[Scalability] Enable Horizontal Pod Autoscaler (HPA) for Alcor deployment

kubernetes/services/vpc_manager_hpa.yaml

@@ -10,6 +10,26 @@ spec:
   # if minReplicas is less than Deployment replicas value, it may cause scale down
   minReplicas: 5
   maxReplicas: 10
+  behavior:
+    scaleDown:
+      # Indicates that the stability window considers the expected state of the past (here within 300 sec) to prevent expansion and contraction
+      stabilizationWindowSeconds: 300
+      policies:
+        - type: Percent
+          value: 100
+          periodSeconds: 15
+      # The autoscaler will choose the strategy that affects the minimum number of Pods
+      selectPolicy: Min
+    scaleUp:
+      stabilizationWindowSeconds: 0
+      policies:
+        - type: Percent
+          value: 100
+          periodSeconds: 15
+        - type: Pods
+          value: 4
+          periodSeconds: 15
+      selectPolicy: Max
   metrics:
 #   Set the average usage rate of the cpu, scale up if it exceeds 50
     - type: Resource

services/vpc_manager/src/main/java/com/futurewei/alcor/vpcmanager/controller/VpcController.java

@@ -429,4 +429,20 @@ public VpcWebJson deleteSubnetIdInVpcState(@PathVariable String projectid, @Path
         return new VpcWebJson(inVpcState);
 
     }
+
+    @RequestMapping(
+            method = GET,
+            value = {"/hpatest"})
+    @DurationStatistics
+    public double hpaTest() throws Exception {
+
+        double res = 0.001;
+
+        for (int i = 0; i < 100000; i ++) {
+            res += res * res;
+        }
+
+        return res;
+
+    }
 }