What method should be used for executing a phased rollout to half of the web server pods in Google Kubernetes Engine?

Using a partitioned rolling update is the most appropriate method for executing a phased rollout to half of the web server pods in Google Kubernetes Engine. This approach allows you to gradually update a subset of your pods, providing control over the deployment process and enabling you to monitor the impact of changes before fully rolling them out.

Partitioned rolling updates facilitate the deployment by specifying a certain percentage of pods that can be updated at each step. This is advantageous in minimizing disruptions, as it helps ensure that at least half of the pods remain operational and can serve traffic while the others are being updated. This staged approach is particularly useful for mitigating risk by allowing for quick rollbacks if issues arise during the upgrade.

The other options do not align with the goal of a phased rollout as effectively. Node taints with NoExecute are primarily used for controlling pod scheduling based on node conditions and do not directly relate to managing the rollout of updates across pods. A replica set in the deployment specification pertains more to maintaining the desired number of pod replicas rather than rolling out updates in a controlled manner. Meanwhile, a stateful set with parallel pod management policy is designed for stateful applications that require stable network identities and persistent storage rather than handling updates to stateless applications in a phased fashion.