Distributed sequence number generation?

Question

I\'ve generally implemented sequence number generation using database sequences in the past.

e.g. Using Postgres SERIAL type http://www.neilconway.o

Answer 1

There are a few strategies; but none that i know can be really distributed and give a real sequence.

1. have a central number generator. it doesn't have to be a big database. memcached has a fast atomic counter, in the vast majority of cases it's fast enough for your entire cluster.
2. separate an integer range for each node (like Steven Schlanskter's answer)
3. use random numbers or UUIDs
4. use some piece of data, together with the node's ID, and hash it all (or hmac it)

personally, i'd lean to UUIDs, or memcached if i want to have a mostly-contiguous space.