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HBase, mail # user - Co-processor seems to be failing to load


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Co-processor seems to be failing to load
techbuddy 2012-10-04, 06:25
Was trying to play around with Co-processors by trying to launch the
following co-processor of type RegionObserver in a standalone HBase
instance, deployed in distributed mode (meaning ZK, Region Server and Master
running as three separate JVM instances on the same host)

<property>
    <name>hbase.cluster.distributed</name>
    <value>true</value>
  </property>
Following is the simple co-processor code

package com.myemployer.group.project.hbase.monitoring.coprocessor;

<Import stmts>
public class HbaseMetricsDumper extends BaseRegionObserver {
        public static final Log log LogFactory.getLog(HbaseMetricsDumper.class);

        public void start(CoprocessorEnvironment e) throws IOException {
                log.debug(" Starting the co-processor HbaseMetricsDumper ");
        }

        public void preGet(ObserverContext<RegionCoprocessorEnvironment> e,
                        Get get, List<KeyValue> results) {
            
                 log.debug(" About to invoke 'get'  ");
                
             }                          
}

Here's the corresponding entry on the Hbase region server hbase-site.xml.

 <property>
  <name>hbase.coprocessor.region.classes</name>
  <value>com.myemployer.group.project.hbase.monitoring.coprocessor</value>
 </property>
Once I start hbase ,I don't see the expected log stmt " Starting the
co-processor HbaseMetricsDumper " logged in the start() method. Neither do I
see the log stmt logged through the preGet() callback.

Could anyone see the problem here..
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