Alert always update Active Since date to current time and cant fire

[Teriand]

Bug Report

What did you do?
After upgrade 2.3.2 ->2.4.2
Alert always update Active Since date to current time and cant fire:

ex on screen
alert: IgnoreAlert
expr: vector(1)
for: 10s

cant fire. Before update i use him for tesing and it fire work.
"Active Since" always set after refresh page to current time.
or
curl http://localhost:9090/api/v1/alerts

,{"labels":{"alertname":"IgnoreAlert","grafana":"http://prometheus-01:3000?from=1537865257060\u0026to=1537868857060","severity":"warn","type":"test","zone":"test"},"annotations":{"description":"Daily alert test description","summary":"Daily alert test summary http://prometheus-01:3000/d/000000011/windows-node-test-stands?refresh=10s\u0026orgId=1\u0026var-interval=60s\u0026var-server=auto-fna-62\u0026from=now-3h\u0026to=now"},"state":"pending","activeAt":"2018-09-25T12:17:37.060655984+03:00","value":1}]}}

What did you expect to see?
Change Pending to Fire state

What did you see instead? Under which circumstances?
Persist Pending state

Environment

• System information:

Linux 4.1.12-61.1.18.el7uek.x86_64 x86_64

• Prometheus version:
  prometheus, version 2.4.2 (branch: HEAD, revision: c305ffa)
  build user: root@dcde2b74c858
  build date: 20180921-07:22:29
  go version: go1.10.3

• Prometheus configuration file:

global:
  scrape_interval:     15s
  evaluation_interval: 15s
  scrape_timeout: 15s
alerting:
  alertmanagers:
  - static_configs:
    - targets: ['prometheus-01:9093']
rule_files:
   - "test-alert.yml"
scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['prometheus-01:9090']
    metric_relabel_configs:
      - source_labels: [ __name__ ]
        regex: 'go_(.*)'
        action: drop

[simonpasquier]

This is because your grafana label value is changing everytime Prometheus evaluates the alert. It was a bug (#4169) in the alerting code and it has been fixed in 2.4.x. You should store this value as an annotation instead.

[Teriand]

but #4169 closed and #4500 merget, next #4571 track it ?

ps
move grafana from labels to annotations work fine. thx

[simonpasquier]

#4571 can be closed too if it is really a duplicate of #4169.

[Teriand]

and mb open my issue to track fix alerting code in 2.4.x?

[simonpasquier]

I'm not sure to understand your last question but there's no bug to be fixed. The alert's identity is defined by its labels. If the labels aren't constant over time then they are different alerts.

[Teriand]

ok, i mistake u message: " It was a bug (#4169) in the alerting code and it has been fixed in 2.4.x."
I change all my alert-rule files for annotatons.
thx.