Feedback on the (perhaps not so) new Alertmanager silence UI

[Saj Goonatilleke]

Hello,

We recently updated from Alertmanager 0.17.0 to 0.23.0. I found the new
silence matcher UI to be a little confusing and difficult to wield. This
message does amount to subjective feelpinion, so I opted to send to the
list instead of a bug report.

This feedback pertains to the 'Edit Silence' UI; specifically this bit:

> *Matchers* Alerts affected by this silence

Previously, each matcher was listed on a different line in a tabulated
fashion. Now, each matcher behaves like a word in a sentence, with the
sentence wrapped over multiple lines at unpredictable line break points.
I would like to make a case for the old layout. Here's a fairly
common workflow for me:

1. Something goes boom. I decide to silence.
2. Navigate to the AM index.
3. Click the 'Silence' button alongside a firing alert.
4. Hit the X button alongside many unnecessarily specific matchers.
5. Preview and create the silence.

Depending on the nature of the thing that went boom, I can expect to see
related alerts with some overlapping label values (like a job name) but
other label values (like container or machine identifiers) can be
expected to differ. This stuff is just noise in the silence. Step (4)
gets rid of that noise.

With the old layout, the removal of a matcher did not change the
horizontal positions of other matchers. Some would simply move up by
one vertical line. This tabular layout was easy to eyeball and read.
Like deleting a row from a spreadsheet. The buttons were vertically
aligned, too, so I could easily roll my cursor down the window. On the
new layout, many matchers reshuffle themselves to different horizontal
and vertical positions. I'm not entirely sure why, but I find this much
harder to read. Maybe something to do with spatial memory.

My other feedback mostly flows from the same UI change.

Suppose you would like to edit one of the matchers (instead of simply
removing it). Perhaps a string comparison needs to be changed to a
looser regexp match. IIRC, the old layout simply presented a set of
textbox inputs that could be directly manipulated. That was nice. And
fast. In the new layout, the textbox inputs were removed and replaced
with a multi-step click-to-edit flow. Clicking on a matcher will
shuffle it to a completely different horizontal and vertical position.
Only then does a textbox input present itself for typing.

Previously, it was satisfactory to frob the textbox input and hit the
Preview button to review the change. Now, one must hit the '+' button
after typing but before hitting the Preview button. The additional step
is a little tedious, but the edit flow is what I take most issue with:
if I do not intend to add a new matcher, it seems unnatural to click on
a button labelled with a plus symbol. (Upon first encountering the new
UI, it took me an embarrassingly long time to work out how to dispel the
'Please complete adding the matcher' error message.)

I do apologise if I come across as a bit of an ungrateful curmudgeon.
That was not my intent. Other recent-ish changes to the Prom UI were
very well received: the /targets UI is a personal favourite. But, in
this specific case, I do wonder whether simpler was perhaps better. :)

Thanks for your time and consideration.

[Brian Candler]

I can't answer for the alertmanager UI, but I do note that there are other UIs which can talk to it - in particular karma can do this, and the way it does it seems straightforward enough to me.