Dragon Overlay Network

In the multi-node case, Dragon establishes an Overlay Network to communicate between the Dragon Launcher FrontEnd and the Dragon Launcher Backend processes running on each backend compute node. To establish this Overlay Network, Dragon uses the Dragon TCP Network Agent in a Fanout Tree. The Fanout Tree uses a default branching factor of 32 nodes. The hierarchy of the tree follows the order of nodes in the node list with the root being the front end and children being located at bn+1 to bn+b where b is the branching factor (32) of the tree. This enables Dragon to scale and communicate with a large number of nodes efficiently.

Fig. 48 shows an example of a 10,000 node Dragon Overlay Network Fanout.

../_images/overlay_network_fanout.svg

Fig. 48 Example 10,000 node Overlay Network fanout