Snowid is a service which generates unique sortable time-based 64 bit long identifiers.

[ 00000000000000000000000000000000000000000    0    0000000000 000000000000 ]
  |--------------(1)----------------------| |-(2)-| |---(3)--| |---(4)----|

1. 41 bits for Unix Timestamp with milliseconds
2. Reserved bit
3. 10 bits for Machine ID
4. 12 bits for incrementing number

The format is based on idea that each service in the cluster has its unique machine ID. It makes some points for running service. For example, if you run snowid in Kubernetes cluster, you should use StatefulSet instead of a regular Deployment.

The service also supports custom epoch to use it in the timer. Be careful with changing epoch setting for the existing services as it may bring collisions. usually, you don't need to change epoch during the lifetime.

1. Clone the repository
2. Run docker build . -t snowid:latest

go get github.com/azzz/snowid/cmd/snowid

The service is configured by setting environment variables.

LOG_LEVEL=info LISTEN=":8080" EPOCH="20210413001805" MACHINE_ID=333 snowid`

The service can be called by HTTP

description: Return an ID in both numeric and string formats. The string format might be useful if the language does not support 64 bit numbers. For example, JavaScript expects the numbers are 52 bits long.

content-type: application/json

Example:

{"numeric":41859390008987648,"string":"41859390008987648"}

> curl -i http://localhost:8080/id64
HTTP/1.1 200 OK
Date: Wed, 09 Jun 2021 18:25:13 GMT
Content-Length: 58
Content-Type: text/plain; charset=utf-8

{"numeric":41859390008987648,"string":"41859390008987648"}