> > org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException: > org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException: No matching > handler for protocol org.apache.hadoop.hbase.coprocessor.AggregateProtocol > in region transactions,,1335223974116.e9190687f8a74b5083b39b6e5bd55705.
The exception indicates that the AggregateImplementation coprocessor is not loaded on your region servers. Setting "hbase.coprocessor.region.classes" in the client configuration that you use is not sufficient. You need to either set this in the hbase-site.xml file used by your region servers (and restart the region servers), or you can enable the coprocessor for a specific table by disabling the table, setting a property on the HTableDescriptor and re-enabling the table. For more details, see http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/coprocessor/package-summary.html#package_description
