_firstEmitterIndex = String.valueOf(allCompNames.indexOf(_firstEmitter.getName()));
_secondEmitterIndex = String.valueOf(allCompNames.indexOf(_secondEmitter.getName()));
_parallelism = SystemParameters.getInt(conf, _ID + "_PAR");
_currentBolt = builder.setBolt(_ID, this, _parallelism);
final ThetaJoinDynamicMapping dMap = new ThetaJoinDynamicMapping(conf, -1);
// [0] because StormSrcJoin is considered dead
_currentBolt = _currentBolt.customGrouping(firstEmitter.getEmitterIDs()[0], dMap);
_currentBolt = _currentBolt.customGrouping(secondEmitter.getEmitterIDs()[0], dMap);