Gke Cluster Lifecycle

2. Configure Surge Upgrades

Surge upgrades allow you to specify how many nodes can be created above the target size during an upgrade, minimizing disruption.

Example configuration:

gcloud container node-pools update <pool-name> \
    --cluster=<cluster-name> \
    --max-surge-upgrade=2 \
    --max-unavailable-upgrade=0 \
    --region <region>

Setting max-unavailable-upgrade=0 ensures that no nodes are taken offline before new ones are ready.

3. Implement Blue/Green Node Pool Upgrades

For high-risk upgrades, you can create a new node pool (Green) with the new version, test it, and then migrate workloads from the old node pool (Blue).

Steps:

1. Create a new node pool with the new version and appropriate taints (using --node-taints).
2. Cordon and drain the old node pool gradually.
3. Delete the old node pool once empty.

Best Practices

1. Use Release Channels: Always enroll production clusters in a release channel (preferably Stable or Regular).
2. Configure Surge Upgrades: Use max-surge-upgrade to ensure availability during upgrades.
3. Use Maintenance Windows: Configure maintenance windows to ensure upgrades only happen during off-peak hours (see gke-reliability).
4. Test in Non-Prod: Always test upgrades in a staging environment before applying them to production.