Merge pull request #113512 from mlearned/mdl-1710708-max-pods

Mdl 1710708 max pods

Author: PRMerger17

articles/aks/configure-azure-cni.md

@@ -63,7 +63,9 @@ The maximum number of pods per node in an AKS cluster is 250. The *default* maxi
 
 ### Configure maximum - new clusters
 
-You're able to configure the maximum number of pods per node *only at cluster deployment time*. If you deploy with the Azure CLI or with a Resource Manager template, you can set the maximum pods per node value as high as 250.
+You're able to configure the maximum number of pods per node at cluster deployment time or as you add new node pools. If you deploy with the Azure CLI or with a Resource Manager template, you can set the maximum pods per node value as high as 250.
+
+If you don't specify maxPods when creating new node pools, you receive a default value of 30 for Azure CNI.
 
 A minimum value for maximum pods per node is enforced to guarantee space for system pods critical to cluster health. The minimum value that can be set for maximum pods per node is 10 if and only if the configuration of each node pool has space for a minimum of 30 pods. For example, setting the maximum pods per node to the minimum of 10 requires each individual node pool to have a minimum of 3 nodes. This requirement applies for each new node pool created as well, so if 10 is defined as maximum pods per node each subsequent node pool added must have at least 3 nodes.
 
@@ -81,7 +83,7 @@ A minimum value for maximum pods per node is enforced to guarantee space for sys
 
 ### Configure maximum - existing clusters
 
-You can't change the maximum pods per node on an existing AKS cluster. You can adjust the number only when you initially deploy the cluster.
+The maxPod per node setting can be defined when you create a new node pool. If you need to increase the maxPod per node setting on an existing cluster, add a new node pool with the new desired maxPod count. After migrating your pods to the new pool, delete the older pool. To delete any older pool in a cluster, ensure you are setting node pool modes as defined in the [system node pool document[system-node-pools].
 
 ## Deployment parameters
 
@@ -208,3 +210,4 @@ Kubernetes clusters created with AKS Engine support both the [kubenet][kubenet]
 [network-policy]: use-network-policies.md
 [nodepool-upgrade]: use-multiple-node-pools.md#upgrade-a-node-pool
 [network-comparisons]: concepts-network.md#compare-network-models
+[system-node-pools]: use-system-pools.md

articles/aks/configure-kubenet.md

@@ -12,7 +12,7 @@ ms.reviewer: nieberts, jomore
 
 By default, AKS clusters use [kubenet][kubenet], and an Azure virtual network and subnet are created for you. With *kubenet*, nodes get an IP address from the Azure virtual network subnet. Pods receive an IP address from a logically different address space to the Azure virtual network subnet of the nodes. Network address translation (NAT) is then configured so that the pods can reach resources on the Azure virtual network. The source IP address of the traffic is NAT'd to the node's primary IP address. This approach greatly reduces the number of IP addresses that you need to reserve in your network space for pods to use.
 
-With [Azure Container Networking Interface (CNI)][cni-networking], every pod gets an IP address from the subnet and can be accessed directly. These IP addresses must be unique across your network space, and must be planned in advance. Each node has a configuration parameter for the maximum number of pods that it supports. The equivalent number of IP addresses per node are then reserved up front for that node. This approach requires more planning, and often leads to IP address exhaustion or the need to rebuild clusters in a larger subnet as your application demands grow.
+With [Azure Container Networking Interface (CNI)][cni-networking], every pod gets an IP address from the subnet and can be accessed directly. These IP addresses must be unique across your network space, and must be planned in advance. Each node has a configuration parameter for the maximum number of pods that it supports. The equivalent number of IP addresses per node are then reserved up front for that node. This approach requires more planning, and often leads to IP address exhaustion or the need to rebuild clusters in a larger subnet as your application demands grow. You can configure the maximum pods deployable to a node at cluster create time or when creating new node pools. If you don't specify maxPods when creating new node pools, you receive a default value of 110 for kubenet.
 
 This article shows you how to use *kubenet* networking to create and use a virtual network subnet for an AKS cluster. For more information on network options and considerations, see [Network concepts for Kubernetes and AKS][aks-network-concepts].
 

articles/aks/use-system-pools.md

@@ -46,6 +46,7 @@ You can do the following operations with node pools:
 * Delete user node pools.
 * You can delete system node pools, provided you have another system node pool to take its place in the AKS cluster.
 * An AKS cluster may have multiple system node pools and requires at least one system node pool.
+* If you want to change various immutable settings on existing node pools, you can create new node pools to replace them. One example is to add a new node pool with a new maxPods setting and delete the old node pool.
 
 ## Create a new AKS cluster with a system node pool