Prometheus and ELK (Elastic Search, Logstash, Kibana) are similar tools used to gather, display, and analyze data. This is sometimes referred to a "scraping metrics". For example, both Prometheus and ELK can be used to display data about servers, virtual machines (VMs), databases, containers (e.g. Docker, OpenShift), messaging (e.g. IBM MQ, RabbitMQ), and the list goes on.

Often, Prometheus or ELK send alerts to some other system, such as Alert Manager and then Alert Manager would route alerts to certain targets, such as an SMTP email server or OpsGenie.

The oc get pods command can be used to list the Prometheus pods, often in the openshift-monitoring namespace.

~]$ oc get pods --namespace openshift-monitoring
NAME                                                     READY   STATUS    RESTARTS        AGE
prometheus-adapter-6b98c646c7-m4g76                      1/1     Running   0               8d
prometheus-adapter-6b98c646c7-tczr2                      1/1     Running   0               8d
prometheus-k8s-0                                         6/6     Running   0               11d
prometheus-k8s-1                                         6/6     Running   0               11d
prometheus-operator-6766f68555-mkfv9                     2/2     Running   0               11d
prometheus-operator-admission-webhook-8589888cbc-mq2jx   1/1     Running   0               11d
prometheus-operator-admission-webhook-8589888cbc-t62mt   1/1     Running   0               11d

The oc exec and curl commands can be used to issue a POST request inside of your Prometheus pod to the /-/reload to reload Prometheus configurations.

oc exec prometheus-k8s-0 --container prometheus --namespace openshift-monitoring -- curl --request POST --url http://localhost:9090/-/reload