Why do we need to disable IM and Presence HA during IMP upgrading

[BenBen]

Hi,

I know upgrading and migration guide requires the disabling of IM and Presence HA before the upgrading of IMP. The disabling of the HA could introduce long period of interruptions for IM&Presence.

I am wondering why this is a necessity?

What happens if we don't disable the IM and Presence HA?

Thanks.

Ben

[Jonas Fraga]

Hello @BenBen 

I believe the biggest issue on keep HA available are the time off from half of your users during fallback process which can be made several times during restart services. This will impact the user experience which will feel like "unstable" software that keeps put them offline and online.

When you disable HA, all of your users can be moved to specific node which will reduce the downtime.

But it just my thoughts and maybe someone more "internal" on Cisco could explain better.