Pause Button

[davkal]

• pauses topology and details panel updates
• buffers requests
• un-pause plays back the buffered requests
• automatically un-pauses when topology is changed, or other node is
  clicked (then discards buffer)

Fixes #1025

[peterbourgon]

If state == paused, button should be play triangle, right?

[errordeveloper]

This is really great!! The only thing I'm not too sure about is resume-on-click... When posting #1025, the use-case I had in mind was about exploring details of several nodes without having them move around, and potentially observe state of ephemeral nodes, as those naturally attract my attention.

[davkal]

If state == paused, button should be play triangle, right?

I prefer active/inactive pause. In the active state (paused) it blinks. This has the benefit of drawing attention to it in case the user wonders why nothing is updating. A blinking play button in a paused state would be misleading.

[2opremio]

Awesome!

I however think we should make the Pause state more predominant, otherwise:

1. User clicks pause (intentionally or by error)
2. User forgets about it
3. User sees that the UI is frozen and gets frustrated, blaming the software.
4. User reports bug (or even worse, user does a permanent stop :) )

[davkal]

the use-case I had in mind was about exploring details of several nodes without having them move around

I see, essentially pausing the topology, but keeping the freedom to explore nodes. Is that more desirable than the current implementation (freezing topology and details to show them to someone)?

and potentially observe state of ephemeral nodes, as those naturally attract my attention.

This is inherently impossible/difficult to manage in the UI because the nodes may be gone by the time you explore them at which point in time a request for details would come back empty.

[davkal]

I however think we should make the Pause state more predominant, otherwise:

User clicks pause (intentionally or by error)
User forgets about it
User sees that the UI is frozen and gets frustrated, blaming the software.

The safeguards here are:

• blinking pause button with incrementing update count
• click on a topology or node un-pauses

We could add more: (1) click on the background un-pauses, (2) show a confirmation dialog.

Could you give this a try @2opremio and see if you get stuck in a paused mode?

User reports bug (or even worse, user does a permanent stop :) )

We certainly dont want to undermine the utility of the product as a whole. If this button is too dangerous, we should simply close this PR.

[davkal]

Branch pause-topology-only keeps the topology fixed, but allows clicking/updating nodes.

[pidster]

This is inherently impossible/difficult to manage in the UI because the nodes may be gone by the time you explore them at which point in time a request for details would come back empty.

True until a timestamp parameter is supported & queries can be made against a history of reports...

[foot]

I really like the idea of being able to completely pause and inspect the system. Though due to current limitations this would be a tricky do.

• Grab all topologies data for every topo.
• Do a details call for every node in every topo.
• Store all this info.

Maybe for the next one.

Small things:

• Maybe include the label in the button here.
  
  • perhaps swapping "paused" for "resume" onMouseOver? Or just the tooltip.
• Set cursor: pointer; on all the buttons down here.
• If you have a details panel open and hit pause, the buffered chart animation keeps moving.
• The "indirect" (changin topo/clicking node) unpausing transition is a bit subtle, I didn't realise that I had unpaused the system by performing those actions.
  • Perhaps leave the "resuming" there for 3-4s, maybe w/ a darker bg/border that fades out.
  • orr set content of new topo/details panel to be a big fat play button.

[foot]

Being able to click around is quite nice!

Pros:

• Solves a known use case more clearly.

Cons:

• Some nodes will respond w/ a 404 i guess. (happens w/ both proposed solutions though).
• Confuses the meaning of paused a little as less stuff in the UI is paused.

Its easier to forget the topo is paused if you're off exploring details, I'd make the pause state a tiny bit more prominent, maybe bold + leave the border around the button + label when activated.

I'm +1 on pause-topology-only though.

[foot]

LGTM after TAL! Button looks slick.

Use case coverage:

• + Can pause and look over the topo and see how transient nodes are connected.
• - Probably can't see the details of these transient nodes as the BE won't know about them anymore after a second or two.

But I think this is a good start!