Unique ID generator based on Twitter Snowflake, but in PHP with a simple ZeroMQ interface (rather than Thrift).
This is a rewrite of dvomedia/cruftflake. It organizes the code in modules and adds several interfaces, allowing easier extension of other server and configuration mechanisms.
The implementation copies Twitter - generating 64 bit IDs.
- time - 41 bits
- configured machine ID - 10 bits
- sequence number - 12 bits
Has a custom epoch that means it can generate IDs until 2081-09-06 (not the same epoch as Snowflake).
We use ZooKeeper to store which machine IDs are in use. When a new node starts up for the first time it must be able to contact the ZooKeeper cluster and create a new node. It will look at all the existing nodes and then (if it can't find its own Mac Address) attempt to claim a free one.
I was using Ephemeral nodes for this - similar(ish) to a lock pattern but this had the issue that the node needed to remain connected to ZK throughout its lifetime -- this way it doesn't.
The downside is that potentially the 1024 possible machine IDs will "fill up" and need to be manually pruned.
Installation via composer:
{
"require": {
"gendoria/cruftflake": "*"
}
}
There are several example scripts provided for playing about with. Both require previous composer update.
-
The generator (the server)
./examples/server.php
-
A client, that will generate N IDs and dump to STDOUT
./examples/client.php -n 100
-
A client, that will ask server for generator status
./examples/status.php
For client examples to work, server example has to be be running.
- ZeroMQ
- ZooKeeper (if you want to use ZooKeeper centralized configuration)
- Doctrine DBAL >= 2.3.0 (if you want Doctrine DBAL centralized configuration)
Composer requires php-zmq module installed.