Software-Defined Network Resource Optimization of the Data Center Based on P4 Programming Language

Algorithm 1

The algorithm flow.

	Step 1. Receive a migration request (5-tuple).
	Step 2. Establish a QoS flow migration queue. According to the online migration model, the three streams of mirror file, memory copy, and shutdown copy are added to the migration queue.
	Step 3. Process each flow in the migration queue. First, calculate the weights of all links in the current network by formula (2).
	Step 4. Use the Dijkstra algorithm to calculate the minimum cost path rc, according to formula (4), if fD(r) < Dmax, then tC is the optimal path, which is used as the path to transmit the current stream; otherwise, jump to step 5.
	Step 5. Use the Dijkstra algorithm to calculate the minimum delay path rd from s to d. If rd does not exist, use rc as an alternative path. If there is, proceed to step 6.
	Step 6. Let
	Recalculate the joint weight for each link
	Step 7. Recalculate the minimum cost path r from s to d. If , then is the optimal path. Otherwise, let and go to step 6 to recalculate.