Sizing Oracle Coherence

Rule-of-thumb: each 1 GB JVM can store 350 MB of actual object data

Personal Estimates: 80% of RAM can be used to store Heap (allocated to JVM); assuming no other softwares are running on the machine and make sure there is no active swapping.

Observation:
- In order to make sure that you don't loose GRID data(machine/node-safe), create a minimum cluster of 4 nodes on atleast 2 different machines.
- Best performant with multiple JVMs with memory = Xms = Xmx = 1GB

Examples:

If you would like to store 5GB of data on Coherence Grid, how much server memory and JVM required?

Step 1: 5GB object data would require 5/.35 = 14.28 ~ 15 JVMs with 1 GB memory allocated.
Step 2: It would be ideal to 15 JVMs on 5 machines and each machine running 3 Coherence JVMs
Step 3: Each machine should have RAM = 3/.8 = 3.75 GB (20% used by O/S)

So you would require 5 machines of 4GB to hold 5 GB actual object data. This estimate is on the higher side and can hold much more object data.