Cold start latency in IBM Cloud Code Engine scale-to-zero workloads

Scaling to Zero for Low-Traffic Workloads

IBM Cloud Code Engine provides a serverless execution environment that can scale applications down to zero active instances during periods of inactivity. This mechanism is intended to eliminate compute costs when no requests are being processed, transitioning the workload to a request-based consumption model.

Resource Constraints and Startup Latency

While scaling to zero optimizes costs, it introduces a "cold start" phenomenon. When the first request arrives after a scale-to-zero event, the platform must provision the container and initialize the application before the request can be served. There is uncertainty regarding how the defined CPU and memory resource limits specifically correlate with the duration of this startup latency.

For time-sensitive applications, the trade-off between cost savings and initial response time is critical. It is unclear if there are platform-level configurations to optimize the image pull or container initialization phase without increasing the minimum instance count to one.

• How do different CPU and memory resource allocations impact the cold start duration in Code Engine?
• Are there specific image optimization strategies that measurably reduce the latency observed during a scale-from-zero event?