Public address of unit changes take a while to update

[Haw Loeung]

Hi,

For units deployed in public clouds (AWS, Azure, etc.), the public address assigned is only for the duration that the unit is up and running. People often stop instances and start them back up, for example to address planned maintenance work by AWS or to resize to different flavors. Unfortunately, that then assigns new or different public addresses to these units which juju take ~10 mins or so to notice.

Any chance this could be noticed quicker? unit down + lost agent, then back up could perhaps inform the controller of the unit's new public address.

Or failing that, some command to force manual refresh of the cached public address?

This is two AWS environments running Juju 2.6.10.

To reproduce, spin up an instance or two. Login to the public cloud dashboard/portal, stop instance, wait, start. Instance should boot with different/new IPs. 'juju status' should show the old still until about ~10mins.

[Achilleas Anagnostopoulos (achilleasa)]

Issue affects both 2.6.x and 2.7-rcX. Working on a potential fix.

[Achilleas Anagnostopoulos (achilleasa)]

PR https://github.com/juju/juju/pull/10902 contains a fix scheduled to be released with 2.7.1

As there are no planned future releases for 2.6, I am flagging this as wont-fix for that track. However, the above PR can be easily back-ported if we need to.

[Haw Loeung (hloeung)]

Any chance of backporting to 2.6? It will be a while before we iron out bugs with 2.7 and roll it out across the board.

[John A Meinel (jameinel)]

It would be good to better understand how much of an impact there is for
you. This bug has been present in juju (pretty much forever), it isn't a
regression in 2.6. And we currently aren't planning any more 2.6 releases.
The particular patch *could* be backported, but it isn't trivial (involves
database changes), so itself comes with a small amount of risk.
If you feel very strongly, you can escalate with Tim to get a 2.6 out.

On Thu, Nov 28, 2019 at 12:50 PM Haw Loeung <email address hidden>
wrote:

> Any chance of backporting to 2.6? It will be a while before we iron out
> bugs with 2.7 and roll it out across the board.
>
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[Richard Harding (rharding)]

Just to agree with John that we did discuss if a backport was feasible but due to the scope of the change and that it's not that doesn't update, but the timeliness, it seemed not to be worth the risk/cost of a new 2.6 release with this in it.

If the impact is larger than we're understanding please do let us know so we can adjust our thinking but we do not currently expect to backport it.