Systems and methods for supporting target groups for congestion control in a private fabric in a high performance computing environment. An exemplary method can provide, at one or more microprocessors, a first subnet, the first subnet comprising a plurality of switches, a plurality of host channel adapters, and a plurality of end nodes, including a plurality of virtual machines. The method can define a target group on one of an inter-switch link or at a port of a switch of the plurality of switches, wherein the target group defines a bandwidth limit on the at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches. The method can provide a target group repository stored in a memory of the host channel adapter where the defined target group in the target group repository is recorded.

A data exchange method and apparatus. The method includes: A source node receives flow indication information from a first switching node, where the flow indication information indicates that congestion occurs in a target data flow, and the first switching node is a node in a switching path of the target data flow. The source node sends multiple pieces of write data information and multiple data blocks of the target data flow to multiple switching nodes, where the multiple pieces of write data information indicate the multiple switching nodes to store the multiple data blocks and stop forwarding the multiple data blocks. The multiple switching nodes store the multiple data blocks. The multiple switching nodes receive multiple pieces of scheduling information from a destination node, where the multiple pieces of scheduling information are used to schedule the multiple data blocks.

A data exchange method and apparatus. The method includes: A source node receives flow indication information from a first switching node, where the flow indication information indicates that congestion occurs in a target data flow, and the first switching node is a node in a switching path of the target data flow. The source node sends multiple pieces of write data information and multiple data blocks of the target data flow to multiple switching nodes, where the multiple pieces of write data information indicate the multiple switching nodes to store the multiple data blocks and stop forwarding the multiple data blocks. The multiple switching nodes store the multiple data blocks. The multiple switching nodes receive multiple pieces of scheduling information from a destination node, where the multiple pieces of scheduling information are used to schedule the multiple data blocks.