The best option for selecting a deployment and testing strategy that meets your requirements is to use blue
/green deployment and canary testing. A blue/green deployment is a deployment strategy that involves creating two identical environments, one running the current version of the application (blue) and one running the new version of the application (green). The traffic is switched from blue to green after testing the new version, and if any issues are discovered, the traffic can be switched back to blue instantly. This way, you can reduce the complexity of release deployments and minimize the duration of deployment rollbacks. A canary testing is a testing strategy that involves releasing a new version of an application to a subset of users or servers and monitoring its performance and reliability. This way, you can test real production traffic with a gradual increase in the number of affected users.

Creating a development environment for writing code and a test environment for configurations, experiments, and load testing is the best practice to reduce the number of bugs and outages in production and to enable testers to load test new features. This way, the production environment is isolated from changes that could affect its stability and performance.

Comprehensive and Detailed Explanation:
Cloud Run scales down to zero when idle. If CPU is allocated only during request processing, background telemetry tasks (like OpenTelemetry traces) may not complete before the container shuts down.
Solution: Configure CPU to be always-allocated # This ensures that background tasks (like trace exports) continue even when the service is idle.
#Why not other options?
A (Increasing CPU to 4 cores)## More CPU won't help if traces are being cut off due to shutdown.
B (Using an HTTP health check)## Doesn't affect OpenTelemetry traces.
C (CPU only during request processing)## This causes the problem because traces need CPU after request completion to be exported.
#Official Reference:
Cloud Run Tracing with OpenTelemetry
Cloud Run Always-Allocated CPU

https://cloud.google.com/compute/docs/instances/preemptible