Automatic Scaling Mechanism of Intermodal EDI System under Green Cloud Computing

Algorithm 2

XEDI’s automatic shrinkage algorithm.

	name: autoScalingDown
	input: C: XEDI performance context;
	output: none
	//If the XEDI resource occupancy rate is low, it will not shrink, reducing the number of
	//unnecessary shrinkages
	if () { terminate scaling-down;}
	//Get all the POD sets for XEDI
	retrieve all pods of XEDI from K8S as collection<POD>;
	for (POD pod: collection<POD>) {
	retrieve pod. C;
	//Avoid frequent POD scaling by cooling-off time
	if (currentTime-pod. lastScalingTime < pod. C. ) {
	enter next loop;
	}
	/^∗Calculate POD expansion index^∗/
	If (scalingStrategy == 0) {
	//According to formulas (2) and (3), qi = 1, the response capacity expansion index based
	//on mixed load rate was calculated
	;
	} else {
	//According to formulas (5)–(7), the predictive expansion index was calculated
	;
	}
	//Adjust pods with lower load rates
	if (() {
	//Reduce the number of copies of POD according to the flex index
	pod. replicas = ^∗I;
	//Refresh the POD’s copy number configuration so that the POD’s shrinkage takes effect
	refresh pod replication for K8S with XTuning. Scheduler;
	}
	//Stop shrinking when the resource utilization rate falls below the resource load rate
	if () { terminate scaling-down;}
	}