Observations

Just wrote a couple of methods in my main mock class.

public void failingOn(String regex) {
  this.failureCondition = regex;
}

public void maybeFail(Object...objects) throws HBaseException {
  if (failureCondition != null) {
            String s = Arrays.asList(objects).toString();
    if (s.matches(failureCondition)) {
      throw new HBaseException("Congratulations, you hit the jackpot today: " + s);
    }
  }
}

and most of the methods look like this:

@Override
public void bulkDelete(String tableName, Collection rowKeys, String columnFamily) throws HBaseException {
  maybeFail("bulkDelete", tableName, rowKeys, columnFamily);
  table(tableName).family(columnFamily).delete(rowKeys);
}

Now in the test I write stuff like this:

@Test    
public void testPut_replicating_withErrors() throws Exception {
  MockHBaseOperations cluster2 = new MockHBaseOperations();
  cluster2.failingOn("\\[sendToCluster, BadTable,.*");
  ...
}

... do you need explanations on how it works?

What I personally enjoy here is the leisure JavaScript coding style, where you just join the arguments, not giving a fuck about their types.