[Fleet] Ugrade Agent feature can hang the UI for a minute while processing

[EricDavisX]

Kibana version:
commit: 7.11 snapshot cloud install of whole stack, with 7.10 BC1 Agent
edavis-mbp:kibana_elastic edavis$ git show -s 29426f5
Date: Mon Oct 12 12:35:00 2020 +0200

Agent hash 116336aa, the BC1 build from : elastic-agent-7.10.0-linux-x86_64.tar.gz
from the elastic /dev/issues/1496 release repo.
7.10.0-116336aa
https://staging.elastic.co/7.10.0-116336aa/downloads/beats/elastic-agent/elastic-agent-7.10.0-linux-x86_64.tar.gz

Browser version:
Chrome on macOS

Describe the bug:
The UI is unresponsive to clicks for about 1 minute, after I execute the API call to upgrade the Agent from 7.10 to 7.11 snapshot.

Steps to reproduce:
see details in main 'upgrade' Agent e2e-testing issue, here:
elastic/e2e-testing#341 (comment)

Expected behavior:
UI is responsive and doesn't "hang"

Screenshots (if relevant):
here is a zipped movie:
https://drive.google.com/file/d/1FbSF7FTH61S97IShUkF38zTi6zHx_F-1/view?usp=sharing
there is a horizontal bar going across the UI every second or so showing it is still thinking...

Errors in browser console (if relevant):
none

Provide logs and/or server output (if relevant):
n/a

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[EricDavisX]

In my scenario the API call seems to work, but it hits a bug on the Agent side regarding .asc / gpg file checks and eventually fails. I don't know if this 'hang' happens when the feature succeeds, I have not yet successfully tested (still working on it).

[jfsiii]

We shouldn't cause this poor experience even if we can't find/open a file. There's almost certainly something we can do to avoid the hanging.

[ph]

@EricDavisX Still a valid issue?

[EricDavisX]

I don't think we've checked in anything that would change this. It should only be seen with incorrect API usage, to confirm.

[jen-huang]

As Upgrade Agents is an experimental feature (even after Fleet itself goes GA, I'm de-prioritizing this).

[jlind23]

Closing this for now until further report