public void connectToPredecessors( Map<IntermediateDataSetID, IntermediateResult> intermediateDataSets) throws JobException { List<JobEdge> inputs = jobVertex.getInputs(); if (LOG.isDebugEnabled()) { LOG.debug( String.format( "Connecting ExecutionJobVertex %s (%s) to %d predecessors.", jobVertex.getID(), jobVertex.getName(), inputs.size())); } for (int num = 0; num < inputs.size(); num++) { JobEdge edge = inputs.get(num); if (LOG.isDebugEnabled()) { if (edge.getSource() == null) { LOG.debug( String.format( "Connecting input %d of vertex %s (%s) to intermediate result referenced via ID %s.", num, jobVertex.getID(), jobVertex.getName(), edge.getSourceId())); } else { LOG.debug( String.format( "Connecting input %d of vertex %s (%s) to intermediate result referenced via predecessor %s (%s).", num, jobVertex.getID(), jobVertex.getName(), edge.getSource().getProducer().getID(), edge.getSource().getProducer().getName())); } } // fetch the intermediate result via ID. if it does not exist, then it either has not been // created, or the order // in which this method is called for the job vertices is not a topological order IntermediateResult ires = intermediateDataSets.get(edge.getSourceId()); if (ires == null) { throw new JobException( "Cannot connect this job graph to the previous graph. No previous intermediate result found for ID " + edge.getSourceId()); } this.inputs.add(ires); int consumerIndex = ires.registerConsumer(); for (int i = 0; i < parallelism; i++) { ExecutionVertex ev = taskVertices[i]; ev.connectSource(num, ires, edge, consumerIndex); } } }