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Prometheus can collect metric from 1 pod when Prometheus can reach the pod to scrape metrics. But this setup will not be able to tell how many pods are ready. This is when scraping directly from pod is done via Kubernetes service. This causes a false positive when Prometheus scrapes directly from the pod. With this topology, prometheus can reach all the pods and the up metric of each pod will have the value 1, even when the pods are not in the ready state or their readiness probes are failed.