Nine kinds of distributed primary key ID generation schemes of sub database and sub table are quite comprehensive

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"link","attrs":{"href":"https://mp.weixin.qq.com/s/AUvcsschhqrhKopM5-XeMA","title":""},"content":[{"type":"text","text":"《sharding-jdbc Sub database and sub table 4 Seed fragmentation strategy 》"}]},{"type":"text","text":" We introduced "},{"type":"codeinline","content":[{"type":"text","text":"sharding-jdbc"}]},{"type":"text","text":" 4 The usage scenarios of the fragmentation strategy , Can meet the basic fragmentation function development , Let's look at the sub database table , How to generate a globally unique primary key for a partitioned table "},{"type":"codeinline","content":[{"type":"text","text":"ID"}]},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" There are risks in introducing any technology , Database and table are no exception , Unless the library 、 The amount of table data continues to increase , To a certain extent , As a result, the existing high availability architecture has been unable to support , Otherwise, we do not recommend that we do the sub database table , Because after slicing the data , You'll find yourself on a path of stepping into a pit , And distributed primary keys "},{"type":"codeinline","content":[{"type":"text","text":"ID"}]},{"type":"text","text":" It's the first pit that we met ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" It is a difficult problem to generate a global unique primary key between different data nodes , A logic table "},{"type":"codeinline","content":[{"type":"text","text":"t_order"}]},{"type":"text","text":" Split into multiple real tables "},{"type":"codeinline","content":[{"type":"text","text":"t_order_n"}]},{"type":"text","text":", And then it's distributed to different libraries "},{"type":"codeinline","content":[{"type":"text","text":"db_0"}]},{"type":"text","text":"、"},{"type":"codeinline","content":[{"type":"text","text":"db_1"}]},{"type":"text","text":"... , Since the auto increment keys of the real tables cannot be perceived by each other, they will produce duplicate primary keys , At this time, the database itself adds its own primary key , It can't meet the requirement of global uniqueness of primary key in sub database and sub table ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"java"},"content":[{"type":"text","text":" db_0--\n |-- t_order_0\n |-- t_order_1\n |-- t_order_2\n db_1--\n |-- t_order_0\n |-- t_order_1\n |-- t_order_2"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Although we can be strictly bound , Each partition table automatically increases the primary key "},{"type":"codeinline","content":[{"type":"text","text":" Initial value "}]},{"type":"text","text":" and "},{"type":"codeinline","content":[{"type":"text","text":" step "}]},{"type":"text","text":" To solve the problem "},{"type":"codeinline","content":[{"type":"text","text":"ID"}]},{"type":"text","text":" Repetitive questions , But this will make the operation and maintenance cost increase sharply , And the scalability is very poor , Once you want to expand the number of split tables , The data in the original table changed a lot , So it's not very desirable ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"java"},"content":[{"type":"text","text":" step step = The number of separate sheets \n\n db_0--\n |-- t_order_0 ID: 0、6、12、18...\n |-- t_order_1 ID: 1、7、13、19...\n |-- t_order_2 ID: 2、8、14、20...\n db_1--\n |-- t_order_0 ID: 3、9、15、21...\n |-- t_order_1 ID: 4、10、16、22...\n |-- t_order_2 ID: 5、11、17、23..."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" There are many third-party solutions that can solve this problem perfectly , For example, based on "},{"type":"codeinline","content":[{"type":"text","text":"UUID"}]},{"type":"text","text":"、"},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":" Algorithm 、"},{"type":"codeinline","content":[{"type":"text","text":"segment"}]},{"type":"text","text":" Paragraph number , Generate non repeating keys using a specific algorithm , Or directly reference the primary key generation service , Like the US regiment （"},{"type":"codeinline","content":[{"type":"text","text":"Leaf"}]},{"type":"text","text":"） and sound of dripping water （"},{"type":"codeinline","content":[{"type":"text","text":"TinyId"}]},{"type":"text","text":"） etc. ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" and "},{"type":"codeinline","content":[{"type":"text","text":"sharding-jdbc"}]},{"type":"text","text":" Two distributed primary key generation schemes are built in ,"},{"type":"codeinline","content":[{"type":"text","text":"UUID"}]},{"type":"text","text":"、"},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":", Not only that, it also takes away the interface of the distributed primary key generator , In order to facilitate developers to implement a custom primary key generator , In the future, we will connect to the custom generator sound of dripping water （"},{"type":"codeinline","content":[{"type":"text","text":"TinyId"}]},{"type":"text","text":"） Primary key generation service for ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" As mentioned earlier in sharding-jdbc To automatically generate a primary key for a field ID, Only need "},{"type":"codeinline","content":[{"type":"text","text":"application.properties"}]},{"type":"text","text":" Do the following configuration in the file :"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"javascript"},"content":[{"type":"text","text":"# Primary key field \nspring.shardingsphere.sharding.tables.t_order.key-generator.column=order_id\n# Primary key ID Generation scheme \nspring.shardingsphere.sharding.tables.t_order.key-generator.type=UUID\n# Work the machine id\nspring.shardingsphere.sharding.tables.t_order.key-generator.props.worker.id=123"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"codeinline","content":[{"type":"text","text":"key-generator.column"}]},{"type":"text","text":" Represents the primary key field ,"},{"type":"codeinline","content":[{"type":"text","text":"key-generator.type"}]},{"type":"text","text":" Primary key ID Generation scheme （ Built in or custom ）,"},{"type":"codeinline","content":[{"type":"text","text":"key-generator.props.worker.id"}]},{"type":"text","text":" For the machine ID, Set the primary key generation scheme to "},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":" Time machine ID Will participate in bit operations ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"> In the use of sharding-jdbc Two things should be noticed when distributed primary key is distributed ："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" once "},{"type":"codeinline","content":[{"type":"text","text":"insert"}]},{"type":"text","text":" The primary key field in the entity object of the insert operation has been assigned , Then even if the primary key generation scheme is configured, it will fail , Last SQL The data executed will be based on the value assigned ."}]}]},{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Don't set auto increment attribute to primary key field , Otherwise, the primary key ID By default "},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":" How to generate . such as ： use "},{"type":"codeinline","content":[{"type":"text","text":"mybatis plus"}]},{"type":"text","text":" Of "},{"type":"codeinline","content":[{"type":"text","text":"@TableId"}]},{"type":"text","text":" Annotate fields "},{"type":"codeinline","content":[{"type":"text","text":"order_id"}]},{"type":"text","text":" Auto increment primary key is set , What kind of solution to configure at this time , Always follow the snowflake algorithm ."}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"horizontalrule"},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Let's analyze it from source sharding-jdbc Built in primary key generation scheme "},{"type":"codeinline","content":[{"type":"text","text":"UUID"}]},{"type":"text","text":"、"},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":" How did it happen ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"UUID"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" open "},{"type":"codeinline","content":[{"type":"text","text":"UUID"}]},{"type":"text","text":" The primary key of type generates the implementation class "},{"type":"codeinline","content":[{"type":"text","text":"UUIDShardingKeyGenerator"}]},{"type":"text","text":" Source code discovery for , Its generation rules are only "},{"type":"codeinline","content":[{"type":"text","text":"UUID.randomUUID()"}]},{"type":"text","text":" Such a line of code , forehead ~ There is a word in my heart "},{"type":"text","marks":[{"type":"strong"}],"text":" Oh my god "},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"UUID Although we can achieve global uniqueness , But it is still not recommended as a primary key , Because we do business in real life, whether it is "},{"type":"codeinline","content":[{"type":"text","text":"user_id"}]},{"type":"text","text":" still "},{"type":"codeinline","content":[{"type":"text","text":"order_id"}]},{"type":"text","text":" Primary keys are mostly integers , and UUID It's a 32 Bit string ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Its storage and query to "},{"type":"codeinline","content":[{"type":"text","text":"MySQL"}]},{"type":"text","text":" High performance consumption , and "},{"type":"codeinline","content":[{"type":"text","text":"MySQL"}]},{"type":"text","text":" Officials have also made clear their recommendations , The primary key should be as short as possible , As a database primary key UUID The disorder of the data also leads to frequent changes in data locations , Seriously affect performance ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"javascript"},"content":[{"type":"text","text":"public final class UUIDShardingKeyGenerator implements ShardingKeyGenerator {\n private Properties properties = new Properties();\n\n public UUIDShardingKeyGenerator() {\n }\n\n public String getType() {\n return \"UUID\";\n }\n\n public synchronized Comparable generateKey() {\n return UUID.randomUUID().toString().replaceAll(\"-\", \"\");\n }\n\n public Properties getProperties() {\n return this.properties;\n }\n\n public void setProperties(Properties properties) {\n this.properties = properties;\n }\n}\n"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":"（ Snowflake algorithm ） Is the default primary key generation scheme , Generate a 64bit Long integer （"},{"type":"codeinline","content":[{"type":"text","text":"Long"}]},{"type":"text","text":"） data ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"codeinline","content":[{"type":"text","text":"sharding-jdbc"}]},{"type":"text","text":" The primary key generated by snowflake algorithm is mainly composed of 4 Part of it is made up of ,"},{"type":"codeinline","content":[{"type":"text","text":"1bit"}]},{"type":"text","text":" Sign bit 、"},{"type":"codeinline","content":[{"type":"text","text":"41bit"}]},{"type":"text","text":" Time stamp bit 、"},{"type":"codeinline","content":[{"type":"text","text":"10bit"}]},{"type":"text","text":" Working process bit and "},{"type":"codeinline","content":[{"type":"text","text":"12bit"}]},{"type":"text","text":" Serial number position . "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/84/84b9668edec202a384f320e51b1939fd.png","alt":" Snowflake algorithm ID form ","title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" Sign bit （1bit position ）"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Java in Long The highest bit of a type is the sign bit , A positive number is 0, Negative number is 1, General generation ID All positive , So the default is 0"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" Time stamp bit （41bit） "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"41 The number of milliseconds a bit's timestamp can hold is 2 Of 41 The next power , And the total number of milliseconds a year is "},{"type":"codeinline","content":[{"type":"text","text":"1000L * 60 * 60 * 24 * 365"}]},{"type":"text","text":", The calculation time is about 69 year , forehead ~, I have enough for my life ."}]},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"Math.pow(2, 41) / (365 * 24 * 60 * 60 * 1000L) = = 69 year "}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" Work progress bit （10bit） "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Represents a unique work process id, The default value is 0, It can be done by "},{"type":"codeinline","content":[{"type":"text","text":"key-generator.props.worker.id"}]},{"type":"text","text":" Property settings ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"spring.shardingsphere.sharding.tables.t_order.key-generator.props.worker.id=0000"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" Serial number position （12bit） "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Different... Are generated in the same millisecond ID."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" Clock back "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Understand the primary key of snowflake algorithm ID It's not hard to find out , This is an algorithm that depends heavily on server time , And those who rely on server time will encounter a thorny problem ："},{"type":"codeinline","content":[{"type":"text","text":" Clock back "}]},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":" Why is there a clock back ？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" There is a network time protocol in the Internet "},{"type":"codeinline","content":[{"type":"text","text":"ntp"}]},{"type":"text","text":" Full name ("},{"type":"codeinline","content":[{"type":"text","text":"Network Time Protocol"}]},{"type":"text","text":") , Specifically used to synchronize 、 Calibrate the time of each computer in the network ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" That's why , Our phones don't have to manually calibrate the time now , But everyone's cell phone time is the same ."}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Our hardware clock may become inaccurate for various reasons （ "},{"type":"codeinline","content":[{"type":"text","text":" fast "}]},{"type":"text","text":" or "},{"type":"codeinline","content":[{"type":"text","text":" slow "}]},{"type":"text","text":" ）, At this point, we need "},{"type":"codeinline","content":[{"type":"text","text":"ntp"}]},{"type":"text","text":" Service to do time calibration , When you do the calibration, the server clock will happen "},{"type":"codeinline","content":[{"type":"text","text":" jumping "}]},{"type":"text","text":" perhaps "},{"type":"codeinline","content":[{"type":"text","text":" Back to dial the "}]},{"type":"text","text":" The problem of ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":" How to solve clock callback by snowflake algorithm "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Server clock callback can cause duplicate ID,"},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":" In the scheme, the original snowflake algorithm is improved , Added a maximum tolerated clock callback in milliseconds ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" If the time of clock callback exceeds the maximum tolerance threshold of milliseconds , The program reports an error directly ; If it's within tolerance , Default distributed primary key generator , It will wait for the clock to synchronize to the time of the last primary key generation before continuing to work ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Maximum number of clock callback milliseconds tolerated , The default value is 0, You can use the properties "},{"type":"codeinline","content":[{"type":"text","text":"max.tolerate.time.difference.milliseconds"}]},{"type":"text","text":" Set up ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"# Maximum number of clock callback milliseconds tolerated \nspring.shardingsphere.sharding.tables.t_order.key-generator.max.tolerate.time.difference.milliseconds=5"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Here is the source code implementation class "},{"type":"codeinline","content":[{"type":"text","text":"SnowflakeShardingKeyGenerator"}]},{"type":"text","text":", The core process is as follows ："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" When the primary key was last generated "},{"type":"codeinline","content":[{"type":"text","text":"lastMilliseconds"}]},{"type":"text","text":" And current time "},{"type":"codeinline","content":[{"type":"text","text":"currentMilliseconds"}]},{"type":"text","text":" compare , If "},{"type":"codeinline","content":[{"type":"text","text":"lastMilliseconds"}]},{"type":"text","text":" > "},{"type":"codeinline","content":[{"type":"text","text":"currentMilliseconds"}]},{"type":"text","text":" It means that the clock is back ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Then judge the difference between the two times （"},{"type":"codeinline","content":[{"type":"text","text":"timeDifferenceMilliseconds"}]},{"type":"text","text":"） Whether the maximum tolerance time threshold is set "},{"type":"codeinline","content":[{"type":"text","text":"max.tolerate.time.difference.milliseconds"}]},{"type":"text","text":" Inside , The thread sleep difference time is within the threshold value "},{"type":"codeinline","content":[{"type":"text","text":"Thread.sleep(timeDifferenceMilliseconds)"}]},{"type":"text","text":", Otherwise, if it is greater than the difference value, it will report an exception directly ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"javascript"},"content":[{"type":"text","text":" \n/**\n * @author xiaofu\n */\npublic final class SnowflakeShardingKeyGenerator implements ShardingKeyGenerator{\n @Getter\n @Setter\n private Properties properties = new Properties();\n \n public String getType() {\n return \"SNOWFLAKE\";\n }\n \n public synchronized Comparable generateKey() {\n \t/**\n \t * Current system time in milliseconds \n \t */ \n long currentMilliseconds = timeService.getCurrentMillis();\n /**\n * Judge whether the waiting time is poor , if necessary , Then the waiting time goes by , And then get the current system time \n */ \n if (waitTolerateTimeDifferenceIfNeed(currentMilliseconds)) {\n currentMilliseconds = timeService.getCurrentMillis();\n }\n /**\n * If the last millisecond and The current system time is the same in milliseconds , In the same millisecond \n */\n if (lastMilliseconds == currentMilliseconds) {\n \t/**\n \t * & Bit and operator ： Both numbers are binary , If all the corresponding bits are 1, The result is 1, Otherwise 0\n \t * When the sequence is 4095 when ,4095+1 After the new sequence and mask bit and operation, the result is 0\n \t * When the sequence is other values , Neither the bits nor the result of the operation will be 0\n \t * That is, the maximum value has been used in this millisecond sequence 4096, At this time, you need to take down a millisecond time value \n \t */\n if (0L == (sequence = (sequence + 1) & SEQUENCE_MASK)) {\n currentMilliseconds = waitUntilNextTime(currentMilliseconds);\n }\n } else {\n \t/**\n \t * The last millisecond has passed , Reset the sequence value to 1 \n \t */\n vibrateSequenceOffset();\n sequence = sequenceOffset;\n }\n lastMilliseconds = currentMilliseconds;\n \n /**\n * XX......XX XX000000 00000000 00000000\t Time difference XX\n * \t\tXXXXXX XXXX0000 00000000\t machine ID XX\n * \t\t XXXX XXXXXXXX\t Serial number XX\n * Three parts | Bitwise OR operation ： If all the corresponding bits are 0, The result is 0, Otherwise 1\n */\n return ((currentMilliseconds - EPOCH) << TIMESTAMP_LEFT_SHIFT_BITS) | (getWorkerId() << WORKER_ID_LEFT_SHIFT_BITS) | sequence;\n }\n \n /**\n * Judge whether the waiting time is poor \n */\n @SneakyThrows\n private boolean waitTolerateTimeDifferenceIfNeed(final long currentMilliseconds) {\n \t/**\n \t * If you get ID The last time in MS is less than or equal to the current system time Ms , It's normal , You don't have to wait \n \t */\n if (lastMilliseconds <= currentMilliseconds) {\n return false;\n }\n /**\n * ===> When the clock goes back （ The time to generate the sequence is longer than that of the current system ）, Need to wait time difference \n */\n /**\n * obtain ID The time difference between the last millisecond of the current system time minus the number of milliseconds of the current system time \n */\n long timeDifferenceMilliseconds = lastMilliseconds - currentMilliseconds;\n /**\n * Time difference is less than the maximum tolerance time difference , That is, it is still within the time difference of clock callback \n */\n Preconditions.checkState(timeDifferenceMilliseconds < getMaxTolerateTimeDifferenceMilliseconds(), \n \"Clock is moving backwards, last time is %d milliseconds, current time is %d milliseconds\", lastMilliseconds, currentMilliseconds);\n /**\n * Thread sleep time difference \n */\n Thread.sleep(timeDifferenceMilliseconds);\n return true;\n }\n \n // Configured machine ID\n private long getWorkerId() {\n long result = Long.valueOf(properties.getProperty(\"worker.id\", String.valueOf(WORKER_ID)));\n Preconditions.checkArgument(result >= 0L && result < WORKER_ID_MAX_VALUE);\n return result;\n }\n \n private int getMaxTolerateTimeDifferenceMilliseconds() {\n return Integer.valueOf(properties.getProperty(\"max.tolerate.time.difference.milliseconds\", String.valueOf(MAX_TOLERATE_TIME_DIFFERENCE_MILLISECONDS)));\n }\n \n private long waitUntilNextTime(final long lastTime) {\n long result = timeService.getCurrentMillis();\n while (result <= lastTime) {\n result = timeService.getCurrentMillis();\n }\n return result;\n }\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" But from "},{"type":"codeinline","content":[{"type":"text","text":"SNOWFLAKE"}]},{"type":"text","text":" The primary key generated by the scheme ID Look at ,"},{"type":"codeinline","content":[{"type":"text","text":"order_id"}]},{"type":"text","text":" It's a 18 A long integer number of bits , Did you find it too long , to want to "},{"type":"codeinline","content":[{"type":"text","text":"MySQL"}]},{"type":"text","text":" That kind of 0 How to realize the incremental self increasing primary key ？ Don't worry. , The solution will be given in the back ！"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/06/06077bd1fd0672c46b8917c5b0b711b0.png","alt":"SNOWFLAKE Primary key ID","title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":" Customize "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"codeinline","content":[{"type":"text","text":"sharding-jdbc"}]},{"type":"text","text":" utilize "},{"type":"codeinline","content":[{"type":"text","text":"SPI"}]},{"type":"text","text":" Full name （ "},{"type":"codeinline","content":[{"type":"text","text":"Service Provider Interface"}]},{"type":"text","text":"） Mechanism to expand the primary key generation rules , This is a service discovery mechanism , By scanning the project path "},{"type":"codeinline","content":[{"type":"text","text":"META-INF/services"}]},{"type":"text","text":" The files under the , And automatically loads the classes defined in the file ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" In fact, it is relatively simple to implement a custom primary key generator , There are only two steps ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" First step , Realization "},{"type":"codeinline","content":[{"type":"text","text":"ShardingKeyGenerator"}]},{"type":"text","text":" Interface , And rewrite its internal methods , among "},{"type":"codeinline","content":[{"type":"text","text":"getType()"}]},{"type":"text","text":" The method is a user-defined primary key production scheme type 、"},{"type":"codeinline","content":[{"type":"text","text":"generateKey()"}]},{"type":"text","text":" The method is to generate the rules of primary key ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The following code uses "},{"type":"codeinline","content":[{"type":"text","text":"AtomicInteger"}]},{"type":"text","text":" To simulate and implement an ordered self increasing ID Generate ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"javascript"},"content":[{"type":"text","text":"/**\n * @Author: xiaofu\n * @Description: Custom key generator \n */\n@Component\npublic class MyShardingKeyGenerator implements ShardingKeyGenerator {\n\n\n private final AtomicInteger count = new AtomicInteger();\n\n /**\n * Custom generation scheme type \n */\n @Override\n public String getType() {\n return \"XXX\";\n }\n\n /**\n * The core approach - Generate primary key ID\n */\n @Override\n public Comparable generateKey() {\n return count.incrementAndGet();\n }\n\n @Override\n public Properties getProperties() {\n return null;\n }\n\n @Override\n public void setProperties(Properties properties) {\n\n }\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The second step , Because of the use of "},{"type":"codeinline","content":[{"type":"text","text":"SPI"}]},{"type":"text","text":" The mechanism realizes the function expansion , We will be having "},{"type":"codeinline","content":[{"type":"text","text":"META-INF/services"}]},{"type":"text","text":" The file is configured with a user-defined primary key generator class ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"com.xiaofu.sharding.key.MyShardingKeyGenerator"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/6a/6a56178a8f7fbd4d35813d74dbc1526c.png","alt":" Custom primary key SPI To configure ","title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" We'll test these things , Configure defined primary key generation type "},{"type":"codeinline","content":[{"type":"text","text":"XXX"}]},{"type":"text","text":", And insert a few pieces of data to see the effect ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"spring.shardingsphere.sharding.tables.t_order.key-generator.column=order_id\nspring.shardingsphere.sharding.tables.t_order.key-generator.type=XXX"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Through the console SQL Parsing logs found ,"},{"type":"codeinline","content":[{"type":"text","text":"order_id"}]},{"type":"text","text":" The field has been inserted into the record in an ordered auto increment manner , It shows that the configuration is OK ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/fa/fa85d1e74617da14b5e7fea736e14ab4.png","alt":null,"title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":" Take one against nine "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Since you can customize the generation scheme , So there are many ways to realize distributed primary keys , I think of this one I wrote before "},{"type":"link","attrs":{"href":"https://mp.weixin.qq.com/s?_biz=MzAxNTM4NzAyNg==&mid=2247483785&idx=1&sn=8b828a8ae1701b810fe3969be536cb14&chksm=9b859174acf21862f0b95e0502a1a441c496a5488f5466b2e147d7bb9de072bde37c4db25d7a&token=113284294&lang=zhCN#rd","title":""},"content":[{"type":"text","text":"《9 Kind of Distributed ID Generation scheme 》"}]},{"type":"text","text":", Discover that it can be perfectly compatible with , Here's a selection of sound of dripping water （"},{"type":"codeinline","content":[{"type":"text","text":"Tinyid"}]},{"type":"text","text":"） Let's practice , Because it's a separate distributed ID Build service , So we have to build the environment first ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"codeinline","content":[{"type":"text","text":"Tinyid"}]},{"type":"text","text":" Service provision of "},{"type":"codeinline","content":[{"type":"text","text":"Http"}]},{"type":"text","text":" and "},{"type":"codeinline","content":[{"type":"text","text":"Tinyid-client"}]},{"type":"text","text":" Two access modes , Use below "},{"type":"codeinline","content":[{"type":"text","text":"Tinyid-client "}]},{"type":"text","text":" Way to use quickly , Read more details in this article , It's been introduced too many times ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"Tinyid Service establishment "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" First pull the source code "},{"type":"codeinline","content":[{"type":"text","text":"https://github.com/didi/tinyid.git"}]},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Because it is distributed based on the segment pattern ID, So it depends on the database , To create the corresponding table "},{"type":"codeinline","content":[{"type":"text","text":"tiny_id_info"}]},{"type":"text","text":" 、"},{"type":"codeinline","content":[{"type":"text","text":"tiny_id_token"}]},{"type":"text","text":" And insert the default data ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"sql"},"content":[{"type":"text","text":"\nCREATE TABLE `tiny_id_info` (\n\t`id` BIGINT (20) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT ' Since the primary key ',\n\t`biz_type` VARCHAR (63) NOT NULL DEFAULT '' COMMENT ' Business types , only ',\n\t`begin_id` BIGINT (20) NOT NULL DEFAULT '0' COMMENT ' Start id, Record only the initial value , No other meaning . On initialization begin_id and max_id It should be the same ',\n\t`max_id` BIGINT (20) NOT NULL DEFAULT '0' COMMENT ' At present, the biggest id',\n\t`step` INT (11) DEFAULT '0' COMMENT ' step ',\n\t`delta` INT (11) NOT NULL DEFAULT '1' COMMENT ' Every time id The incremental ',\n\t`remainder` INT (11) NOT NULL DEFAULT '0' COMMENT ' remainder ',\n\t`create_time` TIMESTAMP NOT NULL DEFAULT '2010-01-01 00:00:00' COMMENT ' Creation time ',\n\t`update_time` TIMESTAMP NOT NULL DEFAULT '2010-01-01 00:00:00' COMMENT ' Update time ',\n\t`version` BIGINT (20) NOT NULL DEFAULT '0' COMMENT ' Version number ',\n\tPRIMARY KEY (`id`),\n\tUNIQUE KEY `uniq_biz_type` (`biz_type`)\n) ENGINE = INNODB AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8 COMMENT 'id Information sheet ';\n\nCREATE TABLE `tiny_id_token` (\n\t`id` INT (11) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT ' Self increasing id',\n\t`token` VARCHAR (255) NOT NULL DEFAULT '' COMMENT 'token',\n\t`biz_type` VARCHAR (63) NOT NULL DEFAULT '' COMMENT ' this token Accessible business type ID ',\n\t`remark` VARCHAR (255) NOT NULL DEFAULT '' COMMENT ' remarks ',\n\t`create_time` TIMESTAMP NOT NULL DEFAULT '2010-01-01 00:00:00' COMMENT ' Creation time ',\n\t`update_time` TIMESTAMP NOT NULL DEFAULT '2010-01-01 00:00:00' COMMENT ' Update time ',\n\tPRIMARY KEY (`id`)\n) ENGINE = INNODB AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8 COMMENT 'token Information sheet ';\n\nINSERT INTO `tiny_id_token` (`id`, `token`, `biz_type`, `remark`, `create_time`, `update_time`) VALUES ('1', '0f673adf80504e2eaa552f5d791b644c', 'order', '1', '2017-12-14 16:36:46', '2017-12-14 16:36:48');\n\nINSERT INTO `tiny_id_info` (`id`, `biz_type`, `begin_id`, `max_id`, `step`, `delta`, `remainder`, `create_time`, `update_time`, `version`) VALUES ('1', 'order', '1', '1', '100000', '1', '0', '2018-07-21 23:52:58', '2018-07-22 23:19:27', '1');\n"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" And in "},{"type":"codeinline","content":[{"type":"text","text":"Tinyid"}]},{"type":"text","text":" Configure the data source information of the upper table in the service "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"sql"},"content":[{"type":"text","text":"datasource.tinyid.primary.url=jdbc:mysql://47.93.6.e:3306/ds-0?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8\ndatasource.tinyid.primary.username=root\ndatasource.tinyid.primary.password=root"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The final project "},{"type":"codeinline","content":[{"type":"text","text":"maven install"}]},{"type":"text","text":" , Right click "},{"type":"codeinline","content":[{"type":"text","text":"TinyIdServerApplication"}]},{"type":"text","text":" Start the service , "},{"type":"codeinline","content":[{"type":"text","text":"Tinyid"}]},{"type":"text","text":" Distributed ID The build service is finished ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" Customize Tinyid Primary key type "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"codeinline","content":[{"type":"text","text":"Tinyid"}]},{"type":"text","text":" After the service is built, we will introduce it into the project , Create a new "},{"type":"codeinline","content":[{"type":"text","text":"tinyid_client.properties"}]},{"type":"text","text":" Add... To the file "},{"type":"codeinline","content":[{"type":"text","text":"tinyid.server"}]},{"type":"text","text":" and "},{"type":"codeinline","content":[{"type":"text","text":"tinyid.token"}]},{"type":"text","text":" attribute ,"},{"type":"codeinline","content":[{"type":"text","text":"token"}]},{"type":"text","text":" Before SQL Pre inserted user data ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"# tinyid Distributed ID\n# Service address \ntinyid.server=127.0.0.1:9999\n# Business token\ntinyid.token=0f673adf80504e2eaa552f5d791b644c"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Get in code ID It's simpler , Just one line of code , Business types "},{"type":"codeinline","content":[{"type":"text","text":"order"}]},{"type":"text","text":" Before SQ L Pre inserted data ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"java"},"content":[{"type":"text","text":"Long id = TinyId.nextId(\"order\");"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" We started customizing "},{"type":"codeinline","content":[{"type":"text","text":" Tinyid"}]},{"type":"text","text":" Implementation class of primary key generation type "},{"type":"codeinline","content":[{"type":"text","text":"TinyIdShardingKeyGenerator "}]},{"type":"text","text":" ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"java"},"content":[{"type":"text","text":"/**\n * @Author: xiaofu\n * @Description: Custom key generator \n */\n@Component\npublic class TinyIdShardingKeyGenerator implements ShardingKeyGenerator {\n \n /**\n * Custom generation scheme type \n */\n @Override\n public String getType() {\n return \"tinyid\";\n }\n\n /**\n * The core approach - Generate primary key ID\n */\n @Override\n public Comparable generateKey() {\n \n Long id = TinyId.nextId(\"order\");\n \n return id;\n }\n\n @Override\n public Properties getProperties() {\n return null;\n }\n\n @Override\n public void setProperties(Properties properties) {\n\n }\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" And enable... In the configuration file "},{"type":"codeinline","content":[{"type":"text","text":" Tinyid"}]},{"type":"text","text":" Primary key generation type , This is the end of the configuration , Test it quickly ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":""},"content":[{"type":"text","text":"# Primary key field \nspring.shardingsphere.sharding.tables.t_order.key-generator.column=order_id\n# Primary key ID Generation scheme \nspring.shardingsphere.sharding.tables.t_order.key-generator.type=tinyid"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":" test Tinyid Primary key "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Insert the order record into the database and test it , Primary key ID Field "},{"type":"codeinline","content":[{"type":"text","text":"order_id"}]},{"type":"text","text":" It's increasing for the trend , "},{"type":"codeinline","content":[{"type":"text","text":" Tinyid"}]},{"type":"text","text":" The service was successfully connected to , perfect ！"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/26/26a5e37467173714105788c558b4cb36.png","alt":" Insert picture description here ","title":null,"style":null,"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":" summary "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The following eight generation methods are referred to "},{"type":"link","attrs":{"href":"https://mp.weixin.qq.com/s?_biz=MzAxNTM4NzAyNg==&mid=2247483785&idx=1&sn=8b828a8ae1701b810fe3969be536cb14&chksm=9b859174acf21862f0b95e0502a1a441c496a5488f5466b2e147d7bb9de072bde37c4db25d7a&token=113284294&lang=zhCN#rd","title":""},"content":[{"type":"text","text":"《9 Kind of Distributed ID Generation scheme 》"}]},{"type":"text","text":" Access on demand , It is relatively simple as a whole, and it is not implemented in turn here ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Case study GitHub Address ：https://github.com/chengxy-nds/Springboot-Notebook/tree/master/springboot-sharding-jdbc"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" If it works for you , welcome Looking at 、 give the thumbs-up 、 forward , Your approval is my biggest motivation ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Hundreds of e-book technologies have been sorted out , To my friends . Pay attention to the public name and reply "},{"type":"text","marks":[{"type":"strong"}],"text":"666"},{"type":"text","text":" Get it yourself . Set up a technology exchange group with some friends , Discuss technology together 、 Share technical information , It aims to learn and improve together , If you are interested, please join us ！"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}}]}