Major compaction queue monitoring

[Ioakim Perros]

Hi,

I would like to programmatically major compact a table's regions, but I 
would like to check if major compaction ended (i.e.: compaction queue 
size goes to zero).

I tried to do it through the following code but it failed throwing a 
null pointer exc.

HBaseAdmin admin = new HBaseAdmin(config);
admin.majorCompact("myTable");
admin.close();
HRegionServer hr = new HRegionServer(config);
try {
       if ( ! (hr.getMetrics().compactionQueueSize.get()==0)  ){
            System.out.println( 
hr.getMetrics().compactionQueueSize.get() );
            Thread.sleep(1000);
      }
} catch(InterruptedException ex) {
       Thread.currentThread().interrupt();
}

Does anyone know how to correctly check this?

Thanks in advance,
IP