The NPM SLX license is "unlimited" because you don't have to purchase this licensing individually for each APE you deploy. For instance, your one NPM SLX license should work for 1 NPM Server + 9 APE's, without you having to buy (and annually renew) 10 SLX licenses.
The "unlimited" is not talking about the performance of the server, it's talking about the overall total for which can be potentially supported elements within the same Orion architecture.
At least, that is how I understand it. If there's someone out there with a large deployment who could confirm this, that'd be neat.
I'm opening a support case on this, because it was not my understanding at all. If I don't have to purchase licensing for an APE, that's a relief, and will be news to my salesperson.
However, I don't think this is the correct answer, as the price list you linked to includes an entry for:
SolarWinds Additional Polling Engine for SolarWinds Unlimited Licenses (Standard Polling Throughput) - License with 1st Year Maintenance
Additionally, I don't have a link to download the APE software.
I'll update this thread if I hear officially.
The licenses for elements don't have to be purchased again with an SLX license.
You WILL have to purchase a license to deploy an APE.
Hopefully this helps clarify - installing an additional APE isn't free, you just don't have to pay for an additional SLX license with it.
If I have an SLX license and a primary poller only, I pay for the SLX license and I'm done.
If I want to expand to include an additional APE, I pay only for the APE's licensing, and I don't have to buy an additional SLX license specifically for the APE.
"Unlimited" means if I want to install 9 APE's with a primary poller and have 100,000 polled elements, I can do that on the one SLX license, but I will also have to purchase the 9 APE software licenses in order to support the total.
Then I stand by my original statement that the limit is an artificial one imposed by software, and that the "Unlimited" in "Network Performance Monitor - Unlimited Elements" is patently false.
I see your logic if you separate NPM from the poller, but they aren't separate. They come bundled together under one sku that bills itself as unlimited.
This is frustrating and misleading.
Just as dhanson mentioned unlimited license means you donot need to buy anymore NPM licenses no matter how many additional pollers you add. But the engine does have a limitaion on how much information it can process at the default polling level. You could have more than 12k elements on a single pollar and the system will run as long as the resources are there but after it goes over 100% of its polling threashhold it will start automaticly raising the polling times. To make sure you stay at the default polling times you will need to add an additional poller at around 12k elements.
Others have commented, but missed the point of the question -- like the original questioner, on my additional polling engines (and main server) I cannot see what system resources are constrained in such a way that I need to install another server to support more load (the boxes have spare CPU, RAM, IO bandwidth) other than due to a software limit imposed by something inside NPM
Each year we renew the maintenance on each product plus the four additional polling engines (and FOE)
I agree with @fdamstra buying an unlimited license for SAM/NPM maked me think that i'm set as far as licensing needs go. Needing to buy additional pollers for Orion which is an after thought especially when you dont know how the product works until after you've bought it really sucks.