Remote read adding external labels might lead to unsorted response #12605
Description
What did you do?
/api/v1/read is supposed to always give a sorted series set as a response. Consider the following:
External labels are region: foo.
Series without any external labels:
aaa{instance="bbb", job="etcd-prometheus-exporter", service="etcd-prometheus-exporter", toposphere="test1"} 1
aaa{instance="bbb", job="etcd-prometheus-exporter", region="bar", service="etcd-prometheus-exporter", toposphere="test1"} 0
aaa{instance="bbb", job="etcd-prometheus-exporter", region="bar", service="etcd-prometheus-exporter", toposphere="test2"} 0
aaa{instance="bbb", job="etcd-prometheus-exporter", region="foo", service="etcd-prometheus-exporter", toposphere="test1"} 1
aaa{instance="bbb", job="etcd-prometheus-exporter", region="foo", service="etcd-prometheus-exporter", toposphere="test2"} 1
prometheus/storage/remote/codec.go
Line 230 in 03e549c
region: foo if it does not exist while iterating.
What did you expect to see?
I expected to see an error? that the response cannot contain the same label set. Not sure, though.
What did you see instead? Under which circumstances?
The result is the following:
aaa{instance="bbb", job="etcd-prometheus-exporter", region="foo", service="etcd-prometheus-exporter", toposphere="test1"} 1
aaa{instance="bbb", job="etcd-prometheus-exporter", region="bar", service="etcd-prometheus-exporter", toposphere="test1"} 0
aaa{instance="bbb", job="etcd-prometheus-exporter", region="bar", service="etcd-prometheus-exporter", toposphere="test2"} 0
aaa{instance="bbb", job="etcd-prometheus-exporter", region="foo", service="etcd-prometheus-exporter", toposphere="test1"} 1
aaa{instance="bbb", job="etcd-prometheus-exporter", region="foo", service="etcd-prometheus-exporter", toposphere="test2"} 1
System information
No response
Prometheus version
No response
Prometheus configuration file
No response
Alertmanager version
No response
Alertmanager configuration file
No response
Logs
No response