For the second year of the Ohm Project (9/20001-8/2002), we will reconfigure Ohm to use a ring-star hybrid topology. The following diagram depicts this topology, with the new network links shown in red, the 'master' nodes shown in light blue, and the 'server' nodes shown in dark blue:

To implement this topology, two new network interface cards (NICs) will be added to each node, supplementing the NIC used in year 1. Each node's routing tables will also be reconfigured so that:

• packets to a node's one neighbor in the ring are directed to the NIC for that neighbor,
• packets to the node's other neighbor in the ring are directed to the NIC for that neighbor, and
• packets to any other node are directed to the NIC for the switch.

After collecting performance data in this configuration for six months, the cluster's topology will be altered to its year 3 (final) form.