Fix rolling update of istiod

Change-Id: Iac9b251d99d6c4487b5b2e0d78425fc517a5d39b
diff --git a/istio/src/istiod-deployment.yaml b/istio/src/istiod-deployment.yaml
index d982ce1..54568d6 100755
--- a/istio/src/istiod-deployment.yaml
+++ b/istio/src/istiod-deployment.yaml
@@ -9,14 +9,14 @@
   name: istiod
   namespace: istio-system
 spec:
-  replicas: 1
+  replicas: 2
   selector:
     matchLabels:
       istio: pilot
   strategy:
     rollingUpdate:
       maxSurge: 100%
-      maxUnavailable: 25%
+      maxUnavailable: 50%
   template:
     metadata:
       annotations:
diff --git a/istio/src/istiod-hpa.yaml b/istio/src/istiod-hpa.yaml
index e85f03e..33d020c 100755
--- a/istio/src/istiod-hpa.yaml
+++ b/istio/src/istiod-hpa.yaml
@@ -18,7 +18,7 @@
       name: cpu
       targetAverageUtilization: 80
     type: Resource
-  minReplicas: 1
+  minReplicas: 2
   scaleTargetRef:
     apiVersion: apps/v1
     kind: Deployment