Distributed database system, transaction processing method, lock server and storage medium

Patent metadata

Field	Value
Publication number	US-2019155795-A1
Application number	US-201916251401-A
Country	US
Kind code	A1
Filing date	Jan 18, 2019
Priority date	Oct 24, 2016
Publication date	May 23, 2019
Grant date	—

Abstract

A distributed database system may include storage layer. The storage layer may partition data and store the partitioned data in a distributed database. The system may further include access layer. The access layer may receive a transaction, identify target data corresponding to the transaction, and generate a lock request to lock the target data included in the partitioned data. The system may further include lock service layer. The lock service layer may identify, based on the lock request, a lock status for the target data according to a lock record for the target data. The lock service layer may lock, in response to the lock status being in an unlocked state, the target data. The lock service layer may block, in response to the lock status being in a locked state, the lock request and store the lock request in a queue.

First claim

What is claimed is:

1 . A distributed database system, comprising:
a storage layer executable by a processor to partition data and store the partitioned data in a distributed database; an access layer executable by a processor to receive a transaction, identify target data corresponding to the transaction, and generate a lock request to lock the target data included in the partitioned data; and lock service layer executable by a processor to:
identify, based on the lock request, a lock status for the target data according to a lock record for the target data,
lock, in response to the lock status being in an unlocked state, the target data, and
block, in response to the lock status being in a locked state, the lock request and store the lock request in a queue.

2 . The distributed database system of claim 1 , wherein the lock service layer is further executable by the processor to:
determine that the lock status for the target data is in the locked state in response to generation of the lock record for the target data; and set the lock status for the target data to the unlocked state in response to detection that the lock record was deleted.

3 . The distributed database system of claim 1 , wherein the lock service layer is further executable by the processor to:
notify, in response to determination that the lock status for the target data is no longer in the locked state, the storage layer that access to the target data is allowed only during execution of the transaction.

4 . The distributed database system of claim 1 , wherein
the lock service layer is further executable by the processor to:
determine that the lock status for the target data is no longer in the locked state;
dequeue the lock request corresponding to the transaction;
set the lock status for the target data to the locked state;
instruct the access layer to commit the transaction to the storage layer,
permit the storage layer is further executable by the processor to access the locked target data in response to execution of the transaction.

5 . The distributed database system of claim 1 , wherein
the access layer is further executable by the processor to commit, in response to determination that the lock status for target data is in the locked state and the storage layer has completed execution of a historical transaction on the target data, the transaction corresponding to the lock request.

6 . The distributed database system of claim 1 , wherein the lock service layer is further executable by the processor to generate the lock record for the target data when the lock status for target data is not in the locked state, and remove the lock record for the target data when the storage layer has completed the execution of the transaction.

7 . The distributed database system of claim 1 , wherein
the access layer is further executable by the processor to commit an initiated operation to the storage layer, and in response to failure to execute the operation by the storage layer, convert the initiated operation into the transaction, and instruct the lock service layer to lock target data corresponding to the transaction.

8 . The distributed database system of claim 7 , wherein
the lock service layer is further executable by the processor to instruct, in response to determination that the target data is no longer in the locked state and the storage layer has completed execution of a historical transaction on the target data, the access layer to commit the transaction corresponding to the lock request stored in the queue to the storage layer.

9 . The distributed database system of claim 8 , wherein the lock service layer is further executable by the processor to instruct the storage layer to lock the target data.

10 . A database transaction processing method, comprising:
receiving a transaction to access target data stored in a distributed database; generating a lock request in response to receipt of the transaction; determining the target data is in a locked state based on a lock record for the target data; and in response to determination that the target data is in the locked state:
blocking execution of the transaction, and
storing the lock request in a queue corresponding to the target data.

11 . The database transaction processing method of claim 10 , wherein determining the target data stored in a distributed database is in a locked state further comprises:
identifying a lock record corresponding to the target data; and determining that the target data is in the locked state in response to identification of the lock record.

12 . The database transaction processing method of claim 10 , wherein blocking execution of the transaction further comprises:
denying a permission to access the target data with the transaction in response to concurrent execution of a previous transaction configured to access the target data.

13 . The database transaction processing method of claim 10 , wherein the method further comprises:
determining the target data stored in a distributed database is no longer in the locked state based on a lock record of the target data; and committing the transaction in response to determination that the target data is not in the locked state.

14 . The database transaction processing method of claim 10 , wherein the method further comprises:
generating a lock record for the target data when the target data is not in the locked state; and deleting the lock record for the target data when the execution of the transaction is completed.

15 . The database transaction processing method of claim 14 , wherein the method further comprises:
determining the target data stored in a distributed database is no longer in a locked state based on a lock record of the target data; and determining that execution of a historical transaction on the target data is completed; committing, in response to determination that the target data is no longer in the locked state and the execution of the historical transaction on the target data is completed, the transaction corresponding to the lock request stored in the queue.

16 . The database transaction processing method of claim 15 , wherein the method further comprises:
determining the target data stored in a distributed database is no longer in a locked state based on a lock record of the target data; and dequeueing the lock request in response to determination that the target data stored in the distributed database is no longer in the locked state; and locking the target data based on the lock request.

17 . A lock server comprising:
a processor, the processor configured to: receive a lock request indicative of target data accessed to execute a database transaction; determine, based on a lock record for the target data, that the target data is in a locked state; block, in response to the target data being in the locked state, execution of the database transaction; and store the lock request in a queue corresponding to the target data.

18 . The lock server according to claim 17 , wherein the processor is further configured to
identify the lock record for the target data; determine that the target data is in a locked state in response to identification of the lock record; and determine that the target data is no longer in the locked state in response to deletion of the lock record.

19 . The lock server according to claim 17 , wherein the processor is further configured to deny a permission to access the target data in accordance w

Assignees

• Tencent Tech Shenzhen Co Ltd

Inventors

• Xiao Tao

Classifications

• G06F9/526

  Mutual exclusion algorithms · CPC title

• G06F16/28 Primary

  Databases characterised by their database models, e.g. relational or object models · CPC title

• G06F16/211 Primary

  Schema design and management · CPC title

• G06F9/52

  Program synchronisation; Mutual exclusion, e.g. by means of semaphores · CPC title

• G06F16/27 Primary

  Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor · CPC title