I deployed a EventBus to AWS EventBridge with a few rules. According to EventBridge limits https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-quota.html, there is one limit Invocations throttle limit in transactions per second which is different for different regions.

My question is that which metric I can use to monitor the usage? Is the metric on EventBus level or on rule level? I have checked a few metrics, Invocations, TriggeredRule but their value is not really the actual usage of the event bridge. What is the right metric I should look at?