Method and device for processing content file in content delivery network

Abstract

Embodiments of the present disclosure provide a method and device for processing a content file in a content delivery network (CDN). The method comprises: saving metadata information of content files in a node of a CDN to a database; after the capacity of the node is expanded, generating a target hash distribution of the content files in the capacity-expanded node, on the basis of the metadata information and the target hash distribution, migrating a content file which does not conform to the target hash distribution, and updating the metadata information until the content file conforms to the target hash distribution.

Description

Method and device for processing content files in content distribution network

[0001] Cross-references to related publications

[0002] This disclosure is based on Chinese patent application No. 2023108097305, filed on June 30, 2023, entitled “Method and Device for Processing Content Files in a Content Distribution Network”, and claims the priority of the patent disclosure, and all the contents disclosed therein are incorporated into this disclosure by reference. Technical Field

[0003] The present disclosure relates to the field of communications, and in particular to a method and apparatus for processing content files in a content distribution network. Background Art

[0004] Current Content Delivery Network (CDN) system architectures generally divide nodes into edge nodes and central nodes. Edge nodes are responsible for caching popular content viewed by users, while central nodes are responsible for persistently storing popular or specific content on the internet. Content distribution is the process of injecting external content files into the storage of central nodes, regional centers, or edge nodes. Caching content to edge nodes based on content distribution strategies shortens the distance between service points and users. This localized service reduces the difficulty of addressing Quality of Service (QoS) issues and conserves backbone network bandwidth. To ensure service quality, central nodes or regional centers typically need to store massive amounts of content files, and edge nodes also have a large number of cached files for popular content. This places high demands on the CDN's storage capacity. As the number of stored content files continues to increase, the remaining storage space of the entire node will continue to decrease, posing a significant challenge to the stability of the entire system. Nodes often need to address insufficient storage space through horizontal or vertical expansion. However, expanded nodes inevitably suffer from storage imbalances, which can easily lead to problems such as hotspot aggregation, resulting in a poor user experience and uneven system load.

[0005] Summary of the Invention

[0006] The embodiments of the present disclosure provide a method and apparatus for processing content files in a content distribution network, which at least solves the problem that after the nodes of the content distribution network are expanded, the nodes cannot operate normally because the content files do not conform to the hash distribution.

[0007] According to one embodiment of the present disclosure, a method for processing content files in a content distribution network is provided, comprising: saving metadata information of content files of a node of a content distribution network (CDN) to a database; after the node is expanded, generating a target hash distribution of the content files in the expanded node, migrating content files that do not conform to the target hash distribution based on the metadata information and the target hash distribution, and updating the metadata information until the content files conform to the target hash distribution.

[0008] According to another embodiment of the present disclosure, a device for processing content files in a content distribution network is provided, including: a storage module, configured to save metadata information of content files of a node of a content distribution network CDN to a database; a migration module, configured to generate a target hash distribution of the content files in the expanded node after the node is expanded, migrate content files that do not conform to the target hash distribution according to the metadata information and the target hash distribution, and update the metadata information until the content files conform to the target hash distribution.

[0009] According to another embodiment of the present disclosure, a computer-readable storage medium is provided, in which a computer program is stored. The computer program is configured to execute the steps of any one of the above method embodiments when running.

[0010] According to another embodiment of the present disclosure, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the steps in any one of the above method embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 1 is a hardware structure block diagram of a computer terminal according to a method for processing content files in a content distribution network according to an embodiment of the present application;

[0012] 2 is a flowchart of a method for processing content files in a content distribution network according to an embodiment of the present disclosure;

[0013] 3 is a structural block diagram of an apparatus for processing content files in a content distribution network according to an embodiment of the present disclosure;

[0014] 4 is a structural block diagram of an apparatus for processing content files in a content distribution network according to yet another embodiment of the present disclosure;

[0015] 5 is a structural block diagram of an apparatus for processing content files in a content distribution network according to another embodiment of the present disclosure;

[0016] 6 is a structural block diagram of an apparatus for processing content files in a content distribution network according to yet another embodiment of the present disclosure;

[0017] FIG7 is a schematic diagram of a central node according to an embodiment of the present disclosure;

[0018] FIG8 is a flowchart of a method for processing content files in a content distribution network according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and in conjunction with embodiments.

[0020] It should be noted that the terms "first", "second", etc. in the description and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0021] The following is a description of relevant terms in the embodiments of the present disclosure:

[0022] Content Delivery Network: A Content Delivery Network (CDN) is a distributed network consisting of multiple servers and data centers. Its purpose is to improve availability and performance by distributing services geographically close to users. A CDN can cache static content (such as images, videos, and files) and deliver dynamic content (such as live broadcasts and real-time data). This can speed up loading times for websites, mobile apps, and streaming media, improving user satisfaction.

[0023] Hash algorithm: A hash algorithm (hash) is a mathematical function that converts any input data into a fixed-length output, called a hash or hash value. Hash algorithms are one-way, meaning that the original data cannot be restored from the hash value.

[0024] High-performance database: A high-performance database (DB) is a database management system that can perform high-performance data query and management, quickly process large amounts of data and complex queries, and provide efficient information services.

[0025] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a computer terminal as an example, Figure 1 is a hardware structure block diagram of a computer terminal of a method for processing content files in a content distribution network according to an embodiment of the present disclosure. As shown in Figure 1, the computer terminal may include one or more (only one is shown in Figure 1) processors 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 configured to store data, wherein the above-mentioned computer terminal may also include a transmission device 106 and an input and output device 108 configured to have a communication function. It can be understood by those skilled in the art that the structure shown in Figure 1 is only for illustration and does not limit the structure of the above-mentioned computer terminal. For example, the computer terminal may also include more or fewer components than those shown in Figure 1, or have a configuration different from that shown in Figure 1.

[0026] The memory 104 can be configured to store computer programs, such as software programs and modules of application software, such as the computer program corresponding to the method for processing content files in a content distribution network in the embodiments of the present disclosure. The processor 102 executes the computer program stored in the memory 104 to execute various functional applications and data processing, thereby implementing the above-mentioned method. The memory 104 may include a high-speed random access memory and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely located relative to the processor 102, and these remote memories may be connected to the computer terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0027] The transmission device 106 is configured to receive or transmit data via a network. A specific example of the aforementioned network may include a wireless network provided by a computer terminal's communications provider. In one embodiment, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, the transmission device 106 may be a radio frequency (RF) module configured to communicate with the Internet wirelessly.

[0028] In this embodiment, a method for processing content files in a content distribution network running on the above-mentioned computer terminal is provided. FIG2 is a flow chart of the method for processing content files in a content distribution network according to an embodiment of the present disclosure. As shown in FIG2 , the flow chart includes the following steps:

[0029] Step S202, saving metadata information of content files of nodes of the content delivery network CDN to a database;

[0030] Among them, the content distribution network is a distributed storage network composed of multiple servers, providing network acceleration services for users.

[0031] The database may be a high-performance database, which is a database management system that can quickly process large amounts of data and complex queries and provide efficient information services.

[0032] In step S202, the metadata information of the content file of the node of the CDN is saved to the database, including: saving the metadata information of the content file of the node of the CDN to the database of the scheduling management node of the node; wherein the metadata information includes: the provider, name, type, storage device information, size and creation time of the content file.

[0033] By saving various metadata information of content files, we prepare for the subsequent generation of target hash distribution and migration of content files.

[0034] Step S204: After the node is expanded, a target hash distribution of the content files in the expanded node is generated, content files that do not conform to the target hash distribution are migrated according to the metadata information and the target hash distribution, and the metadata information is updated until the content files conform to the target hash distribution.

[0035] Before generating the target hash distribution of the content file in the expanded node in step 204, the method further includes: the scheduling management device of the expanded node receives a request for the content file and description information of the content file; and the scheduling management device locates the storage device of the content file by querying the metadata information according to the description information.

[0036] In step 204, the content files that do not conform to the target hash distribution are migrated according to the metadata information and the target hash distribution, and the metadata information is updated until the content files conform to the target hash distribution. The method also includes: the scheduling management device of the expanded node receives a request for the content file and the description information of the content file; the scheduling management device locates the storage device of the content file through a hash algorithm based on the description information.

[0037] By mapping a key value (content file related information) to one of multiple storage service devices according to a hash algorithm, the storage location of the content file is located.

[0038] In step S204, the target hash distribution of the content file in the expanded node is generated, including: generating the target hash distribution of the content file in the expanded node according to the metadata information and the storage or bandwidth weight information of the device of the expanded node.

[0039] In step S204, content files that do not conform to the target hash distribution are migrated according to the metadata information and the target hash distribution, including: determining the target storage device of the content file according to the metadata information and the target hash distribution; judging whether the target storage device of the content file is the same as the original storage device of the content file; if the target storage device is not the same as the original storage device, migrating the content file to the target storage device.

[0040] In step S204, the node is expanded, which includes one of the following: the number of storage devices of the node is increased; the storage space of all or part of the storage devices of the node is increased.

[0041] In an exemplary embodiment, migrating the content file to the target storage device includes: the target storage device sending a request to receive the content file to the provider of the content file or the upper-level source station according to an instruction to receive the content file, and receiving the content file; and the original storage device deleting the content file.

[0042] Through the embodiments of the present disclosure, since the metadata information of the content files of the content distribution network is saved before expansion, after expansion, in order to ensure that the nodes can still operate normally, the target hash distribution of the content files in the expanded nodes is first generated, and based on the metadata information and the target hash distribution, the content files that do not conform to the target hash distribution are migrated until all the content files conform to the hash distribution and the nodes can operate normally. Therefore, the problem that after the nodes of the content distribution network are expanded, the nodes cannot operate normally because the content files do not conform to the hash distribution can be solved, thereby achieving the effect of ensuring the reliability of the nodes after expansion.

[0043] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus the necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the embodiment of the present disclosure is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD-ROM), including a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present disclosure.

[0044] This embodiment also provides a device for processing content files in a content distribution network. The device is configured to implement the above-mentioned embodiments and preferred implementations, and details already described will not be repeated. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0045] FIG3 is a structural block diagram of a device for processing content files in a content distribution network according to an embodiment of the present disclosure. As shown in FIG3 , the device includes a storage module 10 and a migration module 20 .

[0046] A storage module 10 is configured to store metadata information of content files of a node of a content delivery network CDN into a database;

[0047] The migration module 20 is configured to generate a target hash distribution of the content files in the expanded node after the node is expanded, migrate the content files that do not conform to the target hash distribution according to the metadata information and the target hash distribution, and update the metadata information until the content files conform to the target hash distribution.

[0048] FIG4 is a structural block diagram of an apparatus for processing content files in a content distribution network according to yet another embodiment of the present disclosure. As shown in FIG4 , in addition to all the modules shown in FIG3 , the migration module 20 further includes:

[0049] A receiving unit 21, configured as a scheduling management device of the expanded node to receive a request for the content file and description information of the content file;

[0050] The positioning unit 22 is configured so that the scheduling management device can locate the storage device of the content file by querying the metadata information according to the description information.

[0051] FIG5 is a structural block diagram of an apparatus for processing content files in a content distribution network according to another embodiment of the present disclosure. As shown in FIG5 , in addition to all the modules shown in FIG3 , the apparatus further includes: a receiving module 30 and a positioning module 40 .

[0052] A receiving module 30, configured as a scheduling management device of the expanded node to receive a request for the content file and description information of the content file;

[0053] The positioning module 40 is configured to allow the scheduling management device to locate the storage device of the content file through a hash algorithm according to the description information.

[0054] FIG6 is a structural block diagram of an apparatus for processing content files in a content distribution network according to another embodiment of the present disclosure. As shown in FIG6 , in addition to all the modules shown in FIG3 , the migration module further includes: a generation unit 23 .

[0055] The generating unit 23 is configured to generate the target hash distribution of the content file in the expanded node according to the metadata information and the storage or bandwidth weight information of the device of the expanded node.

[0056] It should be noted that the above modules can be implemented through software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all located in the same processor; or the above modules are located in different processors in any combination.

[0057] To facilitate understanding of the technical solutions provided by the embodiments of the present disclosure, the embodiments will be described in detail below in conjunction with specific scenarios.

[0058] FIG7 is a schematic diagram of a central node according to an embodiment of the present disclosure. As shown in FIG7 , the central node includes: one or more scheduling management devices, and one or more content storage service devices;

[0059] The scheduling management device manages the subordinate storage service devices, and the scheduling management device and the content storage service device can be installed together or separately. The scheduling management device needs to use a high-performance memory database module in the embodiment of the present disclosure. The database module has no special requirements for the technology selection. In the embodiment of the present disclosure, the scheduling management device needs to switch between hash mode and DB mode, using a hash algorithm and a high-performance database for content file distribution and positioning, respectively, to improve service stability and reliability when the content hash distribution state is destroyed after node expansion.

[0060] The storage service device is configured to store content files injected by content providers into the central node. Content files can be media files, image files, and other files. File injection tasks are dispatched to each storage service device via the scheduling management device, and the injected files are saved to the file system.

[0061] The scheduling management equipment should regularly collect information from subordinate storage service equipment to ensure real-time control of the storage space of subordinate nodes.

[0062] For edge cache service nodes, the architecture is similar to that of content center nodes. The difference is that they store content cached from the source, rather than content injected by content providers.

[0063] FIG8 is a flow chart of a method for processing content files in a content distribution network according to yet another embodiment of the present disclosure. Taking a central node as an example, the flow chart illustrates how to process content files of the central node to achieve a smooth transition before and after the central node is expanded. As shown in FIG8 , the specific process is as follows:

[0064] Step S802, when the node is in hash mode, records content metadata;

[0065] Specifically, under normal conditions, the scheduling management device of the central node is in hash mode. At this time, when a user requests a content file, a storage service device in the central node will be calculated through a hash algorithm based on the file description information of the file, and the user will be redirected to the device, where the user will receive content file services.

[0066] Step S804: If the storage space is insufficient or the storage is unbalanced, perform horizontal expansion or vertical expansion;

[0067] Specifically, content providers continuously inject content files, which can lead to storage imbalances or insufficient storage space at the central node. Because the files injected by content providers require persistent storage and cannot be lost, horizontal or vertical expansion is typically performed. Horizontal expansion involves increasing the number of storage services devices at the central node to increase total storage space; vertical expansion involves increasing the storage space of all or some of the devices at the central node, also achieving the goal of increasing total storage space.

[0068] Specifically, after the expansion action occurs, the original hash distribution relationship of the entire central node is destroyed. Therefore, when the hash algorithm is used to locate the content requested by the user, a positioning error problem will occur. The conventional solution is to save a set of old hash weight information, and use the weight information before the expansion to perform hash calculations when scheduling user services, and use the cutover tool to adjust the distribution of the content of the entire central node. During this process, the expansion operation cannot be performed again. Therefore, the embodiment of the present disclosure proposes a method for using a high-performance database to store metadata in advance, and saves the metadata of all content files injected into this node, but uses a hash algorithm to select equipment during service scheduling to ensure high performance and low latency of scheduling.

[0069] Step S806: Switch to DB mode and locate through metadata;

[0070] Specifically, the node is switched to the DB mode in the embodiment of the present disclosure for operation. The so-called DB mode means that the metadata information of the content is stored and managed regardless of whether it is injected or returned to the source to generate cache. Since the previous hash distribution has been destroyed by the expansion action, the current content distribution relationship can no longer be calculated by the hash algorithm, so it is necessary to determine the device where the file is stored by querying the metadata. When using the DB mode for positioning services, first perform a metadata query on the content requested by the user. If the metadata information can be queried, the user can be directly redirected to the corresponding node service stored in the metadata; if the metadata information cannot be queried, a device is calculated according to the hash algorithm to dispatch the user. At this time, the entire service process has an additional memory database query process, so compared with the hash algorithm, its scheduling delay will increase, especially in high-concurrency scenarios, but it also ensures the accuracy and stability of content positioning scheduling at this time.

[0071] Step S808: Node content is automatically balanced;

[0072] Specifically, after switching to DB mode, the node starts a background task to recalculate the hash distribution based on the metadata of the content and the storage or bandwidth weight information of the current device. If the calculation result is inconsistent with the metadata description, a migration task needs to be generated to migrate the content from the original device to the new device and update the metadata storage. The so-called migration task, for the central node and the edge media service node, is a content injection task and a cache injection task respectively. The implementation method is to send a remote procedure call (RPC) instruction to the node device through the application layer protocol. The node device requests the content provider or the upper source station to obtain the specified content file and store it in the current device according to the instruction content. After completing the download or returning to the source, it is necessary to synchronously generate the content deletion / cache deletion RPC instruction to the source data node to delete the original content and metadata to ensure data uniqueness.

[0073] Step S810, determining whether the node has reached a hash distribution steady state;

[0074] Specifically, metadata is scanned to determine whether the node has reached a steady state in hash distribution. If the devices recorded in the metadata scanned by the background task are consistent with the devices calculated by the current weight information, the node is considered to have recovered to a steady state and the process jumps to step S812. If there are still content with a hash distribution mismatch, migration tasks need to be generated again, and the process jumps to step S808 until the entire node is restored to a stable state. Throughout this process, task generation also needs to be throttled to avoid affecting the node's running services.

[0075] Step S812: Switch to using a hash algorithm to locate the content device.

[0076] Specifically, once the node returns to a steady state, it switches back to the hash algorithm for user service scheduling. Throughout the automatic content balancing process, user service scheduling is performed using metadata stored in the database. While this increases latency compared to using the hash algorithm, it significantly improves the reliability of the entire balancing process and resolves the issue of being unable to scale up again during the previous balancing process.

[0077] An embodiment of the present disclosure further provides a computer-readable storage medium, in which a computer program is stored. The computer program is configured to execute the steps of any one of the above method embodiments when run.

[0078] In an exemplary embodiment, the computer-readable storage medium may include, but is not limited to, various media that can store computer programs, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disk.

[0079] An embodiment of the present disclosure further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0080] In an exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0081] For specific examples in this embodiment, reference may be made to the examples described in the above embodiments and exemplary implementation modes, and this embodiment will not be described in detail here.

[0082] By using a hash algorithm plus a high-performance database model, the service and management processes are separated. The content metadata is stored in a high-performance memory database to achieve accurate content positioning when the hash distribution relationship is destroyed after the entire node is expanded, effectively ensuring the reliability of the service during the expansion process. At the same time, by scanning the content metadata of the entire node, migration tasks are generated for content that does not conform to the hash distribution after expansion, and the content is migrated to the home device to achieve automatic content balancing among servers within the same node. After the entire central node reaches a steady state, it switches back to the service mode that uses the hash algorithm to locate content to achieve a smooth transition and improve the user experience during the entire expansion process.

[0083] Obviously, those skilled in the art should understand that the various modules or steps of the above-mentioned embodiments of the present disclosure can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented using program codes executable by the computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be performed in a different order than herein, or they can be made into individual integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module for implementation. Thus, the present disclosure is not limited to any specific combination of hardware and software.

[0084] The above description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will appreciate that various modifications and variations of the present disclosure are possible. Any modifications, equivalent substitutions, or improvements made within the principles of the present disclosure are intended to be within the scope of protection of the present disclosure.

Claims

1. A method for processing content files in a content distribution network, comprising: Saving metadata information of content files of nodes of content delivery network CDN to a database; After the node is expanded, a target hash distribution of the content files in the expanded node is generated, content files that do not conform to the target hash distribution are migrated according to the metadata information and the target hash distribution, and the metadata information is updated until the content files conform to the target hash distribution.

2. The method according to claim 1, wherein: Before generating the target hash distribution of the content file in the expanded node, the method further includes: The scheduling management device of the expanded node receives a request for the content file and description information of the content file; The scheduling management device locates the storage device of the content file by querying the metadata information according to the description information.

3. The method according to claim 1, wherein: Migrating the content files that do not conform to the target hash distribution according to the metadata information and the target hash distribution, and updating the metadata information until the content files conform to the target hash distribution, further comprising: The scheduling management device of the expanded node receives a request for the content file and description information of the content file; The scheduling management device locates the storage device of the content file through a hash algorithm according to the description information.

4. The method according to claim 1, wherein: Generating the target hash distribution of the content file in the expanded node includes: The target hash distribution of the content file in the expanded node is generated according to the metadata information and the storage or bandwidth weight information of the device of the expanded node.

5. The method according to claim 1, wherein: Migrating content files that do not conform to the target hash distribution according to the metadata information and the target hash distribution includes: Determining a target storage device for the content file according to the metadata information and the target hash distribution; It is determined whether the target storage device of the content file is the same as the original storage device of the content file. If the target storage device is not the same as the original storage device, the content file is migrated to the target storage device.

6. The method according to claim 5, wherein: Migrating the content file to the target storage device includes: The target storage device sends a request to receive the content file to a provider of the content file or a superior source station according to an instruction to receive the content file, and receives the content file; The original storage device deletes the content file.

7. The method according to claim 1, wherein: Saving the metadata information of the content file of the node of the CDN to the database includes: Saving the metadata information of the content file of the node of the CDN to the database of the scheduling management node of the node; The metadata information includes: the provider, name, type, storage device information, size and creation time of the content file.

8. The method according to claim 1, wherein: The node is expanded, including one of the following: The number of storage devices of the node increases; The storage space of all or part of the storage devices of the node is increased.

9. A device for processing content files in a content distribution network, comprising: A saving module, configured to save metadata information of content files of nodes of a content delivery network CDN to a database; The migration module is configured to generate a target hash distribution of the content files in the expanded node after the node is expanded, migrate the content files that do not conform to the target hash distribution according to the metadata information and the target hash distribution, and update the metadata information until the content files conform to the target hash distribution.

10. The device according to claim 9, wherein: The migration module also includes: A receiving unit, configured as a scheduling management device of the expanded node to receive a request for the content file and description information of the content file; The positioning unit is configured so that the scheduling management device can locate the storage device of the content file by querying the metadata information according to the description information.

11. The device according to claim 9, wherein: The device also includes: A receiving module, configured as a scheduling management device of the expanded node to receive a request for the content file and description information of the content file; The positioning module is configured so that the scheduling management device can locate the storage device of the content file through a hash algorithm according to the description information.

12. The device according to claim 9, wherein: The migration module also includes: The generating unit is configured to generate the target hash distribution of the content file in the expanded node according to the metadata information and the storage or bandwidth weight information of the device of the expanded node.

13. A computer-readable storage medium having a computer program stored therein, wherein: When the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 8 are implemented.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method described in any one of claims 1 to 8 are implemented.

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