title: Any algorithm/logic to generate 6 digit alphanumeric unique identifier in a multi process setup
body: <p>I have a use case where I need to generate 6 digit alphanumeric unique identifier. Have come across many solution but all seems to be fail in a multi processor environment and also might generate same unique identifier at some point of time.</p>
  
  <p>Is there any solution/algorithm to generate 6 digit alphanumeric unique identifiers at run time in a multi processor environment and should generate unique identifier always.</p>