ArcGIS Server multiple-machine deployment Experiences

[ScottCorwin]

Hi, looking for feed back on going from an singe ArcGIS GIS Server site to a multi-machine site.  Technically it's already a multi-machine site with ArcGIS Image Server on one machine and ArcGIS GIS Server on the other, both are federated.  We are running around 150-160 services utilizing over 80% of our memory sometimes spiking into the 90's when someone starts an edit session in portal.  So one potential solution would be to add another ArcGIS GIS Server.  One specific question I do have, is how does this get managed? Do I as the admin get to decide GP services on machine A and pooled instances on machine B, or does some aspect of the Server software manage this without user input?

[jcarlson]

We've got close to the same number of services, but our memory hangs out around 50% and rarely spikes. You may not actually need another server. Make sure your published services are taking advantage of the shared instance pool. I would recommend avoiding dedicated services entirely unless it's for a mission-critical service. I suppose that could be the case for all your services.

[ScottCorwin]

Josh, thank you for the reference, it's always helpful to see how other sites run, how much memory does your server have?  We are heavy on dedicated not so much in shared. 

[jcarlson]

I had to double check this, but it's true: we're doing it on 16 GB RAM! I think 32 would be nice, but it hasn't been necessary for day-to-day operations. But we do nearly everything on shared instances, and the two dedicated services have a minimum instance setting of zero, so that those processes exit entirely when not in use.

EDIT: I also double-checked our service count, and we have over 250 services running on shared instances. So, I think it's working out pretty well.

[ScottCorwin]

That's impressive! Is startup delay even perceptible on the dedicated services?   

[jcarlson]

No, not really. We only have two dedicated services, both are parcel fabrics, and both are only used internally. Since we work with the fabrics in Pro, the service is usually on and available before Pro has finished loading the project.

[JimCarmichael1]

When you say you have ArcGIS Image Server on one machine and it’s federated, is it a separate GIS server site or did you end up joining it to your existing ArcGIS server site. We are thinking of deploying an Image Server primarily for image hosting, but I’m confused during setup if I need to join it to the existing GIS Server site or if it’s possible to just create a new site, federate it to our portal, publish image services to it, and then use a web adaptor to access the REST of that Image Server site?

[ScottCorwin]

Our image server is it's own server site.  So you are on target for the remainder of your idea, stand up the image server configure the webadaptor and then federate it to portal.   

[MichaelJenkins]

You would  not want to join it to your existing ArcGIS Server site for the reasons discussed earlier in this thread -- if joined then both machines would split all of the work.  Keep them separated.