Data transmission method and apparatus used in virtual switch technology

Abstract

A data transmission method and an apparatus used in a virtual switch technology are provided, and the method includes: receiving an IO request of a virtual machine VM for accessing a file or a disk, and When the IO request is to be sent to a physical NIC by using a user mode Open vSwitch (OVS), converting the IO request into an Internet Small Computer Systems Interface (iSCSI) command in a user mode, and then sending the iSCSI command to the user mode OVS, where the user mode OVS sends the iSCSI command to the physical NIC.

Claims

1. A data transmission method, comprising: receiving, by a hypervisor in a user mode, an input/output (TO) request sent by a virtual machine (VM); determining, by the hypervisor in the user mode, disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located; determining, by the hypervisor in the user mode according to the disk information, that the disk to be accessed by the IO request is a disk of a remote terminal; in response to determining that the disk to be accessed by the IO request is the disk of the remote terminal, determining, by the hypervisor in the user mode, that the IO request is to be sent to a physical network interface controller (NIC) by using a user mode Open vSwitch (OVS), and converting, by the hypervisor in the user mode, the IO request into an Internet Small Computer Systems Interface (iSCSI) command; and sending, by the hypervisor in the user mode, the iSCSI command to the user mode OVS, which sends the iSCSI command to the physical NIC.

2. The data transmission method according to claim 1, wherein the converting of the IO request into the iSCSI command comprises: converting the IO request into a Small Computer System Interface (SCSI) command; and adding an Internet Small Computer Systems Interface (iSCSI) header to the SCSI command to obtain the iSCSI command.

3. A data transmission method, comprising: receiving, by a hypervisor in a user mode, an Internet Small Computer Systems Interface (iSCSI) packet returned by a physical network interface controller (NIC) in response to an input/output (IO) request, wherein the iSCSI packet is to be sent, by using a user mode Open vSwitch (OVS), to a virtual machine that initiates the IO request, and wherein the user mode OVS provides network interworking between virtual machines on a same host or virtual machines on different hosts, wherein the physical NIC receives the IO request that has been converted into a iSCSI command by the hypervisor in the user mode, wherein the hypervisor in the user mode converting the IO request into the iSCSI command further comprises determining disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located, determining that the disk to be accessed by the IO request is a disk of a remote terminal, and determining that the IO request is to be sent to the physical NIC by using the user mode OVS; converting, by the hypervisor in the user mode, the iSCSI packet into an IO response; and sending, by the hypervisor in the user mode, the IO response to the virtual machine that initiates the IO request.

4. The data transmission method according to claim 3, wherein the converting of the iSCSI packet into the IO response comprises: converting the iSCSI packet into an SCSI response; and converting the SCSI response into the IO response.

5. A non-transitory computer storage medium, configured to store instructions, which, when executed by a processor that runs a hypervisor in a user mode, cause the hypervisor in the user mode to perform operations comprising: receiving an input/output (IO) request sent by a virtual machine (VM); determining disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located; determining, according to the disk information, that the disk to be accessed by the IO request is a disk of a remote terminal; in response to determining that the disk to be accessed by the IO request is the disk of the remote terminal, determining that the IO request is to be sent to a physical network interface controller (NIC) by using a user mode Open vSwitch (OVS), and converting the IO request into an Internet Small Computer Systems Interface (iSCSI) command and; sending the iSCSI command to the user mode OVS, which sends the iSCSI command to the physical NIC.

6. The non-transitory computer storage medium according to claim 5, wherein the converting of the IO request into the iSCSI command further comprises: converting, by the hypervisor in the user mode, the IO request into a Small Computer System Interface (SCSI) command; and adding an Internet Small Computer Systems Interface (iSCSI) header to the SCSI command to obtain the iSCSI command.

7. A non-transitory computer storage medium, configured to store instructions, which, when executed by a processor that runs a hypervisor in a user mode, cause the hypervisor in the user mode to perform operations comprising: receiving an Internet Small Computer Systems Interface (iSCSI) packet returned by a physical network interface controller (NIC) in response to an input/output (IO) request, wherein the iSCSI packet is to be sent, by using a user mode Open vSwitch (OVS), to a virtual machine that initiates the IO request, and the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts, wherein the physical NIC receives the IO request that has been converted into a iSCSI command by the hypervisor in the user mode, wherein the hypervisor in the user mode converting the IO request into the iSCSI command further comprises determining disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located, determining that the disk to be accessed by the IO request is a disk of a remote terminal, and determining that the IO request is to be sent to the physical NIC by using the user mode OVS; and converting the iSCSI packet into an IO response in a user mode, and then sending the IO response to the virtual machine that initiates the IO request.

8. The non-transitory computer storage medium according to claim 7, wherein the converting of the iSCSI packet into the IO response further comprises: converting the iSCSI packet into an SCSI response; converting the SCSI response into the IO response.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of a path for processing an IO request by a virtual machine in an existing user mode OVS solution;

(2) FIG. 2 is a schematic structural diagram of a system for implementing a server virtualization scenario used in an embodiment of the present invention;

(3) FIG. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present invention;

(4) FIG. 4 is a schematic structural diagram of another electronic device according to an embodiment of the present invention;

(5) FIG. 5 is a schematic structural diagram of another electronic device according to an embodiment of the present invention;

(6) FIG. 6 is a schematic structural diagram of another electronic device according to an embodiment of the present invention;

(7) FIG. 7 is a flowchart of a data transmission method used in a virtual switch technology according to an embodiment of the present invention;

(8) FIG. 8 is a schematic flowchart of a data transmission method used in a virtual switch technology according to an embodiment of the present invention;

(9) FIG. 9 is a schematic flowchart of another data transmission method used in a virtual switch technology according to an embodiment of the present invention; and

(10) FIG. 10 is a schematic diagram of a path for processing an IO request by a virtual machine according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

(11) To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are a part rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

(12) In an existing user mode OVS solution, performance of a virtual machine for processing an IO request is relatively low. Main reasons for this problem include: A: After the IO request is sent from a virtual disk service process (tapdisk2), context switching is performed twice (that is, the IO request is switched from a user mode to a kernel mode, and then switched from the kernel mode to the user mode); B: In a process of forwarding the IO request, a packet splitting operation is required from a storage stack to a user mode OVS; and C: When the virtual machine processes the IO request by using a procedure shown in FIG. 1, quality of service (Quality of Service, QoS) control is performed twice. QoS control is performed in the storage stack, and the user mode OVS also has a QoS control capability. Consequently, the performance of the virtual machine for processing the IO request is affected to some extent.

(13) Based on the foregoing reasons, in the solutions provided in the embodiments of the present invention, if an IO request needs to be sent to a physical NIC by using the user mode OVS, the IO request is directly converted, in the user mode, into a format that can be processed by the user mode OVS, and then is sent to the user mode OVS. This avoids a process of switching the IO request from the user mode to the kernel mode, and then from the kernel mode to the user mode, and further avoids the foregoing problems. Therefore, the performance of the virtual machine for processing the IO request can be effectively improved. For a specific implementation, refer to the following instances:

Embodiment 1

(14) A structure of a system for implementing a server virtualization scenario in this embodiment of the present invention is shown in FIG. 2. A user mode OVS implements network interworking between virtual switches, including virtual machines on a same host and virtual machines on different hosts. A virtual disk file of a virtual machine is stored on an Internet Protocol Storage Area Network (IPSAN) device that is connected to the virtual machine by using a network. An IO request processed by the virtual machine is sent to the IPSAN device by using the user mode OVS, to implement virtual storage and access. Based on the system structure shown in FIG. 2, the embodiments of the present invention provide an electronic device, and a specific implementation of the electronic device may be as follows:

(15) As shown in FIG. 3, an embodiment of the present invention provides an electronic device, and the electronic device includes a virtual machine 310, a hypervisor 320, and a hardware layer 330. The virtual machine 310 is constructed based on the hardware layer 330, and the hypervisor 320 implements data monitoring and transmission between the virtual machine 310 and the hardware layer 330. The hardware layer 330 includes a processor 331, a physical memory 332, a hard disk 333, a network interface device 334, and the like. The network interface device 334 may be specifically a physical NIC.

(16) The hypervisor 320 may operate in two modes: a user mode and a kernel mode. In this embodiment, to improve a capability of the virtual machine for processing an IO request, the hypervisor 320 is specifically configured to:

(17) receive an IO request sent by the virtual machine VM, and determine whether the IO request needs to be sent to the physical NIC (in this embodiment, the physical NIC may be one of the network interface device 334 in FIG. 3) by using a user mode Open vSwitch OVS, where the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts; and if the IO request needs to be sent to the physical NIC by using the user mode OVS, convert the IO request into an Internet Small Computer Systems Interface (iSCSI) command in a user mode, and then send the iSCSI command to the user mode OVS, so as to send the iSCSI command to the physical NIC by using the user mode OVS.

(18) Optionally, a specific implementation of determining, by the hypervisor 320, whether the IO request is to be sent to the physical NIC by using the user mode OVS is:

(19) determining disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located; determining, according to the disk information, whether the disk to be accessed by the IO request is a disk of a remote terminal; and if the disk to be accessed by the IO request is the disk of the remote terminal, determining that the IO request needs to be sent to the physical NIC by using the user mode OVS.

(20) Optionally, that the hypervisor 320 converts the IO request into the Internet Small Computer Systems Interface iSCSI command includes:

(21) converting the IO request into a Small Computer System Interface SCSI command; and

(22) adding an Internet Small Computer Systems Interface iSCSI header to the SCSI command to obtain the iSCSI command.

(23) A specific implementation of a response to the IO request is the same as that of a structure of the electronic device in the foregoing instance, but the hypervisor 320 processes, in a different manner, a response fed back by the physical NIC. Therefore, based on the structure shown in FIG. 3, the specific implementation of the response to the IO request may be as follows:

(24) The hypervisor 320 is configured to: receive an Internet Small Computer Systems Interface iSCSI packet returned by the physical NIC in response to the IO request; and convert the iSCSI packet into an IO response in the user mode, and then send the IO response to the virtual machine that initiates the IO request, where the iSCSI packet needs to be sent, by using the user mode Open vSwitch OVS, to the virtual machine that initiates the IO request, and the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts.

(25) Optionally, a specific implementation of converting, by the hypervisor 320, the iSCSI packet into the IO response in the user mode, and then sending the IO response to the virtual machine that initiates the IO request includes:

(26) converting the iSCSI packet into an SCSI response; and

(27) converting the SCSI response into the IO response, and sending the IO response to the virtual machine that initiates the IO request.

(28) In the solution provided in this embodiment of the present invention, if the IO request needs to be sent to the physical NIC by using the user mode OVS, the IO request is directly converted, in the user mode, into a format that can be processed by the user mode OVS, and then is sent to the user mode OVS. This avoids a process of switching the IO request from the user mode to the kernel mode, and then from the kernel mode to the user mode, thereby avoiding a prior-art problem that performance of a virtual machine of the user mode OVS for processing the IO request is relatively low. Therefore, the performance of the virtual machine for processing the IO request can be effectively improved.

Embodiment 2

(29) As shown in FIG. 4, this embodiment of the present invention provides an electronic device, and the electronic device may specifically include a determining module 401 and a conversion module 402.

(30) The determining module 401 is configured to: receive an IO request sent by a virtual machine VM, and determine whether the IO request needs to be sent to a physical NIC by using a user mode Open vSwitch OVS, where the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts.

(31) Optionally, when the determining module 401 determines whether the IO request needs to be sent to the physical NIC by using the user mode OVS, a specific implementation may be as follows:

(32) The determining module 401 is specifically configured to: determine disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located; determine, according to the disk information, whether the disk to be accessed by the IO request is a disk of a remote terminal; and if the disk to be accessed by the IO request is the disk of the remote terminal, determine that the IO request needs to be sent to the physical NIC by using the user mode OVS.

(33) The conversion module 402 is configured to: if that the IO request needs to be sent to the physical NIC by using the user mode OVS, convert the IO request into an Internet Small Computer Systems Interface iSCSI command in a user mode, and then send the iSCSI command to the user mode OVS, so as to send the iSCSI command to the physical NIC by using the user mode OVS.

(34) Optionally, the conversion module 402 is specifically configured to: convert the IO request into a Small Computer System Interface SCSI command, and add an Internet Small Computer Systems Interface iSCSI header to the SCSI command to obtain the iSCSI command.

Embodiment 3

(35) As shown in FIG. 5, this embodiment of the present invention provides an electronic device, and a specific implementation of the electronic device includes:

(36) a receiving module 501, configured to: receive an Internet Small Computer Systems Interface iSCSI packet returned by a physical NIC in response to an IO request, where the iSCSI packet needs to be sent, by using a user mode Open vSwitch OVS, to a virtual machine that initiates the IO request, and the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts; and

(37) a conversion module 502, configured to: convert the iSCSI packet into an IO response in a user mode, and then send the IO response to the virtual machine that initiates the IO request.

(38) Optionally, a specific implementation of converting the iSCSI packet into the IO response may be as follows:

(39) The conversion module 502 is specifically configured to: convert the iSCSI packet into an SCSI response, convert the SCSI response into the IO response, and send the IO response to the virtual machine that initiates the IO request.

Embodiment 4

(40) As shown in FIG. 6, the present invention further provides another electronic device, configured to execute a data transmission method in a virtual switch technology in the foregoing embodiments. The electronic device includes at least one processor 601 (for example, a CPU), at least one network interface 602 or another communications interface, a memory 603, and at least one communications bus 604 that is configured to implement connection and communication between these apparatuses. The processor 601 is configured to execute an executable module stored in the memory 603, for example, a computer program. The memory 603 may include a high-speed Random Access Memory (RAM), and may further include a nonvolatile memory, for example, at least one magnetic disk storage. The at least one network interface 602 (which may be wired or wireless) may implement a communicative connection between the system gateway and at least one other network element by using the Internet, a wide area network, a local network, a metropolitan area network, or the like.

(41) In some implementations, the memory stores a program 6031, the program may be executed by the processor, and the program includes:

(42) receiving an IO request sent by a virtual machine VM, and determining whether the IO request needs to be sent to a physical NIC by using a user mode Open vSwitch OVS, where the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts; and

(43) if that the IO request needs to be sent to the physical NIC by using the user mode OVS, converting the IO request into an Internet Small Computer Systems Interface iSCSI command in a user mode, and then sending the iSCSI command to the user mode OVS, so as to send the iSCSI command to the physical NIC by using the user mode OVS.

(44) Optionally, the determining whether the IO request needs to be sent to a physical NIC by using a user mode OVS includes:

(45) determining disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located, determining, according to the disk information, whether the disk to be accessed by the IO request is a disk of a remote terminal, and if the disk to be accessed by the IO request is the disk of the remote terminal, determining that the IO request needs to be sent to the physical NIC by using the user mode OVS.

(46) Optionally, the converting the IO request into an Internet Small Computer Systems Interface iSCSI command includes:

(47) converting the IO request into a Small Computer System Interface SCSI command; and

(48) adding an Internet Small Computer Systems Interface iSCSI header to the SCSI command to obtain the iSCSI command.

(49) Based on a structure shown in FIG. 6, to process a response that is to the IO request and that is returned by the physical NIC, correspondingly, the program 6031 stored by the memory further includes:

(50) receiving an Internet Small Computer Systems Interface iSCSI packet returned by the physical NIC in response to the IO request, where the iSCSI packet needs to be sent, by using the user mode Open vSwitch OVS, to the virtual machine that initiates the IO request, and the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts; and

(51) converting the iSCSI packet into an IO response in the user mode, and then sending the IO response to the virtual machine that initiates the IO request.

(52) Optionally, the converting the iSCSI packet into an IO response in the user mode, and then sending the IO response to the virtual machine that initiates the IO request includes:

(53) converting the iSCSI packet into an SCSI response; and

(54) converting the SCSI response into the IO response, and sending the IO response to the virtual machine that initiates the IO request.

Embodiment 5

(55) Based on apparatus structures provided in the foregoing embodiments, this embodiment of the present invention provides a data transmission method used in a virtual switch technology. The method specifically includes the following steps (an implementation procedure is shown in FIG. 7).

(56) The method provided in this embodiment of the present invention may be implemented based on the apparatus structures shown in FIG. 3, FIG. 4, and FIG. 6. Different apparatuses execute the method in this embodiment of the present invention by using different specific function modules. For a specific function module that implements the method of the present invention, reference may be made to specific descriptions of different apparatuses in Embodiment 1 to Embodiment 4. For ease of description, with reference to Embodiment 3, the following describes in detail the data transmission method used in the virtual switch technology provided in this embodiment of the present invention.

(57) Step 701: A hypervisor receives an IO request sent by a virtual machine VM, and determines whether the IO request needs to be sent to a physical NIC by using a user mode Open vSwitch OVS, where the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts.

(58) Optionally, the determining whether the IO request needs to be sent to a physical NIC by using a user mode OVS includes:

(59) determining disk information of a disk to be accessed by the IO request or a disk in which a file to be accessed by the IO request is located, determining, according to the disk information, whether the disk to be accessed by the IO request is a disk of a remote terminal, and if the disk to be accessed by the IO request is the disk of the remote terminal, determining that the IO request needs to be sent to the physical NIC by using the user mode OVS.

(60) Based on the system structure shown in FIG. 2, the remote terminal may be a device that is connected, by using a switch, to an electronic device that implements the method in this embodiment of the present invention.

(61) In this embodiment, if it is determined, according to the disk information, that the IO request is to access a local device disk, the IO request is directly forwarded to the physical NIC by using a kernel mode.

(62) Step 702: If the hypervisor determines that the IO request needs to be sent to the physical NIC by using the user mode OVS, the hypervisor converts the IO request into an iSCSI command in a user mode, and then sends the iSCSI command to the user mode OVS, so as to send the iSCSI command to the physical NIC by using the user mode OVS.

(63) To ensure that the IO request can be transmitted on a network, when the IO request is transmitted on different hosts, the IO request needs to be converted into the iSCSI command, and then the packet is converted into the IO request on a target server. In this embodiment, to convert an IO request sent by tapdisk2 into an iSCSI command that can be identified by the user mode OVS, in a solution provided in this embodiment, the IO request may be converted in the user mode.

(64) a1. Convert the IO request into a Small Computer System Interface (SCSI) command.

(65) Specifically, major and minor device numbers (which include an ID of a storage block device that initiates accessing and an ID of a storage block device that needs to be accessed by the IO request), a first sector, a request size, and whether the request is a request for a read operation or a request for a write operation that are corresponding to the IO request are obtained from the IO request.

(66) A specific implementation of converting the IO request into the SCSI command may be that the ID of the storage block device that needs to be accessed by the IO request is converted into a logical unit number (LUN) of a destination host in the corresponding SCSI command, the first sector needs to be converted into a physical disk address, the read operation or the write operation needs to be converted into an SCSI operation direction, and after the foregoing conversion is implemented, the content obtained after conversion is encapsulated into the SCSI command.

(67) a2. Convert the SCSI command into the iSCSI command. A specific implementation is:

(68) adding an iSCSI header to the SCSI command, where the iSCSI header is encapsulated according to an iSCSI protocol, and the iSCSI header includes a basic header segment (BHS), an additional header segment (AHS), a header-digest, a data-digest, and the like.

(69) Different from the IO request sending path shown in FIG. 1, in the method provided in this embodiment of the present invention, an IO request sent by a virtual disk service may be directly sent to the user mode OVS in the user mode. A specific schematic diagram may be shown in FIG. 8.

(70) According to the method provided in this embodiment of the present invention, the IO request that needs to be sent to the physical NIC by using the user mode OVS is directly converted, in the user mode, into a format that can be processed by the user mode OVS, and then is sent to the user mode OVS. This avoids a process of switching the IO request from the user mode to the kernel mode, and then from the kernel mode to the user mode. Therefore, performance of the virtual machine for processing the IO request can be effectively improved.

Embodiment 6

(71) As shown in FIG. 9, this embodiment of the present invention further provides a data transmission method used in a virtual switch technology. The method specifically includes the following steps.

(72) The method provided in this embodiment of the present invention may be implemented based on the apparatus structures shown in FIG. 3, FIG. 5, and FIG. 6. Different apparatuses execute the method in this embodiment of the present invention by using different specific function modules. For a specific function module that implements the method of the present invention, reference may be made to specific descriptions of different apparatuses in Embodiment 1 to Embodiment 4. For ease of description, with reference to Embodiment 3, the following describes in detail the data transmission method used in the virtual switch technology provided in this embodiment of the present invention.

(73) Step 901: A hypervisor receives an iSCSI packet returned by a physical NIC in response to an IO request, where the iSCSI packet needs to be sent, by using a user mode Open vSwitch OVS, to a virtual machine that initiates the IO request, and the user mode OVS implements network interworking between virtual machines on a same host or virtual machines on different hosts.

(74) Step 902: Convert the iSCSI packet into an IO response in a user mode, and then send the IO response to the virtual machine that initiates the IO request.

(75) In this embodiment, the converting the iSCSI packet into an IO response in a user mode, and then sending the IO response to the virtual machine that initiates the IO request includes:

(76) converting the iSCSI packet into an SCSI response; and

(77) converting the SCSI response into the IO response, and sending the IO response to the virtual machine that initiates the IO request.

(78) The method provided in this embodiment is a procedure in response to the IO request. A solution of this embodiment may be independently implemented, or may be combined with the method provided in Embodiment 1. When the method in this embodiment and the method in Embodiment 1 are combined, a complete process of initiating the IO request and responding to the request may be implemented.

(79) Different from the IO request sending path shown in FIG. 8, in the method provided in this embodiment of the present invention, an electronic device processes a response to an IO request, and a specific schematic diagram may be shown in FIG. IO.

(80) In the method provided in this embodiment of the present invention, when processing the response to the IO request, the electronic device directly processes and converts a returned packet in the user mode without context switching, thereby shortening a response processing procedure, and effectively improving performance of the virtual machine for processing the IO request.

(81) The foregoing one or more technical solutions in the embodiments of this application have at least the following technical effects:

(82) In the solutions provided in the embodiments of the present invention, if the IO request needs to be sent to the physical NIC by using the user mode OVS, the IO request is directly converted, in the user mode, into a format that can be processed by the user mode OVS, and then is sent to the user mode OVS. This avoids a process of switching the IO request from the user mode to the kernel mode, and then from the kernel mode to the user mode, thereby avoiding a prior-art problem that performance of a virtual machine of the user mode OVS for processing the IO request is relatively low. Therefore, the performance of the virtual machine for processing the IO request can be effectively improved.

(83) The embodiments in this specification are all described in a progressive manner, for same or similar parts in the embodiments, reference may be made to these embodiments, and each embodiment focuses on a difference from other embodiments. Especially, an apparatus embodiment is basically similar to a method embodiment, and therefore is described briefly; for related parts, reference may be made to partial descriptions in the method embodiment. The described apparatus embodiment is merely an example. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all the modules may be selected according to actual needs to achieve the objectives of the solutions of the embodiments. A person of ordinary skill in the art may understand and implement the embodiments of the present invention without creative efforts.

(84) A person of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments disclosed in this specification, units and algorithm steps may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on particular applications and design constraint conditions of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of the present invention.

(85) It may be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, reference may be made to a corresponding process in the foregoing method embodiments, and details are not described herein again.

(86) In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the unit division is merely logical function division and may be other division in an actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented by using some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms.

(87) The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual requirements to achieve the objectives of the solutions of the embodiments.

(88) In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit.

(89) When the functions are implemented in the form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer readable storage medium. Based on such an understanding, the technical solutions of the present invention essentially, or the part contributing to the prior art, or some of the technical solutions may be implemented in a form of a software product. The software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) to perform all or some of the steps of the methods described in the embodiments of the present invention. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc.

(90) The foregoing descriptions are merely specific implementations of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.