private void initializeGroupInputs() throws TezException { if (groupInputSpecs != null && !groupInputSpecs.isEmpty()) { groupInputsMap = new ConcurrentHashMap<String, MergedLogicalInput>(groupInputSpecs.size()); for (GroupInputSpec groupInputSpec : groupInputSpecs) { if (LOG.isDebugEnabled()) { LOG.debug("Initializing GroupInput using GroupInputSpec: " + groupInputSpec); } MergedInputContext mergedInputContext = new TezMergedInputContextImpl(groupInputSpec.getMergedInputDescriptor().getUserPayload(), groupInputSpec.getGroupName(), groupInputsMap, inputReadyTracker, localDirs, this); List<Input> inputs = Lists.newArrayListWithCapacity(groupInputSpec.getGroupVertices().size()); for (String groupVertex : groupInputSpec.getGroupVertices()) { inputs.add(inputsMap.get(groupVertex)); } MergedLogicalInput groupInput = (MergedLogicalInput) createMergedInput(groupInputSpec.getMergedInputDescriptor(), mergedInputContext, inputs); groupInputsMap.put(groupInputSpec.getGroupName(), groupInput); } } }