.
If i use BinaryComparator, i m not getting any exception, and error. But if
I used CustomComparator, I m getting the follwoing Exception.
at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:391)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:325)
at org.apache.hadoop.mapred.Child$4.run(Child.java:270)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1127)
at org.apache.hadoop.mapred.Child.main(Child.java:264)
Caused by: org.apache.hadoop.hbase.client.RetriesExhaustedException:
Trying to contact region server localhost:50682 for region
mytable,,1325226129670.708fa93842d13d3448295d88906d7ab8., row '444',
but failed after 10 attempts.
Exceptions:
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
java.io.IOException: Call to localhost/127.0.0.1:50682 failed on
local exception: java.io.EOFException
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithRetries(HConnectionManager.java:1024)
at org.apache.hadoop.hbase.client.HTable.get(HTable.java:555)
at
... 12 more
2011-12-30 13:36:30,175 INFO org.apache.hadoop.mapred.Task:
Runnning cleanup for the task
command line jps output is
18667 HMaster
17929 NameNode
21942 Jps
18266 SecondaryNameNode
18100 DataNode
19143 Main
18523 TaskTracker
18362 JobTracker
8641
here mytable is my hbase table name and 444 is rowkey
Development environment : Ubuntu-11.10, Java-6, Hadoop and Hbase from
Cloudera CDH3U2
--
Regards,
Nageswaran S
