How to setup SSH private and public keys

• 1)
  % ssh-keygen -t rsa -b 4096 Generating public/private rsa key pair.
  Enter file in which to save the key (~/.ssh/id_dsa): (just press Enter) 
  Enter passphrase (empty for no passphrase): (enter a passphrase and then press Enter or if you don't want want one just press Enter) 
  Enter same passphrase again: (repeat last action) 
  Your identification has been saved in ~/.ssh/id_rsa
  Your public key has been saved in ~/.ssh/id_rsa.pub
  The key fingerprint is:
  A long string appears here
  %
• 2)
  Paste the content of the  ~/.ssh/id_dsa.pub file that just got generated on your local host into the file ~/.ssh/authorized_keys on the remote host and save.
• 3)
  Set proper permissions on your local host keys and .ssh directory:
  chmod 700 ~/.ssh
  chmod 644 ~/.ssh/id_rsa.pub
  chmod 600 ~/.ssh/id_rsa
  set proper permissions on your remote host authorized_keys and .ssh directory
  chmod 700 ~/.ssh
  chmod 644 ~/.ssh/authorized_keys
  

How to take a Java thread dump from a shell/bash script

We already know how to get a Java thread dump manually. But what if we want to take a Java thread dump from a script to help us automate things.

To do this we need to come up with a ps and grep combination that will only return one result. so grep as many times as neccessary and/or use keywords that are only found in your process name so you only get one result.

Remember to add [] somewhere in your first grep so grep doesn't matches itself.

output=$(ps -ef | grep m[y]ProcesseName )

Then all you need to do is sending the QUIT signal to $2 which stores the PID of your process.

kill -QUIT $2

So just add the above two lines to your script after modifying the first line to fit your needs and you should be good to go.