Under Construction During Upgrade

[RogerDunnGIS]

Later this month, we'll be upgrading to Enterprise 11.3.  During the upgrade, I'd like site visitors to see a nice "Under Construction" page with some basic information, like when the upgrade will be complete.  However, I don't want to adversely affect the installation that is occurring.  I'm just looking for a clean solution than error messages if and when browsers visit our ArcGIS Server and Portal URLs.  We are using IIS.  Is there a method to do this?

[jcarlson]

I'd just create a custom 404 page.

https://www.ntweekly.com/2017/07/14/how-to-set-a-custom-404-error-page-on-iis-10/

Here's ours: https://maps.co.kendall.il.us/arcgis

You could easily edit the custom page to say some kind of "under construction" message, then flip it back to a standard 404 page later. Given that uninstalling your Web Adaptor is part of the upgrade process, your portal will be unavailable for some of the process, and a 404 will be the default response to a connection attempt in that window.

A more specific approach would be to use IIS URL rewrite rules to point any /server or /portal requests to a custom HTML page about the upgrade. Personally, I see that as more work than it's worth. The portal itself usually upgrades pretty quickly, and you can get it back online and use a banner notice about the maintenance while your server upgrade is in progress.

[RyanUthoff]

As long as you're running a version of ArcGIS Enterprise that supports it, at minimum, you can put notification banners in Portal that will notify users of upcoming maintenance.

Alternatively, depending on your environment, you might be able to get creative with your public IP routing and hosts file. You can spin up another server that hosts your basic website. Then move your existing public IP to the new server so anyone trying to access Portal will get routed to the new server with your basic website. Of course, you might need to edit the hosts file on your production machines so any traffic coming from that machine doesn't get inadvertently routed to your new machine and mess up the upgrade.

That might be an overly convoluted way of doing it. Other might have much simpler ideas.

[Scott_Tansley]

IIS supports this natively.  You can use this blog from Esri Canada that explains the detail of it:

https://resources.esri.ca/getting-technical/effectively-communicating-arcgis-enterprise-downtime

Basically put one of the files into each Web Adaptor folder and it blocks that component.  If I need to open it up temporarily for testing,then i change the file name to app_offline!.htm and when i want to lock it out then I change it back to app_offline.htm.  You don't need to do anything in IIS other than copy the file in and then delete it after.