Electric power information system operation service link topology construction method and system

By dynamically building the service link topology of the power information system, using dependency update and threshold adjustment algorithms, the problem of high consumption of microservice topology diagrams for real-time aggregation of computing resources is solved, timely and accurate system status reflection is achieved, and fault location is improved and system availability.

CN119169144AActive Publication Date: 2024-12-20INFORMATION COMM COMPANY STATE GRID SHANDONG ELECTRIC POWER

Patent Information

Application Number
CN202411657677.2
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-11-20
Publication Date
2024-12-20
Estimated Expiration
2044-11-20

AI Technical Summary

Technical Problem

The real-time aggregation calculation of microservice topology maps in existing power information systems consumes a large amount of computing resources, resulting in the inability to respond to system abnormal state in time, affecting fault location and system availability.

Method used

Dynamically build service link topology through service program code and runtime link data, update the microservice relationship diagram using dependency, and optimize the monitoring cycle using threshold slow start time interval adjustment algorithm to generate a timely and accurate service link topology diagram .

Benefits of technology

It reduces computing resource consumption, improves the timeliness and accuracy of system status reflection, supports more effective fault positioning and performance optimization, and improves the availability and stability of the system.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN119169144A_ABST
    Figure CN119169144A_ABST
Patent Text Reader

Abstract

The invention belongs to the technical field of electric power information system operation, and particularly relates to an electric power information system operation service link topology construction method and system, and the method comprises the steps: obtaining service program data of electric power information system operation, and obtaining a cross-service function call relation; according to the obtained cross-service function calling relation, constructing a micro-service association relation graph of operation of the electric power information system; and according to the directed edge weight in the obtained micro-service association relation graph, obtaining the dependency degree between the micro-services, updating the constructed micro-service association relation graph based on the dependency degree, obtaining a service link topological graph, and completing the construction of the service link topology for the operation of the electric power information system.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The present invention belongs to the technical field of power information system operation, and in particular relates to a method and system for constructing a power information system operation service link topology. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] During the digital transformation process, the proportion of microservices and microapplications in the power information system has gradually increased, which has improved the scalability, maintainability and stability of the power information system. In order to support the development of operation and maintenance work, it is very necessary to build a service topology map for microservices. Usually, the service topology map is obtained by collecting the associations between microservices and real-time aggregation calculation to obtain a directed graph. The nodes of the graph are several independent microservices, and the edges of the graph represent the association between two microservices. However, the real-time aggregation calculation of the service topology consumes a lot of computing resources, and the periodic calculation method will cause the service topology to fail to timely display the system operation status at the most recent abnormal moment, which will affect the accuracy and timeliness of using the topology map to locate performance bottlenecks and faults, which is not conducive to shortening the troubleshooting time, thus affecting the availability of the entire power information system.

[0004] In a certain scenario, an electric power information system is composed of several microservices, each of which is independently deployed and maintained. The segmentation of services should be highly cohesive and loosely coupled, which is conducive to enhancing the independence and scalability of microservices and reducing fault propagation. However, during the microservice upgrade process, the boundaries between microservices gradually blur, and the relationship between microservices becomes more complex, with more cyclic calls and repeated calls. At this time, the use of real-time service topology map construction solutions consumes a lot of resources, and the use of periodic service topology construction solutions cannot timely and accurately reflect the system abnormal state at the time of possible system failures and anomalies, and cannot effectively provide strong support for the subsequent fault and performance bottleneck location, resulting in the availability of the electric power information system still has room for improvement.

[0005] The existing solution is to track the call information on the microservice link, pass it to the information collection module through http or gRPC, and then connect the corresponding microservices of the associated upstream and downstream calls in real time to form a directed graph; it is easy to build a microservice topology map in a timely manner, but it consumes a lot of computing resources and generates too much redundant data; at the same time, due to the lack of static analysis of service relationships and the fact that some microservices did not generate traffic during the detection period, there may be a small amount of omissions in the service association relationship, which affects the subsequent analysis and optimization of the power information system. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a method and system for constructing a service link topology for an electric power information system operation, which dynamically constructs a service link topology by using service program code and link data generated during operation, consumes fewer resources to generate the service link topology, and more comprehensively reflects the current operation status of the information system.

[0007] According to some embodiments, a first solution of the present invention provides a method for constructing a power information system operation service link topology, which adopts the following technical solution: A method for constructing a power information system operation service link topology, comprising: Obtain service program data running in the power information system and obtain cross-service function call relationships; According to the obtained cross-service function call relationship, a microservice association diagram of the power information system operation is constructed; The dependency between microservices is obtained according to the directed edge weights in the obtained microservice association graph, and the constructed microservice association graph is updated based on the dependency to obtain the service link topology graph, thereby completing the construction of the service link topology for the operation of the power information system.

[0008] As a further technical limitation, the obtained cross-service call relationship includes at least a service list and a call list; a microservice association relationship is preliminarily constructed based on the cross-service call relationship and the graph theory algorithm; that is, several services in the service list are regarded as nodes in the service association relationship, and each tuple in the call list is regarded as a directed edge in the service association relationship graph, the direction of the directed edge is set from the service caller to the callee, and the weight of the directed edge is set to an initial value to generate a directed graph; the generated directed graph is described using an adjacency matrix to obtain a microservice association relationship graph for the operation of the power information system.

[0009] As a further technical limitation, in the process of updating the constructed microservice association graph, the directed edge weights of the corresponding microservice association graph are updated according to the obtained dependencies between the microservices. If there are no directed edges in the microservice association graph, the current power information system has changed and the static microservice association graph needs to be rebuilt.

[0010] Furthermore, the link information of the current operating status of the power information system and its corresponding service link topology are obtained based on the obtained dependencies between the microservices, and the update time is determined based on the dependencies; when the power information system changes, the obtained service link topology changes accordingly until the update time is reached, completing the construction of the service link topology.

[0011] Furthermore, a threshold-based slow start time interval adjustment algorithm is used to calculate the next update time. When the update time is reached, the dependencies between the microservices are recalculated, and the dependencies between the microservices are obtained based on the obtained dependencies, and the next update time is obtained based on the dependencies.

[0012] As a further technical limitation, the dependency between the microservices is related to the microservice link information. The microservice link information is obtained based on the service mesh technology, and the dependency between the microservices is obtained according to the obtained link information and its weight ratio.

[0013] According to some embodiments, a second solution of the present invention provides a power information system operation service link topology construction system, which adopts the following technical solutions: A power information system operation service link topology construction system, comprising: An acquisition module configured to acquire service program data running in the power information system and obtain a cross-service function call relationship; A construction module is configured to construct a microservice association relationship graph for the operation of the power information system according to the obtained cross-service function call relationship; obtain the dependency between microservices according to the directed edge weights in the obtained microservice association relationship graph, update the constructed microservice association relationship graph based on the dependency, obtain a service link topology graph, and complete the construction of the service link topology for the operation of the power information system.

[0014] According to some embodiments, a third solution of the present invention provides a computer-readable storage medium, which adopts the following technical solution: A computer-readable storage medium stores a program, which, when executed by a processor, implements the steps in the method for constructing a power information system operation service link topology as described in the first solution of the present invention.

[0015] According to some embodiments, a fourth solution of the present invention provides an electronic device, which adopts the following technical solution: An electronic device comprises a memory, a processor and a program stored in the memory and running on the processor. When the processor executes the program, the steps in the method for constructing a power information system operation service link topology as described in the first solution of the present invention are implemented.

[0016] According to some embodiments, a fifth solution of the present invention provides a computer program product, which adopts the following technical solution: A computer program product includes software codes, wherein the program in the software codes executes the steps in the method for constructing a service link topology of an electric power information system as described in the first solution of the present invention.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention combines service program code and service configuration files to preliminarily construct a service association diagram to reduce possible service dependency omissions. By aggregating link call information of computing services, it supports dynamic updating of the association diagram to obtain a dynamic service topology diagram. Compared with the mainstream service topology diagram, a flexible monitoring strategy is designed, and a threshold-based monitoring cycle adjustment method is used to support changes to the method according to actual requirements in subsequent operation and maintenance work. The system topology relationship is displayed in a more timely and accurate manner, which provides strong support for subsequent fault location and abnormality location, and improves the availability and stability of the information system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0019] Figure 1 This is a flow chart of a method for constructing a service link topology for a power information system operation in Embodiment 1 of the present invention; Figure 2 A schematic diagram of detailed steps of a method for constructing a power information system operation service link topology in Embodiment 1 of the present invention; Figure 3 This is an architectural diagram of the method for constructing a service link topology in a power information system operation in Embodiment 1 of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0024] Embodiment 1 Embodiment 1 of the present invention introduces a method for constructing a power information system operation service link topology.

[0025] like Figure 1 and Figure 2 A method for constructing a power information system operation service link topology is shown, comprising: Step S01: Collect the code and configuration files of the service program, use the code analysis tool of the corresponding language to perform code analysis, and obtain the cross-service function call relationship; Step S02: construct a preliminary service association relationship graph through service discovery, registration results and function call relationships; Step S03: Collect service link data through a link tracking tool, use a threshold-based slow start algorithm to generate periodic aggregation calculations, and obtain the call relationship and dependency scores between microservices; Step S04: Update the calculation results to the initially established microservice association diagram to obtain a service link topology diagram for a certain time period.

[0026] This embodiment adopts Figure 3 The architecture shown implements the construction of the service link topology. The architecture diagram mainly includes two parts, namely, constructing a preliminary service association relationship diagram and updating the weights of the directed edges in the preliminary service association relationship diagram according to the actual running system status.

[0027] As one or more implementation modes, the specific process of step S01 is: Step S101: Collect code and configuration files; When the service association diagram is first established, it is necessary to collect all microservice program code files that need to be included in the service topology diagram within the information system, as well as related files related to service deployment, fault tolerance, network configuration, and security policy configuration. When subsequent services are updated or upgraded, or configuration service deployment, fault tolerance, network and security policy configuration are changed, only the changed parts need to be re-collected, and there is no need to re-collect the related code and configuration files that have not changed.

[0028] Step S102: Collect microservice registration and discovery information; The service registration and discovery center module maintains the relevant information of the services running in the information system. It collects service information and represents all service information as a list. , where A represents a service A. In the microservice architecture, A may have multiple different instances running on different host nodes, but in ListService, we represent these different instances as A.

[0029] Step S103: Analyze the code file and the configuration file.

[0030] R&D personnel and operation and maintenance personnel can manually analyze and annotate, use different code analysis tools, or use various algorithms (such as natural language processing algorithms, graph neural network algorithms, etc.) to extract function calls across services. The purpose of manual analysis and using tools or algorithms is to ultimately obtain a series of binary tuples, which can be represented as a call list. ,in It means that service A calls service B, that is, there is an association relationship between service A and service B.

[0031] It should be noted that the codes collected in this embodiment include but are not limited to languages ​​in the form of C, C++, Java, Python, Go, etc., and the code analysis tools that can be used include but are not limited to SonarQube, Dynatrace, Pylint, NDepend, CppDepend, GoMetaLinter. The configuration files that need to be collected include application configuration files (application.properties, env), API gateway configuration files (kong.yml, application.yml), container orchestration configuration files (YAML files), log and monitoring configuration files (logback.xml, prometheus.yml), etc.

[0032] As one or more implementation modes, in step S02, after obtaining the service list and the call list, a service association graph is preliminarily constructed using an algorithm based on graph theory. In the process of generating the graph, several services in the service list are regarded as nodes in the service association graph, and each tuple in the call list is regarded as a directed edge in the graph. The direction of the directed edge is from the service caller to the callee, and the weight of the directed edge is set to an initial value of 0. After the graph is generated, a directed graph can be obtained. In the practice of applying the present disclosure, the connectivity of the entire graph is relatively complete and the complexity of the graph is relatively high, so it is recommended to use the form of an adjacency matrix to describe the service association graph.

[0033] In this embodiment, a directed graph generation algorithm in graph theory is used to generate a preliminary directed graph based on the results of microservice registration and discovery and the function call relationship. The nodes of the graph represent a microservice (which can actually be composed of multiple pods deployed on multiple nodes), and the weights of the directed edges of the graph are initial values. The connectivity of the graph should be related to the specific service division method and business logic, and the complexity of the graph is related to the complexity of the call relationship between microservices.

[0034] As one or more implementation modes, the specific process of step S03 is: Step S301: Link information collection and transmission; Use service mesh technology to collect link information and deploy a proxy for each service instance. The proxy intercepts requests entering the service instance and forwards the requests to the corresponding service; the proxy intercepts requests from the service instance and forwards the requests to the proxy of the target service. The proxy automatically injects and propagates tracing information when intercepting incoming service requests, injects tracing headers (such as X-B3-TraceId, X-B3-SpanId, X-B3-ParentSpanId) into HTTP requests, and uses metadata headers to inject tracing information into gRPC requests. The proxy collects TraceID, SpanID, ParentSpanID, and other metadata. The tracing data is formatted and passed to the remote server through the corresponding HTTP\gRPC protocol.

[0035] Step S302: Link information aggregation calculation.

[0036] Perform stream computing at the remote server, aggregate and calculate information such as TraceID, SpanID, ParentSpanID, and build a complete link for a call. The link is represented as a tree in the data structure, and the nodes on the tree represent a service instance. Since the nodes of the service topology represent microservices, it is necessary to refer to the instance information of the microservice registration and discovery center to convert the instance information in the node into the corresponding service information. When calculating the dependency between services, you can refer to several different performance parameters or operating indicators, such as Call frequency (the number of calls within a specified time period), Request / Response Time (the average response time within a specified time period), Error rate (the proportion of abnormal calls within a specified time period), Network traffic (the amount of data transmitted within a specified time period), etc.

[0037] In this embodiment, the dependency between services can be obtained by weighted summation, that is, the dependency between services is ; Among them, CF represents the call frequency, ER represents the error rate, and RT represents the request response time. They represent the call frequency weight, error rate weight and request response time weight respectively. These weights can be obtained by the proportion of various performance parameters (or operating indicators) in the operation of the information system; the dependency is obtained by the weighted sum of the performance parameters (or operating indicators) and their weights, where the weight of the performance parameter is the proportion of the performance parameter in the dependency calculation. The dependency calculation formula can be improved in various forms in practice to adapt to the specific operation requirements of different information systems. After obtaining a final dependency score, the initially generated links are disassembled to obtain a triple list .

[0038] It should be noted that in step S301, link data is collected through the link tracking tool, and it is necessary to record the start time, end time, call initiator, callee, link unique identifier, span unique identifier, label, metadata, status information, instance name and other context information of each link call.

[0039] As one or more implementation modes, the specific process of step S04 is: Step S401: updating the service association relationship diagram to obtain a service topology diagram; After obtaining the triple list, the service association graph will be updated according to the service dependency information in the triple list, and the corresponding directed edge weights will be updated with the calculated dependency. If there are edges that do not exist in the association graph, it means that the current information system has changed, which may be a service upgrade or a change in network security policy, and the static association graph needs to be rebuilt.

[0040] Step S402: persistently store the aggregated computing results and the service topology map.

[0041] After each convergence calculation, the link information of the current state and the corresponding service topology diagram will be obtained. These key information need to be persistently stored to provide data support for subsequent adjustment of dynamic monitoring strategies, and to facilitate fault tracing when an abnormality occurs in the information system.

[0042] In the judgment of reaching the update time, this embodiment uses a slow start algorithm to determine the topology information update cycle of one or more microservices in the next stage by comparing the relationship between the dependency scores and the threshold between the services. For services involving dependency scores greater than the threshold, the slow start algorithm is used to implement a more stringent monitoring strategy for the service, which is conducive to improving the timeliness of system status monitoring; for services with dependency scores less than the threshold, a relatively loose monitoring strategy is adopted, which is conducive to saving computing resources. The threshold-based slow start algorithm is used to calculate the next update time. When the update time is reached, the dependency relationship between the services is recalculated to obtain the dependency score, and the next update time is calculated based on the dependency score.

[0043] In this embodiment, link data within a certain time period is selected, and the collected link data is converted, for example, the instance name is matched with the microservice name, and useless labels, status information, metadata, and context information are removed to obtain a triplet, which can be expressed in the form of (Ax, By, De). In this scheme, it means that within the specified time, there is an instance x of microservice A that calls an instance y of microservice B, that is, there is an association relationship between microservice A and microservice B, and the dependency is De.

[0044] The slow start algorithm based on threshold in this embodiment is as follows: Input: De: Dependency score, default value is 0; T: Threshold size, user-defined parameter; MaxP: Maximum time interval for service topology update, unit is minute; P: Update time interval obtained from the previous calculation, default value is P0, unit is minute; Output: Pn: Next update time, unit is minute; Judgment logic: (1) Compare the magnitudes of De and T. If De < T, then jump to step 2; otherwise, jump to (3); (2) Analyze the relationship between P and MaxP. If P < (MaxP / 2), then P = P * 2; if (MaxP / 2) < P < MaxP, then P = P + 1; if P = MaxP, then P remains unchanged; after adjusting the value of P, jump to step 4; (3) Set P to the default minimum time interval P0; (4) Output P.

[0045] This embodiment combines the slow start time interval adjustment algorithm based on threshold, and uses the service program code and the link data generated during runtime to dynamically construct the service link topology. While occupying less computing resources, it can ensure the timeliness of key service topology updates, providing strong support for the subsequent operation and maintenance work.

[0046] Embodiment Two Embodiment Two of the present invention introduces a system for constructing a service link topology for the operation of a power information system.

[0047] A system for constructing a service link topology for the operation of a power information system includes: An acquisition module, which is configured to acquire the service program data of the operation of the power information system to obtain the cross-service function call relationship; A construction module, which is configured to construct a microservice association relationship graph for the operation of the power information system according to the obtained cross-service function call relationship; obtain the dependency between microservices based on the directed edge weights in the obtained microservice association relationship graph, and update the constructed microservice association relationship graph based on the dependency to obtain a service link topology graph, thereby completing the construction of the service link topology for the operation of the power information system.

[0048] The detailed steps are the same as those of the method for constructing a service link topology for the operation of a power information system provided in Embodiment One, and will not be elaborated here.

[0049] Embodiment Three Embodiment Three of the present invention provides a computer-readable storage medium.

[0050] A computer-readable storage medium stores a program thereon, and when the program is executed by a processor, the steps in the method for constructing a power information system operation service link topology as described in Embodiment 1 of the present invention are implemented.

[0051] The detailed steps are the same as the method for constructing the power information system operation service link topology provided in Example 1, and will not be repeated here.

[0052] Embodiment 4 A fourth embodiment of the present invention provides an electronic device.

[0053] An electronic device comprises a memory, a processor and a program stored in the memory and running on the processor, wherein when the processor executes the program, the steps in the method for constructing a power information system operation service link topology as described in Embodiment 1 of the present invention are implemented.

[0054] The detailed steps are the same as the method for constructing the power information system operation service link topology provided in Example 1, and will not be repeated here.

[0055] Embodiment 5 Embodiment 5 of the present invention provides a computer program product.

[0056] A computer program product includes software codes, wherein the program in the software codes executes the steps in the method for constructing a power information system operation service link topology as described in the first embodiment of the present invention.

[0057] The detailed steps are the same as the method for constructing the power information system operation service link topology provided in Example 1, and will not be repeated here.

[0058] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A method for constructing a power information system operation service link topology, characterized in that: include: Obtain service program data running in the power information system and obtain cross-service function call relationships; According to the obtained cross-service function call relationship, a microservice association diagram of the power information system operation is constructed; The dependency between microservices is obtained according to the directed edge weights in the obtained microservice association graph, and the constructed microservice association graph is updated based on the dependency to obtain the service link topology graph, thereby completing the construction of the service link topology for the operation of the power information system.

2. A method for constructing a power information system operation service link topology as claimed in claim 1, characterized in that: The obtained cross-service call relationship includes at least a service list and a call list; a microservice association relationship is preliminarily constructed based on the cross-service call relationship and the graph theory algorithm; that is, several services in the service list are regarded as nodes in the service association relationship, and each tuple in the call list is regarded as a directed edge in the service association relationship graph, the direction of the directed edge is set from the service caller to the callee, and the weight of the directed edge is set to the initial value to generate a directed graph; the generated directed graph is described using an adjacency matrix to obtain a microservice association relationship graph for the operation of the power information system.

3. A method for constructing a power information system operation service link topology as claimed in claim 1, characterized in that: In the process of updating the constructed microservice association graph, the directed edge weights of the corresponding microservice association graph are updated according to the obtained dependencies between the microservices. If there are no directed edges in the microservice association graph, the current power information system has changed and the static microservice association graph needs to be rebuilt.

4. A method for constructing a power information system operation service link topology as claimed in claim 3, characterized in that: According to the obtained dependencies between microservices, the link information of the current operation status of the power information system and its corresponding service link topology are obtained, and the arrival update time is determined based on the dependencies; When the power information system changes, the obtained service link topology map changes accordingly until the update time is reached, completing the construction of the service link topology.

5. A method for constructing a power information system operation service link topology as claimed in claim 4, characterized in that: A threshold-based slow start time interval adjustment algorithm is used to calculate the next update time. When the update time is reached, the dependencies between microservices are recalculated, and the dependencies between microservices are obtained based on the obtained dependencies. The next update time is obtained based on the dependencies.

6. A method for constructing a power information system operation service link topology as claimed in claim 1, characterized in that: The dependency between the microservices is related to the microservice link information. The microservice link information is obtained based on the service grid technology, and the dependency between the microservices is obtained according to the obtained link information and its weight ratio.

7. A power information system operation service link topology construction system, characterized in that: include: An acquisition module configured to acquire service program data running in the power information system and obtain a cross-service function call relationship; A construction module configured to construct a microservice association relationship graph of the power information system operation according to the obtained cross-service function call relationship; The dependency between microservices is obtained according to the directed edge weights in the obtained microservice association graph, and the constructed microservice association graph is updated based on the dependency to obtain the service link topology graph, thereby completing the construction of the service link topology for the operation of the power information system.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for constructing a power information system operation service link topology as described in any one of claims 1 to 6 are implemented.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of the method for constructing a power information system operation service link topology according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising software code, characterized in that The program in the software code executes the steps of the method for constructing a power information system operation service link topology according to any one of claims 1 to 6.

Citation Information

Patent Citations

  • Method and device for searching abnormal root cause nodes of micro-service system

    CN110888755A

  • Topological diagram drawing method and device

    CN112615743A

  • Fault root cause positioning method and system for micro-service architecture information system

    CN112698975A

  • Abnormal intelligent positioning method and device for micro-service call chain, and storage medium

    CN117112282A

  • Topology discovery method and system for micro-service remote call relationship

    CN118250177A

Cited By

  • Networking type energy storage inverter control method based on complex network space-time optimization

    CN120834603A