<p>I'm relatively new to K8's, and I've setup a private cluster with a single node pool on GKE. The node pool was configured to have nodes on 3 zones in a single GCP region (Autoscaling enabled with minimum of 2 nodes and maximum of 20 total nodes).</p>
<p>I ran into the following error upon trying to deploy new resources: <code>Cannot schedule pods: Insufficient memory.</code> I decided to disable Autoscaling on cluster's node pool, and then manually increase the number of nodes. I applied the change, each Instance Group now has 3 instances (a total of 9). However, the instances listed under the 'Nodes' section of the GKE Console does not reflect that. It show only 5 (which is actually a decrease from the original 6).</p>
<p><a href="https://i.stack.imgur.com/ZSsC5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZSsC5.png" alt="enter image description here" /></a></p>
<p>GCP DOCS:
<a href="https://cloud.google.com/kubernetes-engine/docs/how-to/resizing-a-cluster" rel="nofollow noreferrer">https://cloud.google.com/kubernetes-engine/docs/how-to/resizing-a-cluster</a></p>
<p>What am I missing here? Thanks</p>

bahmsto
<p>The problem here was caused by mismatch between versions of the cluster and node pool.</p>
<blockquote>
<p>By default, <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/cluster-upgrades#upgrading_automatically" rel="nofollow noreferrer">automatic upgrades</a> are enabled for Google Kubernetes Engine (GKE) clusters and node pools.</p>
</blockquote>
<p><a href="https://cloud.google.com/kubernetes-engine/docs/how-to/upgrading-a-cluster#upgrading-nodes" rel="nofollow noreferrer">Here</a> is documentation that helps to upgrade cluster or node pool manually.</p>
<hr />
<p>Upgrading to the default cluster version can be done by running the following command:</p>
<pre><code>gcloud container clusters upgrade CLUSTER_NAME --master
</code></pre>
<hr />
<p>All nodes can be updated to the same version as the control plane by running this command:</p>
<pre><code>gcloud container clusters upgrade
</code></pre>
<p>Following command should be used in case rolling back an upgrade:</p>
<pre><code>gcloud container node-pools rollback NODE_POOL_NAME \  --cluster CLUSTER_NAME
</code></pre>
<hr />
<p>See also <a href="https://cloud.google.com/sdk/gcloud/reference/container/clusters/upgrade" rel="nofollow noreferrer">this reference</a> and <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/cluster-upgrades#how_cluster_and_node_pool_upgrades_work" rel="nofollow noreferrer">this documentation</a>.</p>
