What is LE mean in istio metric "istio_response_bytes_bucket"?

Question

I'm newbie about istio. I wonder what is the meaning of "le" which is in the "istio_response_bytes_bucket" istio metric. Could anyone let me know the meaning or where is references?

istio_response_bytes_bucket{response_code="200",reporter="destination",...,le="500"} 0

Answer 1

It seems that LE stands for "Less than and Equal".

So istio_response_bytes_bucket{...le="500"} 0 metric means that count of request which's response's bytes is less than and equal to 500 is 0.

https://prometheus.io/docs/concepts/metric_types/#histogram