Add behavior for Horizontal Pod Autoscaler (#366)

* Add behavior for hpa

* Evaluate autoscaling by CPU and memory separately

* Add PASSENGER_MAX_POOL_SIZE env var for web-api

* Fix possition for PASSENGER_MAX_POOL_SIZE env var

Author: Rub21

osm-seed/templates/web/web-deployment.yaml

@@ -168,6 +168,8 @@ spec:
             - name: CGIMAP_PORT
               value: {{ quote 8000 }}
             {{- end }}
+            - name: PASSENGER_MAX_POOL_SIZE
+              value: {{ .Values.web.env.PASSENGER_MAX_POOL_SIZE | default "6" | quote }}
           volumeMounts:
             - mountPath: /dev/shm
               name: shared-memory

osm-seed/templates/web/web-hpa.yaml

@@ -11,16 +11,33 @@ spec:
   minReplicas: {{ .Values.web.autoscaling.minReplicas }}
   maxReplicas: {{ .Values.web.autoscaling.maxReplicas }}
   metrics:
-  - type: Resource
-    resource:
-      name: cpu
-      target:
-        type: Utilization
-        averageUtilization: {{ .Values.web.autoscaling.cpuUtilization }}
-  - type: Resource
-    resource:
-      name: memory
-      target:
-        type: Utilization
-        averageUtilization: {{ .Values.web.autoscaling.memoryUtilization }}
+    {{- if .Values.web.autoscaling.cpuUtilization.enable }}
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: {{ .Values.web.autoscaling.cpuUtilization.value }}
+    {{- end }}
+    {{- if .Values.web.autoscaling.memoryUtilization.enable }}
+    - type: Resource
+      resource:
+        name: memory
+        target:
+          type: Utilization
+          averageUtilization: {{ .Values.web.autoscaling.memoryUtilization.value }}
+    {{- end }}
+  behavior:
+    scaleUp:
+      stabilizationWindowSeconds: {{ .Values.web.autoscaling.behavior.scaleUp.stabilizationWindowSeconds | default 60 }}
+      policies:
+        - type: Percent
+          value: {{ .Values.web.autoscaling.behavior.scaleUp.policyValue | default 100 }}
+          periodSeconds: {{ .Values.web.autoscaling.behavior.scaleUp.periodSeconds | default 60 }}
+    scaleDown:
+      stabilizationWindowSeconds: {{ .Values.web.autoscaling.behavior.scaleDown.stabilizationWindowSeconds | default 60 }}
+      policies:
+        - type: Percent
+          value: {{ .Values.web.autoscaling.behavior.scaleDown.policyValue | default 50 }}
+          periodSeconds: {{ .Values.web.autoscaling.behavior.scaleDown.periodSeconds | default 60 }}
 {{- end }}

osm-seed/values.yaml

@@ -162,6 +162,7 @@ web:
     RAILS_STORAGE_REGION: us-east-1
     RAILS_STORAGE_BUCKET: osmseed-website-bucket
     EXTERNAL_CGIMAP: false
+    PASSENGER_MAX_POOL_SIZE: 6
   resources:
     enabled: false
     requests:
@@ -175,11 +176,24 @@ web:
   nodeSelector:
     enabled: false
   autoscaling:
-    enabled: false
+    enabled: true
     minReplicas: 1
-    maxReplicas: 3
-    cpuUtilization: 60
-    memoryUtilization: 60
+    maxReplicas: 6
+    cpuUtilization:
+      enable: false
+      value: 85
+    memoryUtilization:
+      enable: false
+      value: 85
+    behavior:
+      scaleUp:
+        stabilizationWindowSeconds: 60
+        policyValue: 100
+        periodSeconds: 60
+      scaleDown:
+        stabilizationWindowSeconds: 60
+        policyValue: 50
+        periodSeconds: 60
   sharedMemorySize: 256Mi
   livenessProbeExec: true
 # ====================================================================================================