Globally unique key generation strategy - implementation principle of the sender

background

• Our system is distributed , A globally unique quantity is required to identify a field
• Because of the complexity of the system , We need to understand these key Operation and maintenance

The transmitter

The business process

• Call interface - nextId
• server Go to redis-cluster Get a self increment , And back to
• Obtained by microservice server The value returned , And write it to the database

Basic model

Realization principle

redis Single thread model

Source code

java

com.youzan.paas.march.sdk.BasicClient#next
com.youzan.paas.march.sdk.JedisBackend#incr
redis.clients.jedis.JedisCluster#incr
redis.clients.jedis.Client#incr
redis.clients.jedis.BinaryClient#incr
this.sendCommand(Command.INCR, new byte[][]{
    key})
connect();
redis.clients.jedis.Protocol#sendCommand(RedisOutputStream,redis.clients.jedis.Protocol.Command, byte[]...)
  

c

c_string.incrDecrCommand
getLongLongFromObjectOrReply // have a look key Is there any 
value += incr;  inct =1,  take value+1
dbOverwrite,// Overwrite the original value 

Other distributed id

The algorithm name	Belongs to	Reference material
snowflake	twitter	https://github.com/beyondfengyu/SnowFlake
Leaf	Meituan	https://github.com/Meituan-Dianping/Leaf
tinyid	sound of dripping water	https://github.com/didi/tinyid
uid-generator	Baidu	https://github.com/baidu/uid-generator
…		…

summary

• This paper introduces the background of the annunciator , And the problems to be solved
• Basic model CS
• Realization principle
• Other Internet companies are distributed id Generation strategy for