Shawn, I'm not running any parallel tests on any single node. Each node is configured with IE or Safari (the default version that ships with the OS we're testing: XP, Win7, Win8, Win8.1, OSX 10.8, OSX 10.9, latest version of Firefox, and latest version of Chrome. The max browsers per node is 1. The VMs are running on ESX server for windows, and on VMWare fusion on Mac (using a mac pro to host this since the VM requires an intel mac cpu). I believe all my VMs are running VMs configured with 1 core 2GHz, 2GB ram.
Krishnan, I still have to get around to looking into that self healing grid idea. I skimmed it when you answered another question of mine about implementing a drain functionality for seamless upgrades. I wasn't able to quickly incorporate that since I run in a python shop and using python for almost everything.
Yeah, I have a combination of different issues. The java memory leaks is one. Another is sometimes a browser would hang, and subsequent tests would fail if they ran on that node. On Safari VMs, I have tons open console windows, for some reason the Selenium Nodes on macs don't clean the console windows they spawn.