Data processing method, distributed database system, electronic device and storage medium

1 . A data processing method, applied to a shard node of a distributed database system, comprising:

receiving a physical DDL instruction converted from a logic DDL instruction for change of data in the distributed database system;

executing the physical DDL instruction and generating a shard node mode snapshot for the shard node after the physical DDL instruction has been successfully executed, wherein the shard node mode snapshot corresponding to a shard node mode that is changed after the shard node has successfully executed the physical DDL instruction, wherein for each shard node, a shard node mode snapshot is generated for the shard node after the shard node has successfully executed the physical DDL instruction, and wherein the shard node mode snapshot describes logic structure and features of data stored in the corresponding shard node after the shard node has successfully executed the physical DDL instruction;

comparing the shard node mode snapshot with a global logic mode snapshot of the distributed database system, wherein the global logic mode snapshot corresponding to a global logic mode that is changed after all shard nodes in the database system have successfully executed the physical DDL instruction, wherein the global logic mode snapshot describes logic structure and features of all data stored in the all shard nodes in the database system; and

determining that the shard node mode snapshot is inconsistent with the global logic mode snapshot, adjusting log data of the shard node aggregated into a global log to be consistent with the global logic mode snapshot.

2 . The method of claim 1 , wherein the generating the shard node mode snapshot for the shard node after the physical DDL instruction has been successfully executed, comprises:

after the physical DDL instruction has been successfully executed, generating, in the log data of the shard node, a DDL event indicating that the physical DDL instruction has been successfully executed by the shard node, so as to generate the shard node mode snapshot for the shard node that has successfully executed the physical DDL instruction based on the DDL event.

3 . The method of claim 2 , further comprising:

inserting a corresponding DDL marking event into the log data of the shard node for indicating successful completion of the logic DDL instruction after all shard nodes have successfully executed respective physical DDL instructions, and receiving the corresponding DDL marking event, wherein the DDL marking event has information of TSO of the distributed database system and the DDL marking event of the shard node has the same TSO as DDL marking event of other shard node.

4 . The method of claim 3 , wherein the inserting the corresponding DDL marking event into the log data of the shard node for indicating successful completion of the logic DDL instruction, comprises:

inserting event data into the log data of the shard node for indicating that the logic DDL instruction has been successfully executed, the event data containing content data of the logic DDL instruction.

5 . The method of claim 1 , further comprising:

inserting a corresponding DDL marking event into the log data of the shard node for indicating successful completion of the logic DDL instruction after all shard nodes have successfully executed respective physical DDL instructions, and receiving the corresponding DDL marking event, wherein the DDL marking event has information of TSO of the distributed database system and the DDL marking event of the shard node has the same TSO as DDL marking event of other shard node.

6 . The method of claim 5 , wherein the inserting the corresponding DDL marking event into the log data of the shard node for indicating successful completion of the logic DDL instruction, comprises:

inserting event data into the log data of the shard node for indicating that the logic DDL instruction has been successfully executed, the event data containing content data of the logic DDL instruction.

7 . An electronic device, comprising: a processor, a memory, a communication interface and a communication bus, the processor, the memory and the communication interface communicating with one another through the communication bus;

wherein the memory is provided for storing at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the data processing method of claim 1 .

8 . A non-transitory computer storage medium stored with computer programs thereon, wherein the computer programs, when executed by a processor, implement the data processing method of claim 1 .

9 . A computer program product, comprising computer instructions, wherein the computer instructions instruct a computing device to perform operations corresponding to the data processing method of claim 1 .

10 . A data processing method, applied to a middleware node of a distributed database system, comprising:

receiving a logic DDL instruction for change of data in the distributed database system and converting the logic DDL instruction into a physical DDL instruction; and

issuing the physical DDL instruction to a corresponding shard node to allow the shard node to execute the physical DDL instruction; and after successful execution of the physical DDL instruction, adjusting log data of the shard node aggregated into a global log based on a consistency relation between a shard node mode snapshot generated for the shard node and a global logic mode snapshot obtained, such that the log data of the shard node aggregated into the global log is consistent with the global logic mode snapshot;

wherein the shard node mode snapshot corresponding to a shard node mode that is changed after the shard node has successfully executed the physical DDL instruction, wherein for each shard node, a shard node mode snapshot is generated for the shard node after the shard node has successfully executed the physical DDL instruction, and wherein the shard node mode snapshot describes logic structure and features of data stored in the corresponding shard node after the shard node has successfully executed the physical DDL instruction; and the global logic mode snapshot corresponding to a global logic mode that is changed after all shard nodes in the database system have successfully executed the physical DDL instruction, wherein the global logic mode snapshot describes logic structure and features of all data stored in the all shard nodes in the database system.

11 . The method of claim 10 , wherein the method further comprises:

receiving a DDL marking event generated after the respective shard node has successfully executed the physical DDL instruction for indicating successful execution of the logic DDL instruction, and creating the global logic mode snapshot corresponding to the DDL marking event.

12 . The method of claim 11 , wherein the DDL marking event in the log data of the respective shard node has information of TSO of the distributed database system, and the DDL marking event of the respective shard node has the same TSO; and

the receiving the DDL marking event generated after the respective shard has successfully executed the physical DDL instruction for indicating successful execution of the logic DDL instruction comprises: merging the DDL marking event corresponding to the respective shard node based on the information of the TSO corresponding to the DDL marking event in the log data of the respective shard node; and generating a logic DDL event in a global log based on a merging result.

13 . The method of claim 11 , wherein the method further comprises: after the receiving the logic DDL instruction for change of data in the distributed database system,

determining an execution rule for the logic DDL instruction based on a type of the logic DDL instruction.

14 . The method of claim 10 , wherein the method further comprises: after the receiving the logic DDL instruction for change of data in the distributed database system,

determining an execution rule for the logic DDL instruction based on a type of the logic DDL instruction.

15 . The method of claim 14 , wherein the determining the execution rule for the logic DDL instruction based on the type of the logic DDL instruction comprises:

if the logic DDL instruction is of a type where new mode is compatible with old mode, determining the execution rule of the logic DDL instruction as: issuing the physical DDL instruction to the shard node; generating the DDL marking event for indicating successful execution of the logic DDL instruction after all shard nodes have successfully executed the physical DDL instruction; and setting the new mode to be externally visible after the DDL marking event.

16 . The method of claim 14 , wherein the determining the execution rule for the logic DDL instruction based on the type of the logic DDL instruction comprises:

if the logic DDL instruction is of a type where old mode is compatible with new mode, determining the execution rule of the logic DDL instruction as: setting the new mode to be externally visible; then issuing the physical DDL instruction to the shard node; and generating a DDL marking event for indicating successful execution of the logic DDL instruction after all shard nodes have successfully executed the physical DDL instruction.

17 . An electronic device, comprising: a processor, a memory, a communication interface and a communication bus, the processor, the memory and the communication interface communicating with one another through the communication bus;

wherein the memory is provided for storing at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the data processing method of claim 10 .

18 . A non-transitory computer storage medium stored with computer programs thereon, wherein the computer programs, when executed by a processor, implement the data processing method of claim 10 .

19 . A computer program product, comprising computer instructions, wherein the computer instructions instruct a computing device to perform operations corresponding to the data processing method of claim 10 .

20 . A distributed database system, comprising a middleware node and a shard node, wherein:

the middleware node is provided for receiving a logic DDL instruction for change of data in the distributed database system, converting the logic DDL instruction into a physical DDL instruction and issuing the physical DDL instruction to the corresponding shard node; and

the shard node is provided for executing the physical DDL instruction and generating a shard node mode snapshot for the shard node after successful execution of the physical DDL instruction; it is determined that the shard node mode snapshot is inconsistent with a global logic mode snapshot of the distributed database system, log data of the shard node aggregated into the global log is adjusted to be consistent with the global logic mode snapshot;

wherein the shard node mode snapshot corresponding to a shard node mode that is changed after the shard node has successfully executed the physical DDL instruction, wherein for each shard node, a shard node mode snapshot is generated for the shard node after the shard node has successfully executed the physical DDL instruction, and wherein the shard node mode snapshot describes logic structure and features of data stored in the corresponding shard node after the shard node has successfully executed the physical DDL instruction; and the global logic mode snapshot corresponding to a global logic mode that is changed after all shard nodes in the database system have successfully executed the physical DDL instruction, wherein the global logic mode snapshot describes logic structure and features of all data stored in the all shard nodes in the database system.