Strange behaviour of silences.expired

Question/bug 1: why should the alert be older than the silences.expired duration ?

Because the goal is to tell you why you suddenly see an alert, and so that you know there's likely no point debugging it as this is an old issue that was silenced but the silence just expired.
Duration requirement exists to only show the silence where it's relevant - when it's something you likely don't know about, rather than show you all silences ever linked to given alert. If both alert and silence are recent then you're likely to be the one silencing and so you know about it.

Question/bug 2: At 10h07 I could not see the 1st silence. Why can I see it now (I can see the 2 silences now) ?

Because at 10h07 alert was only 7 minutes old, and that's more recent then 10 minutes required by silences.expired=10m

Thanks for your answers.
Let me give you the real use cases

Question/bug 1

In the Production environment, we are not watching Karma all the time. We have other alerting systems. But Karma is the best tool to have an overview of all the alerts.

In this context, we would not set silences.expired to 10 minutes because we would miss that label nearly all the time. Setting 24h or even 72h (for week-ends) is more relevant.

Day 1...
18h00 : an alert fires
18h20 : I set a silence of 1 hour (and I try to fix the problem)
19h00 : the alert still fires and I decided that I could go home, the problem can be fixed tomorrow. I forgot to add a new silence for the night.
19h20 : the alert comes visible again (the silence expired)

For what I understand, the label "expired" will show only at 18h20 the day after (day 2).

In that case, that label is really needed at 7 am when colleagues come to work and will see that alert.

Question/bug 2

Back to the previous example (theoric example) : if you decide to not show the label at 10h10, for what reason would you show it at 10h12 ?

Transposition in the real-case example :
At 10am the day after, I see my alert still fires and I set a new silence for 12h (will expire at 10pm)
At 7am day 3, colleagues will see that alert again, but with the labels of the 2 silences. Why was the first label hidden at day 2 and why is it showing at day 3 ?

Hello,

Any update on this ?

Hello,

I was thinking... from Changelog v0.100 :

silences:expired option no longer takes alerts age into account.

Does that mean this issue has become N/A ?

I have not had time to test yet.

The issue became N/A since a while, probably since v0.100.
It can be closed.