CloudBees and App Cells, Instances and Pools

Question

I am trying to understand the difference between:

• An app-cell
• An app instance; and
• An app pool

For instance, how do I know when it is appropriate to add more app-cells for my app? Or to add more instances? Or to configure a certain subset of them into a pool? Thanks in advance!

Selfmastery

Answer 1

Mostly an app-cell is a unit of measuring both memory and a "fair share" of both IO and CPU.

1 cell is 128meg-ish - and thus 8 cells would be 8 times that (including not just memory etc).

An app-instance is a JVM running on a server (so if you have 3 instances that is 3 JVMs if it is a java app) - but they are 3 instances of the same "size" of JVM - so a cell is really a measure of size.

Pools are unrelated and only relevant if you are going with dedicated plans and need to plan capacity (by default you can ignore that).

Plunkett

Thanks @Michael Neale (+1) - so quick question, if I have a 2 app-cell web app (WAR), and I have 3 instances of it running, do I actually have 6 app-cells running at the same time? Thanks again! – Selfmastery