Was part way into 8.0 upgrades and made the switch to 8.1.
Ran into an issue where using admin-console on the root hub was causing all kinds of slowness and eventual unresponsiveness of the tomcat server for the service-host. This would also cause inf-manager gui to slow down when logged in against the primary hub. Some browser and log file debugging showed repeating requests that were failing and I think possibly beating up the hub or controller too.
I bumped up debug logging and opened a support case. Support was no help, but I eventually fixed the issue by reinstalling a bunch of service-host packages while service-host was disabled just in case a late exiting tomcat process was preventing a proper update via the installer.
admin_console
ids_services
uimserver_home
service_host
monitoring_services
discovery_server
This fixed the issue, but the console was still a little sluggish. Bumping the java heap options and disabling compression on the connector within service-host.cfg made is much faster.
Ironic bug. I also updated ppm to 3.03 which wasn't included in the updates but is available in the internet archive while trying to fix a bug. When trying to access ppm probe config via admin console, the browser spins while admin_console waits for ppm which loses it's mind trying to find ctd info for itself until it times out. This is not fixed in 3.03, but 3.03 will give you some updated config options for some probes.
Adminconsole is pretty horibly documented. Some details I've pieced together.
Problem: Adminconsole works on the LAN, but you get a "can't access server" error in the ump portlet externally. There really isn't an adminconsole portlet for ump. The portlet really just tries to find the service host and send you to adminconsole via a re-post of credentials to the service host in an iframe. This is great if you happen to be on the same LAN as the admin console when accessing UMP. It can probably be worked around by setting the /host/name parameter in service_host.cfg to a public DNS name and allowing access to the service host through the firewall. They also have a work around in a KB article suggesting you manually setup the iframed portlet.
https://na4.salesforce.com/articles/HowToProcedures/How-to-access-admin-console-from-public-IP-address-within-UMP
Documentation bug: PPM documentation is hard to come by. It's just one of those essential things that they think will just work. Anyway, for adminconsole to work, ppm must be deployed to every hub in the environment. This has trickled from the software requirements in older versions to the known issues in 8.0, and has been overlooked in 8.1. 8.1 suggests you deploy all components of service-host to all hubs in the environment which is obviously not what you want if you don't want promote every remote network to a management network.
Unknown bug: setting /loggers/org.apache.http = INFO shows a repeating error when you browse admin console indicating that somewhere in the code the admin-console is trying a get_probe REST callback that is not implimented in any of the components of service_host. I don't know what the impact is.
Jan 08 10:27:32:285 [attach_socket, service_host] getApps: detailLevel: 1
Jan 08 10:27:32:285 [attach_socket, service_host] callAppRest: adminconsole/callbacks/get_probe
Jan 08 10:27:32:288 [attach_socket, service_host] service_host app adminconsole doesn't implement callbacks/get_probe
Jan 08 10:27:32:288 [attach_socket, service_host] failed callbacks/get_probe error calling GET http://192.168.43.147:8080/adminconsole/callbacks/get_probe HTTP/1.1 code: 404
Jan 08 10:27:32:288 [attach_socket, service_host] callAppRest: ids_services/callbacks/get_probe
Jan 08 10:27:32:291 [attach_socket, service_host] callAppRest: monitoring_services/callbacks/get_probe
Jan 08 10:27:32:295 [attach_socket, service_host] callAppRest: ROOT/callbacks/get_probe
Jan 08 10:27:32:296 [attach_socket, service_host] service_host app ROOT doesn't implement callbacks/get_probe
Jan 08 10:27:32:296 [attach_socket, service_host] failed callbacks/get_probe error calling GET http://192.168.43.147:8080/ROOT/callbacks/get_probe HTTP/1.1 code: 404
Jan 08 10:27:32:296 [attach_socket, service_host] callAppRest: umpjslib/callbacks/get_probe
Jan 08 10:27:32:298 [attach_socket, service_host] service_host app umpjslib doesn't implement callbacks/get_probe
Jan 08 10:27:32:298 [attach_socket, service_host] failed callbacks/get_probe error calling GET http://192.168.43.147:8080/umpjslib/callbacks/get_probe HTTP/1.1 code: 404
Documentation bug: The 8.1 post install validation chart references several versions incorrectly. Specifically 8.1 installs versions newer than what they suggest it does.