The SHARP Tree in Super Pod Networking

In Super Pod networking, if the last SU has less than 32 nodes, such as only 16 nodes, then the last SU’s Leaf switch can use only 4 switches. This can save the number of switches and costs, but it will sacrifice some network performance and reliability.

SHARP tree is a topology structure based on multi-layer switches, which can achieve efficient global aggregation and broadcast. The construction of SHARP tree requires the following conditions:

• Each node has two network cards, which are connected to different Leaf switches.
• Each Leaf switch has two uplink ports, which are connected to different Spine switches.
• Each Spine switch has two downlink ports, which are connected to different Leaf switches.

If the two network cards of the same node are connected to the same Leaf switch, then the SHARP tree cannot meet the above conditions, and the following problems will occur:

• Network redundancy is reduced. If the Leaf switch or its uplink port fails, the node will lose network connection.
• Network bandwidth is reduced. Because each node can only use the bandwidth of one network card, instead of the aggregated bandwidth of two network cards.
• Network latency is increased. Because the communication between each node may need to go through more hops.

Therefore, if you want to use SHARP tree as the topology structure of Super Pod networking, it is recommended that the two network cards of each node are connected to different Leaf switches, to ensure network performance and reliability.