NOVA Views in *GRAPH

Communication Step NOVA

Line angle = Communication step number.
Line length = Data bytes transfered for that step (scaled display).

The top 3 NOVA views ( Cyan, Magenta, Pink ) show communication in a parallel program at each communication step: The Cyan NOVA displays the sum of Send + Receive Bytes for each communication step. The Magenta and Pink NOVAs display the number of bytes at the hot send node and hot receive node , respectively, for each communication step. The user-selected communication step is highlighted as a yellow line.

Source Code Window

In the source code window, the highlighted statement corresponds to the user-selected communication step. Thus a user can pinpoint the source code statement corresponding to a communication bottleneck by selecting the longest line in a Program Step NOVA.

Parallel Node NOVA

Line angle = Node number.
Line length = Data bytes sent or received at that node for the selected step (scaled display).

The bottom 2 NOVA views ( Yellow ) show how communication at the selected step is distributed across the parallel nodes for sends and receives . Symmetric NOVA patterns indicate equal traffic at all nodes. Asymmetric NOVA patterns can be used to locate hot spot nodes, where the longest lines indicate which nodes are hot spots for the selected step.