question: private Map < UUID , Collection < HadoopInputSplit > > mappers ( Collection < ClusterNode > top , Collection < UUID > topIds , Iterable < HadoopInputSplit > splits ) throws IgniteCheckedException { Map < UUID , Collection < HadoopInputSplit > > mappers = new HashMap < > ( ) ; Map < String , Collection < UUID > > nodes = groupByHost ( top ) ; Map < UUID , Integer > nodeLoads = new HashMap < > ( top . size ( ) , 1.0f ) ; for ( UUID nodeId : topIds ) nodeLoads . put ( nodeId , 0 ) ; for ( HadoopInputSplit split : splits ) { UUID nodeId = nodeForSplit ( split , topIds , nodes , nodeLoads ) ; if ( log . isDebugEnabled ( ) ) log . debug ( "Mapped split to node [split=" + split + ", nodeId=" + nodeId + ']' ) ; Collection < HadoopInputSplit > nodeSplits = mappers . get ( nodeId ) ; if ( nodeSplits == null ) { nodeSplits = new ArrayList < > ( ) ; mappers . put ( nodeId , nodeSplits ) ; } nodeSplits . add ( split ) ; nodeLoads . put ( nodeId , nodeLoads . get ( nodeId ) + 1 ) ; } return mappers ; }
target:  Create plan for mappers.