CN114328376A

CN114328376A - Snapshot creating method, device, equipment and storage medium

Info

Publication number: CN114328376A
Application number: CN202011079399.9A
Authority: CN
Inventors: 金振成
Original assignee: Tencent Technology Shenzhen Co Ltd
Current assignee: Tencent Technology Shenzhen Co Ltd
Priority date: 2020-10-10
Filing date: 2020-10-10
Publication date: 2022-04-12

Abstract

The application discloses a snapshot creating method, a snapshot creating device, snapshot creating equipment and a storage medium. The method comprises the following steps: acquiring a snapshot creating request, wherein the snapshot creating request is used for indicating that a snapshot is created for at least one target storage unit; setting the global state of the system to be a writing-inhibited state based on the snapshot creation request, wherein the writing-inhibited state is used for indicating that data writing operation corresponding to all storage units is blocked; performing memory data synchronization operation on at least one target storage unit based on the write-inhibit state; and creating a snapshot for at least one target storage unit which executes the memory data synchronization operation. Based on the mode, when the snapshot is created, the data actually stored in the target storage unit is completely consistent with the data which should be theoretically stored, so that the reliability of the data in the snapshot created by the target storage unit can be improved, the backup effect of the data in the database is favorably improved, and the accuracy of data recovery based on the created snapshot is favorably improved.

Description

Snapshot creating method, device, equipment and storage medium

Technical Field

The embodiment of the application relates to the technical field of computers, in particular to a snapshot creating method, a snapshot creating device, snapshot creating equipment and a storage medium.

Background

A snapshot is a fully available copy of a specified set of data in a database that includes an image of the corresponding data at some point in time. The snapshot technology is a method for effectively protecting data, and can quickly realize data backup. When the application failure or file damage occurs to the storage unit, data recovery can be carried out based on the snapshot technology.

In the related art, after receiving a snapshot creation request of a terminal, a server directly creates a snapshot for a storage unit where the snapshot is to be created. Based on the mode, when the snapshot is created, the data actually stored by the storage unit may not be consistent with the data which should be theoretically stored, the reliability of the data in the snapshot created by the storage unit is poor, and the accuracy of data recovery based on the created snapshot is low.

Disclosure of Invention

The embodiment of the application provides a snapshot creating method, a snapshot creating device, snapshot creating equipment and a storage medium, which can be used for improving the reliability of data in created snapshots. The technical scheme is as follows:

in one aspect, an embodiment of the present application provides a snapshot creating method, where the method includes:

acquiring a snapshot creating request, wherein the snapshot creating request is used for indicating that a snapshot is created for at least one target storage unit;

setting the global state of the system to be a writing-prohibited state based on the snapshot creation request, wherein the writing-prohibited state is used for indicating that data writing operation corresponding to all storage units is blocked;

performing a memory data synchronization operation on the at least one target storage unit based on the write-inhibit status;

and creating a snapshot for at least one target storage unit which executes the memory data synchronization operation.

In one possible implementation, the performing the memory data synchronization operation on the at least one target storage unit includes:

determining target memory data corresponding to any target storage unit in data in a memory, and synchronizing the target memory data to any target storage unit.

In another aspect, a snapshot creation apparatus is provided, the apparatus including:

the system comprises an acquisition module, a storage module and a control module, wherein the acquisition module is used for acquiring a snapshot creation request which is used for indicating that a snapshot is created for at least one target storage unit;

a setting module, configured to set a global state of a system to a write-inhibit state based on the snapshot creation request, where the write-inhibit state is used to indicate that data write operations corresponding to all storage units are blocked;

an operation execution module, configured to execute a memory data synchronization operation on the at least one target storage unit based on the write-inhibit status;

and the creating module is used for creating a snapshot for at least one target storage unit which executes the memory data synchronization operation.

In a possible implementation manner, the setting module is further configured to set, in the write-prohibited state, a state of the at least one target storage unit to a to-be-created snapshot state;

and the operation execution module is used for executing memory data synchronization operation on the at least one target storage unit in the snapshot state to be created.

In a possible implementation manner, the setting module is further configured to, in response to that the states of the at least one target storage unit are the to-be-created snapshot states, restore the global state of the system to a non-write-inhibit state, where the non-write-inhibit state is used to indicate that a data write operation corresponding to a storage unit in which the non-to-be-created snapshot state is restored.

In a possible implementation manner, the setting module is further configured to restore the state of the at least one target storage unit that has created the snapshot to the non-snapshot-to-be-created state.

In a possible implementation manner, the creating module is configured to, in response to that any target storage unit completes execution of the memory data synchronization operation, call a snapshot creating interface corresponding to the any target storage unit to create a snapshot for the any target storage unit.

In a possible implementation manner, the operation execution module is configured to determine, from data in a memory, target memory data corresponding to any target storage unit, and synchronize the target memory data to the any target storage unit.

In a possible implementation manner, the obtaining module is further configured to obtain a data write request, where the data write request is used to instruct to process a data write operation corresponding to the at least one target storage unit;

the operation execution module is further configured to block a data write operation corresponding to the at least one target storage unit in response to that the global state of the system is the write-inhibit state.

the operation executing module is further configured to respond to that the global state of the system is the non-write-inhibit state, block a data write operation corresponding to the target storage unit in the to-be-created snapshot state, and execute the data write operation corresponding to the target storage unit in the non-to-be-created snapshot state.

In another aspect, a computer device is provided, which includes a processor and a memory, where at least one program code is stored in the memory, and the at least one program code is loaded and executed by the processor to implement any one of the snapshot creation methods described above.

In another aspect, a computer-readable storage medium is provided, in which at least one program code is stored, and the at least one program code is loaded and executed by a processor to implement any of the snapshot creation methods described above.

In another aspect, a computer program product or a computer program is also provided, comprising computer instructions stored in a computer readable storage medium. The processor of the computer device reads the computer instructions from the computer readable storage medium, and executes the computer instructions, so that the computer device executes any one of the snapshot creating methods described above.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects:

in the embodiment of the application, before the snapshot is created for the target storage unit, the memory data synchronization operation is executed on the target storage unit based on the write-inhibit state, so that when the snapshot is created, the data actually stored in the target storage unit is completely consistent with the data which should be theoretically stored, and the temporary unsynchronized memory data cannot be lacked, and the newly added data cannot be included.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of an implementation environment of a snapshot creation method provided by an embodiment of the present application;

fig. 2 is a flowchart of a snapshot creation method provided in an embodiment of the present application;

FIG. 3 is a diagram illustrating a process of snapshot creation provided by an embodiment of the present application;

fig. 4 is a schematic diagram of a processing procedure after a data write request is obtained according to an embodiment of the present application;

fig. 5 is a schematic diagram of a snapshot creation apparatus according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a server according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

In order to facilitate understanding of the technical processes of the embodiments of the present application, the following explains the terms referred to in the embodiments of the present application:

snapshot: the definition of Storage Network Industry Association (SNIA) about snapshots is: a snapshot is a fully available copy of a given data set that includes an image of the corresponding data at some point in time (the point in time at which the copy began). A snapshot may be a copy (or replica) of data. The snapshot is a data backup of the storage unit at a certain moment, and data writing and modification in the storage unit cannot affect the created snapshot. Based on the characteristic, the user can use the snapshot to record the data at different moments in the storage unit, so as to meet the requirements of system recovery, disaster recovery, cloud hard disk replication and the like. The snapshot can be used for data backup of a database in the cloud technology field.

Cloud technology: the management method is a management technology for unifying series resources such as hardware, software, network and the like in a wide area network or a local area network to realize the calculation, storage, processing and sharing of data. The cloud technology is based on the general names of network technology, information technology, integration technology, management platform technology, application technology and the like applied in the cloud computing business model, can form a resource pool, is used as required, and is flexible and convenient. Cloud computing technology will become an important support. Background services of the technical network system require a large amount of computing and storage resources, such as video websites, picture-like websites and more web portals. With the high development and application of the internet industry, each article may have its own identification mark and needs to be transmitted to a background system for logic processing, data in different levels are processed separately, and various industrial data need strong system background support and can only be realized through cloud computing.

In the field of cloud technology, the application of databases is crucial. In short, the database can be regarded as an electronic file cabinet, namely a place for storing electronic files, and a user can perform operations such as adding, inquiring, updating, deleting, backing up and the like on data in the files. A "database" is a collection of data that is stored together in a manner that can be shared by multiple users, has as little redundancy as possible, and is independent of the application. In an exemplary embodiment, the backup of data may be accomplished by creating snapshots.

A Database Management System (DBMS) is a computer software System designed for managing a Database, and generally has basic functions such as storage, interception, security assurance, and backup. The database management system may be categorized according to the database model it supports, such as relational, XML (Extensible Markup Language); or classified according to the type of computer supported, e.g., server cluster, mobile phone; or classified according to the Query Language used, such as SQL (Structured Query Language), XQuery (X Query); or by performance impulse emphasis, e.g., maximum size, maximum operating speed; or other classification schemes. Regardless of the manner of classification used, some DBMSs are capable of supporting multiple query languages across categories, for example, simultaneously.

Referring to fig. 1, a schematic diagram of an implementation environment of the snapshot creation method provided in the embodiment of the present application is shown. The implementation environment may include: the terminal 11 and the server 12, and at least one storage unit 121 is mounted on the server 12.

The terminal 11 refers to an operation terminal of a user, and the user can write data, read data, modify data, and the like through the terminal 11. The server 12 is a service server of the terminal 11, and the server 12 is configured to process a processing request sent by the terminal 11, where the processing request sent by the terminal 11 includes, but is not limited to, a data write request, a data read request, and the like. At least one storage unit 121 mounted on the server 12 is used for storing data to be stored in the terminal 11, and the server 12 can store the data in the storage unit 121 according to a data writing request sent by the terminal 11; the server 12 can also read data from the storage unit 121 to return to the terminal 11 in accordance with a data read request sent by the terminal 11.

In one possible implementation, the terminal 11 is any electronic product capable of performing human-computer interaction with a user through one or more modes of a keyboard, a touch pad, a touch screen, a remote controller, voice interaction or handwriting equipment, such as, but not limited to, a smart phone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, and the like. The server 12 is an independent physical server, or a server cluster or a distributed system formed by a plurality of physical servers, or a cloud server providing basic cloud computing services such as a cloud service, a cloud database, cloud computing, a cloud function, cloud storage, a web service, cloud communication, middleware service, a domain name service, a security service, a CDN (Content Delivery Network), and a big data and artificial intelligence platform. The terminal 11 and the server 12 are directly or indirectly connected by wired or wireless communication, and the present application is not limited thereto. The storage unit 121 refers to a unit having a storage function, and exemplarily, the storage unit 121 refers to a storage volume, a magnetic disk, or the like.

It should be understood by those skilled in the art that the above-mentioned terminal 11 and server 12 are only examples, and other existing or future terminals or servers may be suitable for the present application and are included within the scope of the present application and are herein incorporated by reference.

Based on the implementation environment shown in fig. 1, an embodiment of the present application provides a snapshot creating method, which is applied to the server 12 as an example. As shown in fig. 2, the method provided in the embodiment of the present application includes the following steps:

in step 201, a snapshot creation request is obtained, where the snapshot creation request is used to instruct to create a snapshot for at least one target storage unit.

In the embodiment of the present application, the storage unit that needs to create the snapshot and is indicated by the snapshot creation request is taken as the target storage unit. The number of target storage units that need to create a snapshot indicated by one snapshot creation request may be one or more, which is not limited in the embodiment of the present application.

The storage unit is a unit with a storage function mounted on the server, and in the embodiment of the present application, a setting manner of one storage unit is not limited, and exemplarily, one storage unit is one disk; alternatively, a storage unit refers to a storage volume or the like constituted by a set of disks. In the embodiment of the application, each storage unit is an independent individual capable of creating a snapshot, and creating a snapshot for one storage unit refers to creating a snapshot for each component of the storage unit at the same time when one storage unit includes a plurality of components.

In one possible implementation, the at least one target storage unit refers to a storage unit for storing related data, for example, the at least one target storage unit is a storage unit for storing all data generated in a same application. It should be noted that different target storage units may be used for storing the same data, and may also be used for storing different data, which is not limited in the embodiment of the present application. In an exemplary embodiment, at least one target storage unit constitutes a target storage unit group, and creating a snapshot for the at least one target storage unit is creating a snapshot for the target storage unit group.

In an exemplary embodiment, the at least one target storage unit refers to each disk constituting a RAID (Redundant Arrays of Independent Disks). Assuming that the RAID is composed of a disk a, a disk B, and a disk C, the at least one target storage unit refers to the disk a, the disk B, and the disk C, and creating a snapshot for the at least one target storage unit is to create a snapshot for the disk a, the disk B, and the disk C, respectively.

In one possible implementation manner, the manner in which the server obtains the snapshot creation request is as follows: the server acquires a snapshot creation request initiated by the terminal. The terminal here refers to any terminal that needs a server to provide a data storage service, and the server can store data in the terminal in a storage unit mounted on the server. In one possible implementation manner, the manner in which the terminal initiates the snapshot creation request includes, but is not limited to, the following two manners:

mode 1: the terminal initiates a snapshot creation request based on a snapshot creation instruction of a user.

In this manner 1, the process of the terminal initiating the snapshot creation request depends on the operation of the user.

Mode 2: and the terminal automatically initiates a snapshot creation request in response to meeting the snapshot creation requirement.

In the mode 2, the process of the terminal initiating the snapshot creation request is automatically controlled by the terminal, and does not depend on the operation of the user. The requirement for meeting snapshot creation is set according to experience, or flexibly adjusted according to an actual application scenario, which is not limited in the embodiment of the present application. Illustratively, satisfying the snapshot creation request means that a reference time length is reached from a time interval of last initiating the snapshot creation request; or, satisfying the snapshot creation request means that the data volume written by the terminal to the server reaches the data volume threshold after the snapshot creation request is initiated last time. Both the reference time length and the data amount threshold may be set empirically.

No matter which way the snapshot creation request is initiated, the server obtains the snapshot creation request after the terminal initiates the snapshot creation request. In a possible implementation manner, software or program code for processing the snapshot creation related service is installed in the server, and the software or program code can automatically acquire the snapshot creation request initiated by the terminal.

In one possible implementation, the snapshot creation request includes an identification of at least one target storage unit. The identifier of any target storage unit is used to uniquely identify the any target storage unit, and the embodiment of the present application does not limit the form of the identifier of any target storage unit, and exemplarily, the identifier of any target storage unit refers to a name of any target storage unit, or the identifier of any target storage unit refers to a mount address of any storage unit.

In an exemplary embodiment, the data format of the snapshot creation request is "create _ constest _ snap _ group (lv1, lv2, …, lvN)", where 1, 2, and N represent names of target storage units, and the snapshot creation request of the data format is used to indicate that a data consistency snapshot group is created for a group of target storage units with names 1, 2, and N, and the data consistency snapshot group includes snapshots respectively created for the respective target storage units.

In an exemplary embodiment, for some database services, or RAID services made on a disk basis, the snapshot is created in order to backup some or all of the data that the terminal has uploaded to the server that needs to be stored. In an exemplary embodiment, the server processes the data uploaded by the terminal and needing to be stored in a certain storage unit, including but not limited to the following two ways: 1. caching data needing to be stored in a certain storage unit in a memory by a server, and then synchronizing the data in the memory to the storage unit; 2. the server directly stores the data to be stored in a certain storage unit in the storage unit. The specific processing method can be set by the terminal. At a certain moment, the data which is uploaded to the server by the terminal and needs to be stored in a certain storage unit may be completely stored in the storage unit, or may still be partially stored in the memory.

When the snapshot creation request is acquired, it is stated that the terminal wishes to backup, based on the created snapshot, data that needs to be stored in the at least one target storage unit and that has been uploaded to the server when the snapshot creation request was initiated. In the embodiment of the present application, data that needs to be stored in a certain target storage unit and has been uploaded to a server when a snapshot creation request is initiated is referred to as data that the target storage unit should theoretically store. It should be noted that, when a snapshot creation request is initiated, only part of data in data that should be theoretically stored may be stored in a certain target storage unit, and the rest of the data is still in the memory of the server.

In an exemplary embodiment, for a case that the number of target storage units that need to create a snapshot and are indicated by a snapshot creation request is multiple, data that each target storage unit should theoretically store is all part or all of data that the terminal has uploaded to the server when initiating the snapshot creation request, that is, data that each target storage unit should theoretically store is all data that should theoretically be stored at the same time. Before snapshots are created for the target storage units, it is necessary to ensure that each target storage unit stores and only stores data that each target storage unit should theoretically store, so as to ensure data consistency among the snapshots created for each target storage unit, and to ensure reliability of subsequent data recovery based on the snapshots. Data consistency here means that data in each snapshot is data that should be theoretically stored at the same time.

In an exemplary embodiment, in an actual application scenario, a service of a terminal may perform data writing operation on multiple storage units simultaneously, or a service data disk is a RAID group composed of multiple storage units. In this case, a user needs to create a snapshot for each storage unit of the plurality of storage units and ensure that snapshots of the storage units can achieve real data consistency, that is, data in several snapshots are data that should be theoretically stored by the corresponding storage unit at the same time.

In step 202, based on the snapshot creation request, the global state of the system is set to a write-inhibited state, where the write-inhibited state is used to indicate that data write operations corresponding to all storage units are blocked.

When a snapshot creating request is acquired, it is indicated that a snapshot needs to be created for at least one target storage unit, and at this time, the global state of the system is set to a write-inhibit state to block data write operations corresponding to all storage units. The system herein refers to a system of servers. It should be noted that all storage units may include other storage units besides the at least one target storage unit that needs to create the snapshot and is indicated by the snapshot creation request. Assuming that the acquisition time of the snapshot creation request is T time, the global state of the system is set to the write-prohibited state, so that it can be ensured that all storage units mounted on the server and the server do not include newly-added data to be stored, which is uploaded by the terminal after T time.

In one possible implementation, the data write operation corresponding to any memory cell includes, but is not limited to, two forms: directly storing the data to be stored corresponding to any storage unit into the any storage unit; or, caching the data to be stored corresponding to any storage unit into the memory, and then synchronizing the data to be stored in the memory into any storage unit. Blocking the data write operation corresponding to any memory cell refers to blocking the above two types of data write operations.

In one possible implementation, the global state of the system is controlled by a global parameter, and the implementation of setting the global state of the system to the write-inhibit state is as follows: setting a global parameter for controlling a global state of the system to a target value, the target value indicating that the global state of the system is a write-inhibit state. The target value is set by the developer, for example, the target value is 1. Illustratively, the global parameter is "hang _ all _ device _ io", the target value is 1, and the process of setting the global state of the system to the write-inhibit state is completed by setting "hang _ all _ device _ io" to 1 ".

It should be noted that, after the snapshot creation request is obtained, the global state of the system is set to the write-inhibit state immediately, and the setting of the global state of the system can be implemented only by setting one parameter, that is, the time consumption for setting the global state of the system to the write-inhibit state is extremely short, and in the extremely short time consumption process, it is considered that the terminal has not reached the time to upload the new data to be stored to the server after the snapshot creation request is initiated. That is, in the write-prohibited state, the server and all the mounted storage units still manage data that has been uploaded to the server when the terminal initiated the snapshot creation request.

It should be noted that, when the global state of the system is set to the write-prohibited state, the data that has been uploaded to the server when the terminal initiates the snapshot creation request may have all been synchronized to the corresponding storage unit, or only part of the data may have been synchronized to the corresponding storage unit and the other part of the data still exists in the memory of the server, which is not limited in this embodiment of the present application. After the global state of the system is set to the write-inhibited state, step 203 is performed.

In step 203, a memory data synchronization operation is performed on the at least one target storage unit based on the write-inhibit status.

In an exemplary embodiment, the snapshot creation request includes an identifier of at least one target storage unit, and according to the snapshot creation request, at least one target storage unit may be determined in all the storage units, and further, based on the write-prohibited state, a memory data synchronization operation is performed on the at least one target storage unit.

In one possible implementation, the process of performing the memory data synchronization operation on any target storage unit is as follows: and determining target memory data corresponding to any target storage unit in the data in the memory, and synchronizing the target memory data to any target storage unit. It should be noted that the data in the memory here refers to the data in the memory of the server at the time of executing the memory data synchronization operation on any target storage unit. The data in the memory may include memory data corresponding to one or more storage units, and target memory data corresponding to a target storage unit is synchronized to the target storage unit. It should be noted that the target memory data corresponding to any target storage unit refers to data still in the memory in the data that should be theoretically stored by any target storage unit.

In an exemplary embodiment, the memory data synchronization operation process executed on any target storage unit is realized based on a synchronization command "sync _ cache (lvname)", where "lvname" in the synchronization command is used to indicate a name of any target storage unit.

It should be noted that, in the above-described manner, a manner of performing a memory data synchronization operation on any target storage unit when data in a memory includes target memory data corresponding to the target storage unit is described. In an exemplary embodiment, the data in the memory may not include the target memory data corresponding to any target storage unit, that is, the data that should be theoretically stored in any target storage unit is already stored in any target storage unit, in this case, the memory data synchronization operation performed on any target storage unit is performed by: the data stored in any of the target storage units is kept unchanged.

In one possible implementation, the default state of all storage units is a non-to-be-created snapshot state. Based on the write-inhibit status, the manner of performing the memory data synchronization operation on the at least one target storage unit includes, but is not limited to, the following two ways:

mode A: and under the write-inhibit state, directly executing memory data synchronization operation on at least one target storage unit in a state not to be created.

In this way, the state of the at least one target memory cell does not need to be additionally set, and the operation is simple. It should be noted that, in this manner a, the whole process of performing the memory data synchronization operation on at least one target storage unit in the state not to be created is performed in the write-inhibited state, so as to ensure that, in the process of performing the memory data synchronization operation, no new data other than the data that should be theoretically stored is stored in each target storage unit.

In the process of implementing the memory data synchronization operation based on the mode a, since the data write operation corresponding to all the storage units is always blocked, the newly added memory data related to any storage unit will not be cached in the memory of the server all the time. Based on this, after the target storage unit in the state of not being created is executed with the memory data synchronization operation, it can be ensured that all data which should be theoretically stored by the target storage unit when the terminal initiates the snapshot creation request is stored in the target storage unit.

Mode B: setting the state of at least one target storage unit to be a snapshot state to be created in a writing-inhibited state; and executing memory data synchronization operation on at least one target storage unit to be in the snapshot state.

In the mode B, the snapshot state to be created is used to mark the at least one target storage unit that needs to create the snapshot, and the memory data synchronization operation is performed on the at least one target storage unit that needs to create the snapshot state.

In one possible implementation manner, the process of setting the state of at least one target storage unit to be the snapshot state to be created is performed sequentially, and the states of the respective target storage units are set to be the snapshot state to be created sequentially. It should be noted that, in the process of sequentially setting the states of the target storage units as the to-be-created snapshot states, the global state of the system is always in the write-inhibit state, and based on this way, it can be ensured that no new data is stored in each target storage unit before the state of each target storage unit is set as the to-be-created snapshot state.

In one possible implementation, for any target storage unit in the at least one target storage unit, the state of the any target storage unit is controlled by the state parameter corresponding to the any target storage unit. The implementation manner of setting the state of any target storage unit as the state of the snapshot to be created is as follows: and setting the state parameter corresponding to any target storage unit as a reference value, wherein the reference value is used for indicating that the state of any target storage unit is a snapshot state to be created. The reference value is set by the developer, for example, the reference value is 1. Exemplarily, the state parameter corresponding to the any target storage unit is "lvname.hang _ dev _ flag", where "lvname" is used to indicate a name of the any target storage unit, and if the reference value is 1, the process of setting the state of the any target storage unit to the state of the snapshot to be created is completed by setting "lvname.hang _ dev _ flag" to 1 ".

The to-be-created snapshot state can be used to indicate that any of the target storage units is preparing to create a snapshot. And for each target storage unit in the at least one target storage unit, executing a process of setting the corresponding state parameter as a reference value, so that each target storage unit in the at least one target storage unit is in a snapshot state to be created.

In a possible implementation manner, in response to that the states of at least one target storage unit are all snapshot states to be created, the global state of the system is restored to a non-write-inhibit state, where the non-write-inhibit state is used to indicate that a data write operation corresponding to a storage unit which is not in the snapshot states to be created is restored. That is to say, after it is determined that the states of the target storage units are all set as snapshots to be created, the global state of the system is timely restored to a non-write-inhibit state, so that data write operations corresponding to the storage units in the snapshot state not to be created are timely restored.

It should be noted that it takes a short time to set the state of at least one target memory cell to the to-be-created state, and a time interval between setting the global state of the system to the write-inhibited state and restoring the global state of the system to the non-write-inhibited state is short, and the time interval is, for example, on the order of milliseconds. This way, interference to data write operation of other memory cells can be reduced.

In one possible implementation manner, for the global state of the system controlled by the global parameter, the implementation manner of setting the global state of the system to the write-inhibit state is the case of setting the global parameter to the target value, and the implementation manner of restoring the global state of the system to the non-write-inhibit state is as follows: and restoring the global parameter from the target value to the first default value. The first default value is used to indicate that the global state of the system is a non-write-inhibit state. The first default value is set by the developer, for example, the first default value is 0. Illustratively, the global parameter is "hang _ all _ device _ io", and the first default value is 0, then the process of restoring the global state of the system to the non-write-inhibited state is completed by restoring "hang _ all _ device _ io to 1" to "hang _ all _ device _ io to 0".

In an exemplary embodiment, the complete process of performing the memory data synchronization operation on any target storage unit to be created in the snapshot state may completely occur in the write-inhibited state; it may also occur entirely in the non-write inhibit state; the write-inhibit state may be partially generated, and the non-write-inhibit state may be partially generated.

It should be noted that, since the non-write-inhibit state is used to instruct to restore the data write operation corresponding to the storage unit in the non-to-be-created snapshot state, even in the non-write-inhibit state, the data write operation corresponding to each target storage unit that has been set to the to-be-created snapshot state is still blocked. Under the condition that the data writing operation corresponding to each target storage unit is blocked, the server does not cache the newly added data corresponding to each target storage unit in the memory, and does not directly store the newly added data corresponding to each target storage unit in each target storage unit. That is, even in the non-write-inhibit state, the memory of the server does not cache the newly added memory data of each target storage unit, so that the target storage unit can be ensured to store and only store all data that the target storage unit should theoretically store when the terminal initiates the snapshot creation request after executing the external memory data synchronization operation.

It should be further described that the process of performing the memory data synchronization operation on the at least one target storage unit to be in the to-be-created state may be performed after the states of the at least one target storage unit are all set to be in the to-be-created snapshot state, or may be performed simultaneously with the process of setting the state of the at least one target storage unit to be in the to-be-created snapshot state, which is not limited in this embodiment of the present application.

For example, for a case that the process of performing the memory data synchronization operation on the at least one target storage unit in the to-be-processed state is performed after the state of the at least one target storage unit is set to the to-be-created snapshot state, the process of performing the memory data synchronization operation on the at least one target storage unit in the to-be-processed state may be to sequentially perform the memory data synchronization operation on each target storage unit, or may be to simultaneously perform the memory data synchronization operation on a plurality of target storage units in the same batch, which is not limited in this embodiment of the present application.

For example, in a case that a process of performing a memory data synchronization operation on at least one target storage unit in a to-be-processed state is performed simultaneously with a process of setting a state of the at least one target storage unit to a to-be-created snapshot state, each time the state of one target storage unit is set to the to-be-created snapshot state, that is, a memory data synchronization operation is performed on the one target storage unit in the to-be-created snapshot state.

By executing the memory data synchronization operation on at least one target storage unit, the target memory data corresponding to each target storage unit can be ensured to be synchronized into the target storage unit before the snapshot is created. After the target memory data corresponding to each target storage unit is synchronized into the target storage unit, the data stored in any target storage unit is completely consistent with the data which should be theoretically stored by any target storage unit when the snapshot creation request is initiated. For the target storage unit creating the snapshot under the condition, the data protected by the snapshot can be all the data which are stored in any target storage unit in the data which are uploaded to the server by the terminal when the snapshot creation request is initiated.

In step 204, a snapshot is created for at least one target storage unit that has completed the memory data synchronization operation.

In a possible implementation manner, the sequence of executing the memory data synchronization operation on different target storage units may be different, and after the memory data synchronization operation is executed on any target storage unit, a snapshot may be created for the target storage unit. That is, in response to any target storage unit having executed the "sync _ cache (lvname)" command, a snapshot is created for that target storage unit. Illustratively, the process of creating a snapshot for any target storage unit is implemented based on a "create _ snapshot (lvname)" command.

In one possible implementation, the process of creating a snapshot for any target storage unit is: and calling a snapshot creating interface corresponding to any target storage unit to create a snapshot for any target storage unit in response to any target storage unit finishing executing the memory data synchronization operation. That is, the "create _ snapshot (lvname)" command is implemented by calling the snapshot creation interface corresponding to the target storage unit.

The snapshot creation interface corresponding to any target storage unit refers to an interface provided by a provider of the target storage unit and used for creating a snapshot. It should be noted that different target storage units may correspond to the same snapshot creation interface or may correspond to different snapshot creation interfaces, which is not limited in the embodiment of the present application. In an exemplary embodiment, target storage units provided by the same provider correspond to the same snapshot creation interface, and target storage units provided by different providers correspond to different snapshot creation interfaces.

In an exemplary embodiment, a snapshot creating Interface corresponding to any target storage unit is an Application Programming Interface (API), a function for creating a snapshot is predefined in the API corresponding to any target storage unit, and the creation of a snapshot can be directly realized based on the predefined function by calling the API. In an exemplary embodiment, different providers can customize the function that implements creating snapshots, such that target storage units provided by different providers implement creation of snapshots based on different functions. No matter what kind of function is used for creating the snapshot, the snapshot can be created for each target storage unit which executes the memory data synchronization operation in a mode of calling a snapshot creation interface.

In one possible implementation manner, after creating a snapshot for at least one target storage unit that has performed the memory data synchronization operation, the method further includes: and restoring the state of at least one target storage unit of which the snapshot is created to a state of a snapshot which is not to be created. In an exemplary embodiment, since the sequence of executing the memory data synchronization operation on different target storage units is different, and the sequence of creating the snapshot for different target storage units is also different, based on this, the state of a target storage unit can be restored to the state of the non-to-be-created snapshot every time the snapshot is created for one target storage unit, so that the data write operation corresponding to the target storage unit can be restored in time.

In one possible implementation manner, for a case that the state of any target storage unit is controlled by the state parameter corresponding to the any target storage unit, the implementation manner of setting the state of any target storage unit to the snapshot state to be created is to set the state parameter corresponding to any target storage unit to the reference value, and the implementation manner of restoring the state of any target storage unit to the snapshot state not to be created is: and restoring the state parameter corresponding to any target storage unit from the reference value to a second default value. The second default value is used to indicate that the state of any target storage unit is a non-to-be-created snapshot state. The second default value is set by the developer, for example, the second default value is 0. Illustratively, the state parameter corresponding to any target storage unit is "lvname.hang _ dev _ flag", and the second default value is 0, then the process of restoring the state of any target storage unit to the non-snapshot state to be created is completed by restoring "lvname.hang _ dev _ flag to 1" to "lvname.hang _ dev _ flag to 0".

Illustratively, the process of snapshot creation is shown in FIG. 3. Acquiring a snapshot creation request, wherein the data format of the snapshot creation request is 'create _ constest _ snap _ group (lv1, lv2, …, lvN)'; setting the global state of the system to be a write-prohibited state by setting "hand _ all _ device _ io to 1" based on the snapshot creation request; in a writing prohibition state, setting the state of each target storage unit to be a snapshot state to be created by setting "lvname. And in response to the condition that the at least one target storage unit is the snapshot condition to be created, restoring the global condition of the system to a non-write-inhibit condition by restoring "hang _ all _ device _ io" to "1".

Executing memory data synchronization operation on at least one target storage unit to be created with a snapshot state based on a synchronization command 'sync _ cache (lv1, lv2, …, lvN)'; and respectively calling the snapshot creating interfaces respectively corresponding to the target storage units to create snapshots for the target storage units executing the memory data synchronous operation. The process of creating snapshots for different target storage units is implemented based on different commands, for example, the process of creating snapshots for target storage units named 1 is implemented based on a "create _ snapshot (lv 1)" command, the process of creating snapshots for target storage units named 2 is implemented based on a "create _ snapshot (lv 2)" command, and the process of creating snapshots for target storage units named N is implemented based on a "create _ snapshot (lv)" command.

In one possible implementation manner, the snapshot creation process provided in the embodiment of the present application may be implemented based on software or program code, that is, software or program code for implementing the snapshot creation process is installed or integrated in the server.

In a possible implementation manner, in addition to the snapshot creation request initiated by the obtaining terminal, the server may further obtain a data write request, where the data write request is used to instruct to process a data write operation corresponding to the at least one target storage unit. And the data writing operation corresponding to the at least one target storage unit is used for storing the new data in the at least one target storage unit.

In an exemplary embodiment, the write operation entry "sys _ write" in the system of the server can control the write IO to appropriately process a data write operation corresponding to at least one target storage unit according to an actual global state, a state of the target storage unit, and the like.

In one possible implementation manner, after the data write request is obtained, the server first detects whether the global state of the system is a write-inhibit state. In one possible implementation, the write operation entry "sys _ write" in the system of the server determines whether the global state of the system is a write-inhibit state by detecting whether the value of the global parameter "hand _ all _ device _ io" is 1. If the global state of the system is a write-inhibit state, executing the step A; if the global state of the system is a non-write-inhibit state, executing the step B:

step A: and in response to the global state of the system being a write-inhibit state, blocking data write operation corresponding to at least one target storage unit.

When a write operation entry 'sys _ write' in the system detects that a value of 'hang _ all _ device _ io' is 1, it indicates that the global state of the system is a write-inhibit state, and since the write-inhibit state is used to indicate that data write operations corresponding to all memory cells are blocked, if a data write request is acquired, the global state of the system is the write-inhibit state, and then data write operations corresponding to at least one target memory cell are blocked.

In one possible implementation, blocking the data write operation corresponding to the at least one target storage unit means that the data write operation corresponding to the at least one target storage unit is not to be performed. And C, waiting for the global state of the system to be recovered to a non-write-inhibition state, and executing the step B.

And B: and responding to the fact that the global state is a non-write-inhibition state, blocking data write operation corresponding to the target storage unit in the snapshot state to be created, and executing data write operation corresponding to the target storage unit in the snapshot state not to be created.

When the write operation entry "sys _ write" in the system detects that the value of "hang _ all _ device _ io" is 0, it indicates that the global state of the system is a non-write-inhibit state, and since the non-write-inhibit state is used to indicate to resume a data write operation corresponding to a storage unit that is not in a snapshot state to be created, a processing manner of the data write operation corresponding to at least one target storage unit is related to the state of the at least one target storage unit.

In an exemplary embodiment, the state of the target memory cell is determined by detecting the value of a state parameter "lvname. If the value of a state parameter 'lvname, hand, dev, flag' corresponding to a certain target storage unit is 1, it indicates that the state of the target storage unit is a snapshot state to be created; and if the value of the state parameter 'lvname, hand _ dev _ flag' corresponding to a certain target storage unit is 0, indicating that the state of the target storage unit is a non-to-be-created snapshot state.

And after the state of each target storage unit is determined, blocking the data writing operation corresponding to the target storage unit in the snapshot state to be created, and executing the data writing operation corresponding to the target storage unit in the snapshot state not to be created. It should be noted that, in the embodiment of the present application, the ratio of the number of the target storage unit in the snapshot state to be created to the number of the target storage unit in the non-snapshot state to be created, which is included in the at least one target storage unit, is not limited. In an exemplary embodiment, only the target storage unit of the at least one target storage unit to be created with the snapshot state is included; or only the target storage unit which is not in the snapshot state to be created is included in the at least one target storage unit.

In an exemplary embodiment, for a target storage unit in which a snapshot state is to be created, a data write operation corresponding to the target storage unit is executed after the state of the target storage unit is recovered to a non-snapshot state to be created.

Exemplarily, the processing procedure after acquiring the data write request is as shown in fig. 4. The write operation entry "sys _ write" in the system determines whether the value of "hang _ all _ device _ io" is 1. And if the value of the "hang _ all _ device _ io" is 1, blocking the data write operation corresponding to at least one target storage unit. And if the value of the "hang _ all _ device _ io" is not 1, judging whether the value of the "lvname.hang _ dev _ flag" of the target storage unit is 1, and if the value of the "lvname.hang _ dev _ flag" of the target storage unit is 1, blocking the data writing operation corresponding to the target storage unit. And if the 'lvname, hand _ dev _ flag' value of the target storage unit is not 1, executing data writing operation corresponding to the target storage unit.

The snapshot creating method provided by the embodiment of the application can realize the complete consistency of the data state of at least one target storage unit when creating the snapshot, and ensure that the data consistency snapshot is created for at least one target storage unit in the same server. That is, the snapshot protected data created by the at least one target storage unit are all data that should be theoretically stored at the same time (at the time of initiating the snapshot creation request), so that data consistency and data security are ensured. In addition, the creation of the snapshot is realized by calling a snapshot creation interface, so that the process of creating the data consistency snapshot by the storage units provided by different providers can be realized.

Referring to fig. 5, an embodiment of the present application provides a snapshot creating apparatus, including:

an obtaining module 501, configured to obtain a snapshot creating request, where the snapshot creating request is used to instruct to create a snapshot for at least one target storage unit;

a setting module 502, configured to set a global state of the system to a write-inhibit state based on the snapshot creation request, where the write-inhibit state is used to indicate that data write operations corresponding to all storage units are blocked;

an operation executing module 503, configured to execute a memory data synchronization operation on at least one target storage unit based on the write-inhibit status;

a creating module 504, configured to create a snapshot for at least one target storage unit that has completed the memory data synchronization operation.

In a possible implementation manner, the setting module 502 is further configured to set the state of the at least one target storage unit to the state of the snapshot to be created in the write-inhibited state.

The operation executing module 503 is configured to execute a memory data synchronization operation on at least one target storage unit to be created in the snapshot state.

In a possible implementation manner, the setting module 502 is further configured to, in response to that the states of the at least one target storage unit are all snapshot states to be created, restore the global state of the system to a non-write-inhibit state, where the non-write-inhibit state is used to indicate that a data write operation corresponding to a storage unit that restores the snapshot states not to be created is resumed.

In a possible implementation manner, the setting module 502 is further configured to restore the state of the at least one target storage unit that has created the snapshot to a state that is not the snapshot to be created.

In a possible implementation manner, the creating module 504 is configured to, in response to that any target storage unit completes executing the memory data synchronization operation, call a snapshot creating interface corresponding to any target storage unit to create a snapshot for any target storage unit.

In one possible implementation manner, the operation executing module 503 is configured to determine, from data in the memory, target memory data corresponding to any target storage unit, and synchronize the target memory data to any target storage unit.

In a possible implementation manner, the obtaining module 501 is further configured to obtain a data write request, where the data write request is used to instruct to process a data write operation corresponding to at least one target storage unit;

the operation executing module 503 is further configured to block a data write operation corresponding to at least one target storage unit in response to that the global state of the system is a write-inhibit state.

the operation executing module 503 is further configured to block a data write operation corresponding to a target storage unit in the to-be-created snapshot state and execute a data write operation corresponding to a target storage unit in the to-be-created snapshot state in response to that the global state of the system is the non-write-prohibited state.

It should be noted that, when the apparatus provided in the foregoing embodiment implements the functions thereof, only the division of the functional modules is illustrated, and in practical applications, the functions may be distributed by different functional modules according to needs, that is, the internal structure of the apparatus may be divided into different functional modules to implement all or part of the functions described above. In addition, the apparatus and method embodiments provided by the above embodiments belong to the same concept, and specific implementation processes thereof are described in the method embodiments for details, which are not described herein again.

Fig. 6 is a schematic structural diagram of a server according to an embodiment of the present application, where the server may generate a relatively large difference due to different configurations or performances, and may include one or more processors (CPUs) 601 and one or more memories 602, where at least one program code is stored in the one or more memories 602, and is loaded and executed by the one or more processors 601 to implement the snapshot creation method according to the above-described method embodiments. Of course, the server may also have components such as a wired or wireless network interface, a keyboard, and an input/output interface, so as to perform input/output, and the server may also include other components for implementing the functions of the device, which are not described herein again.

In an exemplary embodiment, a computer device is also provided that includes a processor and a memory having at least one program code stored therein. The at least one program code is loaded into and executed by one or more processors to implement any of the snapshot creation methods described above.

In an exemplary embodiment, there is also provided a computer-readable storage medium having at least one program code stored therein, the at least one program code being loaded and executed by a processor of a computer device to implement any of the snapshot creation methods described above.

In one possible implementation, the computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc Read-Only Memory (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, and the like.

In an exemplary embodiment, a computer program product or computer program is also provided, the computer program product or computer program comprising computer instructions stored in a computer readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to cause the computer device to perform any one of the snapshot creation methods described above.

It should be understood that reference to "a plurality" herein means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

The above description is only exemplary of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A snapshot creation method, the method comprising:

2. The method of claim 1, wherein performing a memory data synchronization operation on the at least one target storage unit based on the write-inhibit status comprises:

setting the state of the at least one target storage unit to be a snapshot state to be created in the write-inhibit state;

and executing memory data synchronization operation on the at least one target storage unit in the snapshot state to be created.

3. The method of claim 2, wherein after the setting the state of the at least one target storage unit to the to-be-created-snapshot state in the write-inhibit state, the method further comprises:

and in response to that the states of the at least one target storage unit are the to-be-created snapshot states, restoring the global state of the system to a non-write-inhibit state, wherein the non-write-inhibit state is used for indicating data write operation corresponding to the storage unit for restoring the non-to-be-created snapshot state.

4. The method of claim 3, wherein after creating the snapshot for the at least one target storage unit that has performed the memory data synchronization operation, the method further comprises:

and restoring the state of at least one target storage unit after the snapshot is created into the state of the snapshot not to be created.

5. The method according to any of claims 1-4, wherein said creating a snapshot for at least one target storage unit that has performed the memory data synchronization operation comprises:

and in response to any target storage unit finishing executing the memory data synchronization operation, calling a snapshot creating interface corresponding to the any target storage unit to create a snapshot for the any target storage unit.

6. The method according to any one of claims 1-4, further comprising:

acquiring a data writing request, wherein the data writing request is used for indicating to process data writing operation corresponding to the at least one target storage unit;

and in response to the global state of the system being the write-inhibit state, blocking data write operations corresponding to the at least one target storage unit.

7. The method of claim 4, further comprising:

and in response to that the global state of the system is the non-write-inhibit state, blocking the data write operation corresponding to the target storage unit in the snapshot state to be created, and executing the data write operation corresponding to the target storage unit in the snapshot state not to be created.

8. A snapshot creation apparatus, the apparatus comprising:

9. A computer device comprising a processor and a memory, the memory having stored therein at least one program code, the at least one program code being loaded and executed by the processor to implement a snapshot creation method as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium having stored therein at least one program code, the at least one program code being loaded and executed by a processor to implement the snapshot creation method of any one of claims 1 to 7.