ruler: Add flag to configure the queue for pending Alertmanager notif…

[roth-wine]

• [x] I added CHANGELOG entry for this change.
• [ ] Change is not relevant to the end user.

Changes

Add flag to configure the queue for pending Alertmanager notifications In the prometheus package we are already able to configure the capacity size. The fixed value could lead to issues sending alerts when evaluating a huge amount of alerts in one ruler instance.

[roth-wine]

Failing test seems unrelated to my changes and might be flacky.

[roth-wine]

Unfortunately, I don't know what a “good” value is or should be. Both the implementation in Thanos and the implementation in Prometheus don't mention anything about this. That's why I would just leave the default and make it configurable as needed.

We can also set the flag to hidden if you prefer.

[GiedriusS]

I think let's then make it hidden :+1:

[roth-wine]

I have made the flag hidden :smile:

[roth-wine]

Failing test seems again unrelated to my changes and might be flacky.

[roth-wine]

@GiedriusS can this get merged?

[roth-wine]

@GiedriusS i have rebased the branch to get this thing merged. Failing tests are flacky and not related to my changes.

[roth-wine]

@GiedriusS any updates on getting this merged?