To minimize the setup effort for monitoring application-level metrics on GKE, what should you implement?

Implementing the OpenTelemetry client libraries in the application is an effective way to minimize the setup effort for monitoring application-level metrics on Google Kubernetes Engine (GKE). OpenTelemetry provides a standardized framework for collecting, processing, and exporting observability data, including metrics, traces, and logs. By using these libraries, developers can automatically collect metrics from their applications with minimal code changes.

The OpenTelemetry client libraries simplify the integration process because they are designed to handle various aspects of observability, such as context propagation and configuration management. This allows teams to focus on writing code while the libraries take care of collecting and exporting the metrics to the chosen backend, such as Google Cloud Monitoring. Furthermore, configuring export destinations can be done easily to direct metrics to Cloud Monitoring, which can visualize and alert on this data without extensive manual setup.

In contrast, directly publishing metrics to the Cloud Monitoring API requires a deep understanding of the function and format of the API, leading to more overhead for developers. Using Cloud Pub/Sub would require additional components for messaging, which adds complexity. Emitting metrics as log messages is less efficient for metric analysis, as logs are typically not structured for metrics, making it harder to query and visualize the data effectively. Thus, utilizing OpenTelemetry strikes a balance