Hybris

For Setting Java_home:

$ Path for Java Location /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home export JAVA_HOME=

For changing host entries:

https://www.imore.com/how-edit-your-macs-hosts-file-and-why-you-would-want

For too many files open in the system :

https://superuser.com/questions/433746/is-there-a-fix-for-the-too-many-open-files-in-system-error-on-os-x-10-7-1 https://stackoverflow.com/questions/10095796/os-x-terminal-ssh-and-too-many-open-files

ulimit -a

ulimit -n 1000000

You can check these with:

sysctl kern.maxfiles
sysctl kern.maxfilesperproc
You can increase the limits (at your own risk) with:

sysctl -w kern.maxfiles=20480 (or whatever number you choose)
sysctl -w kern.maxfilesperproc=18000 (or whatever number you choose)
To make the change permanent, use sudo to put your settings in /etc/sysctl.conf (which you may have to create), like this:

kern.maxfiles=20480
kern.maxfilesperproc=18000