esnowflake

Twitter's Snowflake UUID generator in Erlang


Keywords
erlang, otp, snowflake, uuid-generator
License
MIT

Documentation

Build Status

esnowflake

esnowflake is Erlang/OTP application to generate uniq ID.
Original design: Twitter IDs (snowflake).
Documentation

Usage

> application:start(esnowflake).
ok

> Id = esnowflake:generate_id().
896221795344384

> esnowflake:generate_ids(2).
[896498611015681,896498611015680]

> esnowflake:to_unixtime(Id).
1509193995927

> esnowflake:stats().
[{version, undefined},
 {worker_num,10},
 {worker_ids,[0,1,2,3,4,5,6,7,8,9]}]

1> {Start, End} = {os:system_time(seconds)-3600*24, os:system_time(seconds)}.
{1528603140,1528689540}
2> esnowflake:range_ids(Start,End, seconds).
[82304072417280000,82666460287074303]

Config

worker id

application environment variable

This must be specified as not to duplicate worker ids if you use multi nodes.

params default explain
worker_num 2 number of generate id workers
worker_min_max_id [0, 1] worker ids
redis - eredis config for assigning worker ids automatically
twepoch 1508980320000 start unix time to number id (default: 2017-10-26 01:12:00 (UTC))
  • redis config
params default
host localhost
port 6379
database 0
password (empty)
reconnect_sleep please check eredis:start_link/1
connect_timeout please check eredis:start_link/1
  • app.conf
[
 {esnowflake, [
               {worker_min_max_id, [0, 1]}
              ]}
].
[
 {esnowflake, [
               {redis, [{host, "localhost"}, {port, 26379}]},
               {worker_num, 2}
              ]}
].

Bench

----------------------------------------------------
2017-10-29 16:03:27.671
b_generate_id	100000	4564.13864 ns/op


----------------------------------------------------
2017-10-29 16:03:28.703
b_generate_id	232502 op/sec

%%% esnowflake_SUITE ==> bench.b_generate_id: OK

----------------------------------------------------
2017-10-29 16:03:29.700
b_generate_ids_100	10000	96834.8342 ns/op


----------------------------------------------------
2017-10-29 16:03:30.702
b_generate_ids_100	686 op/sec

%%% esnowflake_SUITE ==> bench.b_generate_ids: OK