Promql filter out time series with value in label same like in another metric dynamicaly

Question

Assuming I have two different metrics with different labels names but the same a group of values :

metric1{label1="some_values_the_same_as_in_metric2"}  val examples: val1 val2 val3
metric2{label2="some_values_the_same_as_in_metric1"}  val examples: val2 val3 

Now I want to query metric1 with label1 but filter out all metrics with the same value as in metric2 label2

I know I can metric1{label1!=~"val2|val3"}

but what if i have 300 values in metric1 and 200 in metric2 and these can change over time? how to filter it out dynamically?

tried many things like this: metric_name1 unless metric_name2 on(common_label) group_left but without success

Answer 1

Your attempt is in correct direction. It's just that on() clause needs label common for both metrics, but based on your example, they are not.

This is not a problem though: label_replace can help us here.

metric_name1
 unless on(label1)
 label_replace(metric_name2, "label1", "$1", "label2", "(.*)")

Here, I copy label label2 into label1, and then use it in unless to exclude all the metrics with matching label1.

You don't need group_left since unless with on clause doesn't change left operand's labels set (unlike and with on clause).