When instrumenting metrics using OpenTelemetry Python 0.44b0 and exporting them using opentelemetry-exporter-prometheus when using multiprocessing, not all metrics are exposed on the metrics endpoint.
I assume that this comes from the underlying limitation from prometheus_client, which states that multiprocess mode does not work with custom collectors. It could be worth mentioning this limitation in the Prometheus exporter docs.
Steps to reproduce
Raise metrics in multiprocessing mode when having the Prometheus exporter enabled
Not all metrics are exposed on Prometheus endpoint
What is the expected behavior?
All raised metrics are exposed on the Prometheus endpoint.
What is the actual behavior?
Not all metrics are exposed on the Prometheus endpoint.
Describe your environment
When instrumenting metrics using OpenTelemetry Python 0.44b0 and exporting them using
opentelemetry-exporter-prometheus
when using multiprocessing, not all metrics are exposed on the metrics endpoint.I assume that this comes from the underlying limitation from prometheus_client, which states that multiprocess mode does not work with custom collectors. It could be worth mentioning this limitation in the Prometheus exporter docs.
Steps to reproduce
What is the expected behavior?
All raised metrics are exposed on the Prometheus endpoint.
What is the actual behavior?
Not all metrics are exposed on the Prometheus endpoint.