Unique ID generation scheme in distributed systems.Snowflake & Sonyflake
Feature
Unique ID generator
Green pluggable, without external storage like Redis or MySQL
Suitable for distributed systems
Snowflake
1-bit Reserve (always 0)
41-bits Time (millisecond precision, a custom epoch gives us 69 years)
10-bits Configured machine id (gives us up to 1024 machines)
12-bits Sequence number (rolls over every 4096 per machine)
minimum 2m ids per second per process
response rate 2ms (plus network latency)
Sonyflake
1-bit Reserve (always 0)
39-bits Time (10-milliseconds precision, a custom epoch gives us 174 years)
8-bits Sequence number (rolls over every 256 per machine)
16-bits Configured machine id (gives us up to 65536 machines)
minimum 10k ids per second per process
response rate 2ms (plus network latency)
Limition
生成规则中含有时间位，表明在同一个节点的同一个时间单元内，仅通过自增ID来约束，如果节点在时间单元内重启，有可能导致在该节点上出现重复ID。（延迟重启时间间隔, Snowflake > 1ms, Sonyflake > 10ms）
Solution
https://github.com/bwmarrin/snowflake
https://github.com/sony/sonyflake