Generating unique key

[arypurnomoz]

How do we generate unique key for the record? Cassandra has their timeuuid generator, how about aerospike?

[chris]

Most programming languages have a UUID library. You can generate a UUID and use the raw bytes of the UUID as the value of a key.

• Java – UUID (Java Platform SE 7 )
• Python – 20.15. uuid — UUID objects according to RFC 4122 — Python 2.7.18 documentation
• Node.Js – GitHub - broofa/node-uuid: This code is now maintained at https://github.com/uuidjs/uuid
• C# – Guid.NewGuid Method (System) | Microsoft Docs
• Go – http://godoc.org/code.google.com/p/go-uuid/uuid
• Ruby – uuid | RubyGems.org | your community gem host
• C – uuid_generate(3): create new unique UUID value - Linux man page

[rbotzer]

And PHP - PHP: uniqid - Manual

[arypurnomoz]

@chris

UUID (Java Platform SE 7 )

Most programming languages uses type 4 UUID. Even it’s almost impossible that collision ever happen, if thinking about scaling, people will prefer something like type 1 UUID that is not randomly generated.

[holmes]

@chris , @rbotzer - What if we have to generate UID in a distributed system ?

Java UUID won’t ensure a unique key in that case.

[rbotzer]

You can use elements that add enough random noise to get around the timestamp collision problem.

For example in PHP you can use a function such as this:

function gen_id() {
  return uniqid(getmypid().getmyinode(), true);
}

Between the process ID, the inode of the file, and the microtime we get back a good unique ID, even for a distributed system, that runs around 1.4μs on my machine.

There should be elements such as those (MAC address of a card, process ID, etc) that work for your case.