Before you add a label

Before you add a label to a metric, ask yourself three quick questions.

First, will anyone aggregate or filter by it? If nobody queries by this dimension, it’s pure cost.

Second, is the value set bounded? Think tens of values, not thousands.

Third, how does it multiply? A new label doesn’t exist in isolation, so check it against the labels already on the metric. Three bounded labels can still combine into thousands of series.