I'm using CDH4, but I'd imagine that the steps would be similar for upstream HBase. I've already got the tests JAR file loaded as part of my classpath. I also have the following in my hbase-site.xml: <property> <name>hbase.coprocessor.region.classes</name> <value>org.apache.hadoop.hbase.coprocessor.SampleRegionWALObserver</value> </property>
When I start HBase, the following shows up in my logs: # grep Sample /var/log/hbase/hbase-hbase-regionserver-hbase01.log 2012-10-24 13:06:13,126 INFO org.apache.hadoop.hbase.coprocessor.CoprocessorHost: System coprocessor org.apache.hadoop.hbase.coprocessor.SampleRegionWALObserver was loaded successfully with priority (536870911). However, when I 'PUT' new rows in my table, I see no log entries show up for SampleRegionWALObserver. After looking at the SampleRegionWALObserver code, it seems that I need to call setTestValues() in order to get preWALWrite() to execute the rest of the code. I think this is something that I might be able to accomplish via the 'hbase shell', but I can't figure out how. Can anyone help point me in the right direction? For reference, this is the code I'm looking at: http://svn.apache.org/repos/asf/hbase/tags/0.92.1/src/test/java/org/apache/hadoop/hbase/coprocessor/SampleRegionWALObserver.java Regards, Michael Spiegle
