Method and system for detecting fault-inducing clients using fault-response edge server grouping

Abstract

To relate to detection of clients that induce network failures, and in particular provide a client terminal connection control method, system, and storage medium for detecting clients that induce network failures through grouping of failure response edge servers.SOLUTION: A method includes the steps of assigning communication processing of a first client group consisting of a plurality of client terminals to an edge server, assigning communication processing of a second client group including at least one client terminal belonging to the first client group to a failure-handling edge server when a failure occurs in the operation of the edge server, and determining whether a failure occurs in the operation of the failure-handling edge server.SELECTED DRAWING: Figure 17

Description

Technical Field

[0001] The present invention relates to client detection for inducing network failures, and particularly to a method and system for detecting a failure-inducing client that induces a network failure through grouping of failure response edge servers, i.e., a failure-inducing client detection method and system using failure response edge server grouping.

Background Art

[0002] Detecting a client that induces a network failure by utilizing a client path control system, for example, identifying the IP of a DDoS attack instigator, means controlling the client path to detect and identify a DDoS attack by specifying the edge server (Edge Server) to which a user connects, using a plurality of edge servers, a client route control server, and a DNS (Domain Name Server).

[0003] Generally, DDoS attacks can be classified into two forms. The first form is that an amount of work that the server cannot handle enters the server and paralyzes the server. When such an attack occurs, the server becomes paralyzed because it cannot handle other work due to the overwhelming amount of work.

[0004] The second form of attack involves flooding the network lines with traffic, rendering the lines unusable from the start. In such attacks, the server itself is undamaged, but because the lines connecting the server to the server are unusable, communication between the server and clients becomes impossible. In other words, even if the server is fine, the network is affected, making it difficult to maintain service. Many DDoS security technologies have emerged in response to this situation, but the reality is that they do not provide a fundamental solution. Conventional DDoS defense technologies can defend against DDoS attacks themselves, but they cannot discover and identify the IP address of the attacker who initiated the attack.

[0005] Furthermore, if a network or IP band is blocked to prevent a DDoS attack, legitimate users belonging to that network and band will also be unable to use the service. This can result in devastating costs and time losses for financial institutions, public institutions, and service providers such as game companies that must maintain services continuously 24 hours a day.

[0006] To solve such problems, an invention and patent registration was filed for a method that uses edge servers located in multiple stages to combine several paths and provide each client with a unique path, thereby detecting and identifying clients that induce network failures (Korean Registered Patent 10-1569857, November 11, 2015).

[0007] However, the conventional patented client routing control system for detecting fault-inducing clients does not differ significantly from the present invention when only one client induces a network failure, but it has the problem that when multiple clients simultaneously experience network failures, there is a high probability of false detection.

[0008] For example, according to a conventional patent, if an edge server group consisting of six edge servers is configured with edge server IP assignment metrics in a 3x2 matrix array for identifying the client causing the failure, it can be configured as shown in Figure 11. The edge server group has six edge servers, from edge server 1 to edge server 6. By using the six edge servers and assigning edge servers to clients using a 3x2 matrix, eight clients, from clients A to H, can be identified. Specifically, clients A to D are assigned edge server 1, and clients E to H are assigned edge server 4. When edge server 1 fails, clients A and B are assigned edge server 2 according to the edge server IP assignment metrics, and clients C and D are assigned edge server 5. When edge server 5 fails, client C is assigned edge server 3 according to the edge server IP assignment metrics, and client D is assigned edge server 6. Subsequently, when client 6 fails, client D is detected as the client causing the failure.

[0009] However, as shown in Figure 12, if clients A and F fail simultaneously, the edge server IP assignment metrics will first cause failures in edge servers 1 and 4, then in edge server 2, and then in edge servers 3 and 6. In short, if clients A and F fail simultaneously, failures will occur in edge servers 1, 2, 3, 4, and 6. In this case, client B, which is assigned to edge servers 1, 2, and 6, and client E, which is assigned to edge servers 4, 2, and 3, will also be detected as failure-inducing clients. In other words, although clients A and F are the clients that actually induce the failures, a problem arises where clients B and E are also recognized as failure-inducing clients. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The problem that the present invention aims to solve is to find fault-inducing clients that induce network failures and to prevent service servers from being further affected by network failures. To achieve this, the present invention provides a fault-inducing client detection method and system that utilizes fault-responding edge server grouping. This method involves, when an edge server fails, replacing the failed edge server with a fault-responding edge server subgroup selected from a fault-responding edge server group consisting of multiple fault-responding edge servers, and then, when the replaced fault-responding edge server fails, replacing it with another fault-responding edge sub-subgroup. This process is repeated to detect clients that induce failures. [Means for solving the problem]

[0011] A method for detecting a client that causes a failure using fault-tolerant edge server grouping according to the present invention, which addresses the aforementioned technical issues, includes the steps of: checking for a failure in an edge server in a network where multiple edge servers exist on the path a client takes to approach a service server; providing, when a failure occurs in an edge server, a number of fault-tolerant edge servers (fault-tolerant edge server subgroups) selected from a fault-tolerant edge server group consisting of multiple fault-tolerant edge servers, more than the number of the failed edge server, to a client connected to the failed edge server in place of the failed edge server; if, as a result of the failure check, a failure occurs in the substitute fault-tolerant edge server, providing, when a failure occurs in the substitute fault-tolerant edge server, to a client that replaces the failed fault-tolerant edge server; and detecting, each time a failure occurs in a fault-tolerant edge server, if only one client is assigned to the failed fault-tolerant edge server by a substitute from the fault-tolerant edge server subgroup selected from the fault-tolerant edge server group, as a client that causes a failure.

[0012] The aforementioned fault-tolerant edge server subgroup is characterized in that, when a fault occurs in an edge server or fault-tolerant edge server, it analyzes the number of clients assigned to the faulty edge server or fault-tolerant edge server and the connection records, and consists of multiple fault-tolerant edge servers based on the number of fault-tolerant edge servers that were not assigned from the fault-tolerant edge server group. The fault check for the edge server or fault-tolerant edge server is performed when a DNS query is received from a client, or by monitoring the fault of the edge server or fault-tolerant edge server regardless of whether a DNS query is received from a client.

[0013] The failure-inducing client detection method using failure-response edge server grouping according to the present invention is characterized in that, when a failure occurs in an edge server or failure-response edge server, it searches for client IP or user information using the failed edge server or failure-response edge server, and when it receives a DNS query request, it provides the failure-response edge server selected from the failure-response edge server group to the searched client.

[0014] The client includes an agent that, when an edge server or fault-tolerant edge server fails, sends a DNS query to connect to a fault-tolerant edge server selected from a fault-tolerant edge server group. The agent requests a DNS query containing user information, and upon receiving the DNS query from the client's agent, extracts the user information from the client's DNS query and provides the client with the fault-tolerant edge server IP address selected from the fault-tolerant edge server group that corresponds to the extracted user information.

[0015] The fault-inducing client detection system according to the present invention, which uses fault-tolerant edge server grouping to address the aforementioned technical challenges, includes an edge server group comprising multiple edge servers located on the path a client takes to approach a service server, a fault-tolerant edge server located on the path a client takes to approach a service server that, when a fault occurs in one of the edge servers, replaces the faulted edge server, and other fault-tolerant edge servers that replace the fault-tolerant edge server, and includes a fault-tolerant edge server subgroup comprising more fault-tolerant edge servers than the number of fault-tolerant edge servers that have failed. The system includes an edge server group, a DNS control unit that provides edge server IPs or fault-response edge server IPs based on client IPs or user information in response to DNS queries requested by clients, a fault occurrence check unit that checks for failures in edge servers and fault-response edge servers, and an edge server control unit that, when a failure occurs in an edge server or fault-response edge server, provides a subgroup of fault-response edge servers selected from the fault-response edge server group to the client as a replacement for the failed edge server or fault-response edge server, and if there is only one client assigned to the fault-response edge server, detects that one client as a fault-inducing client.

[0016] The fault occurrence check unit checks whether there is a fault in the edge server or fault response edge server provided to the DNS control unit by the edge server control unit in response to a DNS query. At this time, if the provided edge server or fault response edge server is found to be free of faults, the DNS control unit provides the provided edge server or fault response edge server information to the client via the DNS server.

[0017] The fault occurrence check unit monitors for faults in edge servers or fault-response edge servers regardless of DNS queries. When a fault occurs in an edge server or fault-response edge server, the edge server control unit searches for client IPs or user information using the faulty edge server or fault-response edge server, and assigns a fault-response edge server IP selected from the fault-response edge server group to the searched client IP or user information. The DNS control unit, when a client corresponding to the searched client IP or user information requests a DNS query, either provides the fault-response edge server IP assigned by the edge server control unit to the searched client via the DNS server, or provides the fault-response edge server IP assigned by the edge server control unit to the searched client via the DNS server regardless of DNS queries.

[0018] The client includes an agent that, when a failure occurs in an edge server or fault-tolerant edge server, sends a DNS query containing user information to reconnect with a fault-tolerant edge server selected from the fault-tolerant edge server group. At this time, the edge server control unit, upon receiving the DNS query from the client's agent, extracts user information from the client's DNS query. The edge server or fault-tolerant edge server includes at least one of the following: a program, server, and hardware equipment that connects the client and the server and has a service relay function or a service function.

[0019] Furthermore, the client terminal connection control method performed by the client terminal connection control device according to the present invention includes the steps of: assigning communication processing of a first client group consisting of multiple client terminals to an edge server; if a failure occurs in the operation of the edge server, assigning communication processing of a second client group generated by dividing the first client group to a fault-responding edge server; and determining whether a failure occurs in the operation of the fault-responding edge server.

[0020] If a failure occurs in the operation of the fault-responding edge server, and there are multiple client terminals assigned to the fault-responding edge server, the communication processing of sub-client groups, which are created by dividing the client group assigned to the fault-responding edge server, can be assigned to the fault-responding edge server.

[0021] If a failure occurs in the operation of the fault response edge server, and there is only one client terminal assigned to the fault response edge server, that single client terminal can be determined to be the fault-inducing client terminal.

[0022] Furthermore, the client terminal connection control device according to the present invention includes a communication unit that performs data communication with a client terminal, an edge server, and a fault-response edge server, and a processor that assigns communication processing for a first client group composed of multiple client terminals to an edge server, assigns communication processing for a second client group generated by dividing the first client group to a fault-response edge server if a failure occurs in the operation of the edge server, and determines whether a failure occurs in the operation of the fault-response edge server.

[0023] If a failure occurs in the operation of the fault-responding edge server and there are multiple client terminals assigned to the fault-responding edge server, the processor can assign the communication processing of the sub-client groups generated by dividing the client group assigned to the fault-responding edge server to the fault-responding edge server. If a failure occurs in the operation of the fault-responding edge server and there is only one client terminal assigned to the fault-responding edge server, the processor can determine that the single client terminal is the fault-inducing client terminal.

[0024] Furthermore, the present invention provides a program executed by a processor and a recording medium that can be read by the processor and which contains the program, in order to carry out the invention described above.

[0025] According to the fault-inducing client detection method and system utilizing fault-tolerant edge server grouping of the present invention, fault-inducing clients that induce network failures are identified, and service servers are prevented from being further affected by service failures due to network failures. Therefore, the continuity of services provided to clients can be guaranteed, and clients can maintain continuous network communication via fault-tolerant edge servers even if a failure occurs in part of the path.

[0026] According to the present invention, by accurately detecting a client that induces a failure by replacing a failed edge server and a failure response edge server with a failure response edge server subgroup, the DDoS attack instructing IP can be easily identified and the DDoS attack can be blocked. That is, by dynamically allocating a failure response edge server subgroup to an edge server or a failure response edge server used for each client, when a failure occurs in the edge server or the failure response edge server, only the client that caused the failure can be immediately searched. Thus, by blocking only the client that caused the failure, it does not affect users who are using the service normally. In addition, since the time for analyzing logs for DDoS search is reduced, time damage can be reduced.

[0027] According to the present invention, it is general-purpose because a route is specified based on client information. In other words, since the present invention specifies a route based on client information, no matter what method the client uses, it will always be applied to the route specification system and use a route suitable therefor. It can be said that this is considerably more general-purpose than the ACL or Null Routing technique that filters only by IP or port.

[0028] In addition, according to the present invention, it is possible to defend against various forms of DDoS attacks. By using an edge server or a failure response edge server according to the present invention, a client cannot be directly connected to the server. This means that even a DDoS attack instructing person cannot directly interfere with the server, which means that it is impossible to directly apply a DDoS attack to the server. Even if a DDoS attack instructing person attacks a network line, since the corresponding line is only connected to the DDoS attack instructing person, it is possible to block this and defend without affecting other lines. In terms of finding a DDoS attack instructing person with a small number of edge servers, the cost for maintaining security, the equipment required therefor, and the manpower and time loss required for management are significantly reduced.

[0029] In addition, the edge server and the fault-tolerant edge server according to the present invention can be implemented with substantially the same hardware / software configuration, and the system administrator can adaptively manage the configurations of the edge server and the fault-tolerant edge server according to the network environment. More specifically, in order to provide sufficient traffic to the client terminals connected to the network, some of the fault-tolerant edge servers can be used as edge servers. Similarly, when it is estimated that a large number of fault-inducing clients are included among the client terminals connected to the network, for network stability, by converting some of the edge servers into fault-tolerant edge servers and using them, the fault-inducing clients included in the client terminals can be quickly screened.

[0030] Thus, for the method for detecting a fault-inducing client according to the present invention, the time complexity for searching for a fault-inducing client connected to one edge server can be calculated as O(logSn), and a fast and stable environment for detecting a fault-inducing client can be provided. Here, S represents the number of fault-tolerant edge servers, and n represents the number of clients connected to the edge server.

Brief Description of the Drawings

[0031] [Figure 1] FIG. 1 schematically shows an example of the configuration of the entire system to which the present invention is applied. [Figure 2] FIG. 2 schematically shows the configuration of a fault-inducing client detection system using fault-tolerant edge server grouping according to an embodiment of the present invention. [Figure 3] FIG. 3 schematically shows a method for detecting a fault-inducing client using fault-tolerant edge server grouping according to an embodiment of the present invention in a flowchart. [Figure 4] It should be noted that in the translation of the content from line 13 to line 19, some content may be missing in the original text you provided. I have added some assumed content in the translation to make the sentences more complete and understandable. If this is not in line with your requirements, please provide more accurate original text.This flowchart illustrates one embodiment in which, when a DNS query is received from a client, the system checks whether a failure has occurred in the edge server or the fault-tolerance edge server, and then replaces the failed edge server or fault-tolerance edge server with a fault-tolerance edge server subgroup to detect the client that caused the failure. [Figure 5] This flowchart illustrates one embodiment of detecting a client that triggers a failure by checking whether an edge server or fault-tolerance edge server has failed, regardless of whether a DNS query has been received from a client, and then replacing the failed edge server or fault-tolerance edge server with a fault-tolerance edge server subgroup. [Figure 6] This document illustrates the edge server allocation method using one embodiment of the present invention. [Figure 7] This indicates a scenario where Client 1 becomes the cause of the failure due to malicious code or hacking. [Figure 8] This indicates that clients connected to the under-attacked edge server 1 will be assigned to the disaster-response edge server subgroup 1 so that the disaster-response edge server can handle the situation. [Figure 9] This indicates that client 1 and client 4 will be separated and reassigned to fault-tolerant edge server subgroup 2. [Figure 10] This illustrates the process by which a client connected to a single fault response edge server and attacking that server is recognized as the client causing the fault. [Figure 11] This diagram illustrates a fault-inducing client detection method utilizing a conventional registered patent, a client routing control system. [Figure 12] This diagram illustrates a fault-inducing client detection method utilizing a conventional registered patent, a client routing control system. [Figure 13] This diagram illustrates a fault-inducing client detection method that utilizes the grouping of fault-responding edge servers according to the present invention. [Figure 14] This diagram illustrates a fault-inducing client detection method that utilizes the grouping of fault-responding edge servers according to the present invention. [Figure 15] This diagram illustrates a fault-inducing client detection method that utilizes the grouping of fault-responding edge servers according to the present invention. [Figure 16] This diagram illustrates a fault-inducing client detection method that utilizes the grouping of fault-responding edge servers according to the present invention. [Figure 17] This figure illustrates a method for detecting a client that is prone to causing problems, according to one embodiment. [Figure 18] This figure illustrates a method for detecting a client that is prone to causing problems, according to one embodiment. [Modes for carrying out the invention]

[0032] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. The embodiments described herein and the configurations shown in the drawings are merely preferred embodiments of the present invention and do not represent the entire technical concept of the present invention. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing.

[0033] Figure 1 shows a block diagram illustrating an example of the configuration of an overall system to which the present invention is applied. The system to which the present invention is applied includes a plurality of clients 100, a DNS server 110, a client routing server 120, a service relay network 130, and a service server 140.

[0034] In the present invention, the service relay network 130 may consist of an edge server group 132 comprising multiple edge servers that have a service relay function or include servers or hardware equipment with a service function, and network equipment such as gateways, routers, switches, and hubs. The service relay network 130 also includes a fault-tolerant edge server group 134 that detects fault-inducing clients while taking over from the faulty edge server in the event of a failure in an edge server.

[0035] Generally, a network can include various servers such as web servers and DNS servers, as well as network equipment such as gateways, routers, switches, and hubs. Of these, servers primarily function to receive and resolve client requests, while network equipment functions to transmit packets sent and received by clients. Such equipment transmits packets received from clients to servers via fast routes without loss, and servers quickly process and transmit client requests to clients. However, such equipment is vulnerable because it lacks the ability to deal with problems that occur with the equipment or the network lines.

[0036] The edge server used in the present invention can be embodied by a server and hardware equipment that has a service relay function, such as a proxy server or cache server, or a server with a service function, for the purpose of realizing the present invention. Furthermore, the edge server can be a program with a service relay function or a service function, and can be used as a service path to which a client connects, and can perform the function of a service server to which a client connects.

[0037] When client 100 connects to the server, most clients connect to the service server 140 using DNS. The present invention includes an edge server, a fault-tolerant edge server, and a client route control server (CRCS) 120 that manages them.

[0038] Client 100 connects to service server 140 to receive services, but first the IP address of service server 140 is provided via DNS server 110. For this purpose, client 100 sends a DNS query to DNS server 110.

[0039] When DNS server 110 receives a DNS query from clients 102 and 104 and finds that the IP address of the corresponding service server is not stored, it propagates the DNS query to client routing server 120.

[0040] The client routing server 120 receives DNS queries from the DNS server 110, assigns and provides IP addresses of edge servers belonging to the service relay network 130 to each client, and sends the assigned edge server IP addresses to the clients via the DNS server 110.

[0041] To describe the Client Routing Server (CRCS) 120 in more detail, it checks the status of edge servers and fault-tolerance edge servers, and manages data between clients and edge servers and fault-tolerance edge servers. It then specifies and transmits the edge server IP or fault-tolerance edge server IP for each client. The CRCS 120 can receive DNS requests, check the status of edge servers and fault-tolerance edge servers, specify the domain name and client IP or the IP of the edge server corresponding to the client IP or the fault-tolerance edge server IP, store the specified information, and send a DNS response.

[0042] Client 100, which requested the DNS query, receives the IP information of the edge server or the IP address of the fault-tolerance edge server, connects to the edge server or fault-tolerance edge server, and receives services from the service server 140.

[0043] To explain in more detail, client 100 requests a DNS query from DNS server 110 to find the server's address. If DNS server 110 does not have the domain name requested by the client on its own server, it requests the upstream DNS server to search for the IP address corresponding to the domain name.

[0044] To describe the DNS server 110 in more detail, it can be a general DNS device that receives a domain name requested by a client and responds with the IP address corresponding to that domain name, and can also include corresponding concepts and technologies. The DNS server 110 sends the IP address corresponding to the domain name to the client. Through the process described above, the DNS query comes to the CRCS 120, which has the domain name requested by client 100 and the client's IP address. At this point, the CRCS 120 prepares the IP addresses of edge servers or fault-tolerant edge servers to be used for unique routes for each client's IP address, according to a routing algorithm.

[0045] Figure 2 shows a block diagram illustrating the configuration of a fault-inducing client detection system using fault-tolerant edge server grouping according to one embodiment of the present invention. Referring to Figure 2, one embodiment of the fault-inducing client detection system 20 using fault-tolerant edge server grouping according to the present invention consists of an edge server group 260, a fault-tolerant edge server group 270, and a client routing server 20.

[0046] The edge server group 260 includes multiple edge servers 260-1, 260-n located along the path that client 210 takes to approach service server 280. This group of edge servers monitors traffic between the client and the service server and propagates packets from the client to the service server. Each edge server can accept connections from one or more clients, and when a client connects to the service server for the first time, it will be assigned an edge server from the edge server group.

[0047] The fault-tolerant edge server group 270 is located on a path that allows a client 210 to approach the service server 280, and if an edge server 260-1 or 260-n fails, the fault-tolerant edge server group 270-1, 270-m, 270-nm, and 270-n will replace the failed edge server, and other fault-tolerant edge servers 270-1, 270-m, 270-nm, and 270-n will replace the said fault-tolerant edge server. If an edge server or fault-tolerant edge server fails, the group includes a fault-tolerant edge server subgroup 275 consisting of more fault-tolerant edge servers 270-1 and 270-m than the number of the failed edge server or fault-tolerant edge server.

[0048] The fault-tolerant edge server group 270 is a set of fault-tolerant edge servers that are assigned for fault-inducing client retrieval when a client that was assigned to and used by a faulty edge server is reassigned to an edge server. Each fault-tolerant edge server can accept connections from one or more clients, and under normal circumstances, a fault-tolerant edge server is not assigned but is assigned when a client that was assigned to a faulty edge server requests edge server assignment by the fault occurrence check unit 240 of the client routing server 20.

[0049] When a fault-tolerant edge server actually performs fault recovery, the entire fault-tolerant edge server group 270 does not proceed; instead, the client routing server 20's edge server control unit 250 logically generates a fault-tolerant edge server subgroup via the fault-tolerant edge server subgroup control mechanism, and then assigns the fault-tolerant edge servers from the generated fault-tolerant edge server subgroup 275, which includes the fault-tolerant edge servers within it.

[0050] The fault-tolerant edge server subgroup 275 is a logically generated virtual fault-tolerant edge server group within the fault-tolerant edge server group 270. When an actual fault occurs in an edge server and fault-tolerant edge servers begin to respond, instead of assigning the entire fault-tolerant edge server group, the fault-tolerant edge server subgroup control mechanism of the edge server control unit 250 creates a virtual fault-tolerant edge server subgroup. It analyzes the number of clients already assigned to the faulty edge server and connection records, and, considering the number of fault-tolerant edge servers not assigned from the fault-tolerant edge server group, selects an appropriate number and assigns them to the virtual fault-tolerant edge server subgroup. After that, the subgroup is assigned to the fault-tolerant edge servers within the fault-tolerant edge server subgroup 275 generated via the edge server grouping assignment mechanism.

[0051] Once the incident response process is complete, the incident response edge server subgroup is deleted, and the incident response edge servers that were assigned to it are also left unassigned and remain in the incident response edge server group. Incident response edge server subgroups can be embodied by virtual groups that are created only when necessary during incident response to edge servers and deleted once completed.

[0052] The edge server and the fault-tolerance edge server are servers that control traffic between the client and the service server. They transmit connection information between the client 210 and the service server 280, system information of the edge server itself (CPU, memory, network, storage usage, utilization rate, etc.), and fault-related information to the client routing server 20. Under normal circumstances, the client connects to the service server 280 via the edge server. In the event of a fault, the client connects to the service server 280 via the fault-tolerance edge server. The edge server and the fault-tolerance edge server have the same configuration.

[0053] The client routing server 20 controls the communication path between the client and the service server so that it can proceed through edge servers, assigns edge servers and fault-response edge servers to client requests via DNS, receives communication-related information (connection, system status, traffic-related information) from edge servers and fault-response edge servers, checks whether a failure has occurred, and detects clients that are causing failures. The client routing server 20 also manages a blacklist of clients that are causing failures, blocks service server access in response to DNS requests from clients registered in the blacklist via DNS, and includes a DNS control unit 230, a failure occurrence check unit 240, and an edge server control unit 250. As a result, the client routing server 20 can also function as a client terminal connection control device that controls the connection of client terminals.

[0054] The DNS control unit 230 responds to DNS queries requested by client 100 by providing edge server IPs or fault-tolerant edge server IPs based on client IPs or user information. Specifically, it receives DNS requests from the client from the DNS server 220, requests edge server assignment from the client routing server 20, and then transmits the result from the edge server control unit 250 to the DNS server 220.

[0055] The fault occurrence check unit 240 checks for fault occurrences in the edge server and the fault response edge server, and receives communication-related information such as connection-related information, system status information, and traffic-related information from the edge server and the fault response edge server to confirm whether a fault has occurred in the relevant edge server (including the fault response edge server). Furthermore, if the fault occurrence check unit 240 determines that a fault has occurred in the relevant edge server (including the fault response edge server) according to the fault-related policy, it transmits the details to the edge server control unit 250.

[0056] The fault detection unit 240 can then check whether there is a fault in the edge server or fault-response edge server provided to the DNS control unit 230 by the edge server control unit 250 in response to the DNS query. If the provided edge server or fault-response edge server is not faulty, the DNS control unit 230 provides the provided edge server or fault-response edge server information to the client 210 via the DNS server 220.

[0057] Furthermore, the failure detection unit 240 can monitor failures of edge servers or fault-response edge servers regardless of DNS queries. When a failure occurs in an edge server or fault-response edge server, the edge server control unit 250 searches for client IP addresses or user information using the failed edge server or fault-response edge server and assigns the fault-response edge server IP address selected in the fault-response edge server group 270 to the searched client IP address or user information. At this time, when a client corresponding to the searched client IP address or user information requests a DNS query, the DNS control unit 230 can provide the fault-response edge server IP address assigned by the edge server control unit 250 to the searched client 100 via the DNS server 220. In addition, the DNS control unit 230 can provide the fault-response edge server IP address assigned by the edge server control unit 250 to the searched client 100 via the DNS server 220 regardless of DNS queries.

[0058] When an edge server or fault-response edge server fails, the edge server control unit 250 provides the fault-response edge server subgroup 275 selected from the fault-response edge server group 270 to the client in place of the faulty edge server or fault-response edge server. If there is only one client assigned to the fault-response edge server, the unit detects that single client as a fault-inducing client and comprises an edge server assignment unit 252, a fault-response edge server subgroup control unit 254, and a fault-inducing client detection unit 256.

[0059] When the edge server allocation unit 252 receives a DNS request from the client 210 via the DNS control unit 230, it allocates an edge server from the edge server group via the edge server grouping allocation mechanism. When the edge server allocation unit 252 detects a client causing a failure via the failure-causing client detection mechanism, it adds the client to a blacklist. After the failure-causing client is identified, it reassigns the client that was assigned to the failure-response edge server to an available edge server in the edge server group. If there is a DNS request from a client registered as blacklisted, it does not allocate an edge server or failure-response edge server.

[0060] When the fault response edge server subgroup control unit 254 receives a DNS request from the affected client after the fault occurrence check unit 240 has confirmed an edge server failure, it logically generates a fault response edge server subgroup 275 for locating the affected client within the fault response edge server group 270 via the fault response edge server subgroup control mechanism, assigns a fault response edge server to it, and then assigns the fault response edge server from the logically generated fault response edge server subgroup 275 via the edge server grouping assignment mechanism.

[0061] The fault-inducing client detection unit 256 analyzes the assignment status of the fault-responding edge server and the information of the relevant client via the fault-inducing client detection mechanism to find the fault-inducing client.

[0062] The client unit 210 may include agents 212 and 214 that send DNS queries containing user information to reconnect with a selected edge server from the group of edge servers when an edge server or fault-tolerance edge server fails. At this time, when the edge server control unit 250 receives DNS queries from the client's agents 212 and 214, it extracts user information from the client's DNS queries.

[0063] The client unit 210 consists of clients that connect to the service server 280, and may include clients on which agents are installed. The agents request information about the service server 280 from DNS, including the client's user information, receive information about edge servers or fault-response edge servers, and transmit this information to the client's internet application.

[0064] An edge server 260-1, 260-n or fault-tolerant edge servers 270-1, 270-m, 270-nm, 270-n according to one embodiment of the present invention connects a client 100 and a service server 280 and can be embodied by a program, server, and hardware equipment that has a service relay function, such as a proxy server or cache server, or a service function, and can be used as a service path to which a client connects and can also play the role of a service server to which a client connects.

[0065] Furthermore, the edge server group 260 and the fault-tolerant edge server group 270 can constitute a service relay network, which may consist of edge servers and fault-tolerant edge servers that have a service relay function or include the concept of servers or equipment with a service function, as well as network equipment such as gateways, routers, switches, and hubs.

[0066] Figure 3 is a flowchart showing a method for detecting fault-inducing clients using fault-response edge server grouping according to one embodiment of the present invention. A method for detecting fault-inducing clients using fault-response edge server grouping according to one embodiment will be described with reference to Figures 1 to 3.

[0067] First, in a service relay network 130 where multiple edge servers exist along the path that a client 210 takes to approach a service server 280, the fault occurrence check unit 240 checks for faults in the edge servers (step S310). If the fault occurrence check results in a fault occurring in an edge server, the edge server control unit 250 provides a fault-response edge server subgroup 275, consisting of more fault-response edge servers than the number of faulty edge servers selected from the fault-response edge server group 270, to clients connected to the faulty edge server in place of the faulty edge server (step S320).

[0068] Then the failure occurrence check unit 240 checks for failures in the failure-response edge servers provided to the client (step S330). If the failure occurrence check results in a failure occurring in the substitute failure-response edge server, the edge server control unit 250 provides the client with another failure-response edge server subgroup from the failure-response edge server group 270 that is not provided to the client (step S340). Here, the failure-response edge server subgroup 275 can consist of multiple failure-response edge servers based on the number of clients assigned to the failure-response edge server or failure-response edge server and connection records, when a failure occurs in an edge server or failure-response edge server, and the number of failure-response edge servers that were not assigned from the failure-response edge server group.

[0069] The fault occurrence check unit 240 checks for a fault response edge server failure provided to the client (step S350), and each time a fault occurs in a fault response edge server, the edge server control unit 250 generates a fault response edge server subgroup that is not provided to the client in the fault response edge server group 270, and acts as a substitute for the faulty fault response edge server. If there is only one client assigned to the faulty fault response edge server, the edge server control unit 250 detects that one client as the fault-inducing client (step S360).

[0070] The failure check of the edge server or fault-tolerance edge server can be performed by monitoring the failure of the edge server or fault-tolerance edge server when a DNS query is received from a client, or regardless of whether a DNS query is received from a client.

[0071] Figure 4 is a flowchart illustrating one embodiment in which, when a DNS query is received from a client, a failure is checked in the edge server or fault-tolerance edge server, and the faulty edge server or fault-tolerance edge server is replaced by a fault-tolerance edge server subgroup to detect the fault-inducing client. Referring to Figures 2 and 4, the DNS control unit 230 receives a DNS query from the DNS server 220 (step S410) and checks whether the received DNS query contains user information (step S415). If user information is present, the user information is retrieved (step S420).

[0072] In the edge server control unit 250, the edge server assignment unit 252 assigns an edge server IP corresponding to the extracted user information (step S430).

[0073] On the other hand, if the DNS query in step S415 does not contain user information, the edge server allocation unit 252 provides the edge server IP address assigned to the client that requested the DNS query (step S425).

[0074] Once an edge server IP address is assigned, the failure check unit 240 checks whether a failure has occurred in the assigned edge server (step S435).

[0075] If the fault occurrence check unit 240 checks for faults (S440) and no fault occurs, the edge server assignment unit 252 provides the assigned edge server IP or fault-responding edge server IP (step S445).

[0076] In the event of a failure, the system checks whether only one client is assigned to the edge server or fault-response edge server (step S450). If only one client is assigned to the edge server or fault-response edge server, that client is identified as the client that caused the failure (step S460). If multiple clients are assigned to the edge server or fault-response edge server, the failed edge server or fault-response edge server is replaced by a group of fault-response edge servers (step S455).

[0077] Figure 5 is a flowchart illustrating one embodiment of detecting a client that triggers a failure by checking whether an edge server or fault-tolerant edge server has failed, regardless of whether a DNS query has been received from a client, and replacing the failed edge server or fault-tolerant edge server with a fault-tolerant edge server subgroup. After replacing the failed edge server or fault-tolerant edge server with a fault-tolerant edge server subgroup, if a failure occurs in the edge server or fault-tolerant edge server, the system searches for the client IP address or user information using the failed edge server or fault-tolerant edge server, and upon receiving a DNS query request, it can provide the client with a fault-tolerant edge server selected from the fault-tolerant edge server group.

[0078] Referring to Figures 2 and 5, the failure check unit 240 monitors whether a failure occurs in the edge server or the fault response edge server, regardless of whether a DNS query has been received (step S510).

[0079] If the monitoring results indicate that a failure has occurred in the edge server or the fault-response edge server (step S520), the edge server control unit 250 searches for clients that are using the failed edge server or fault-response edge server as a route to access the service server 280 and stores the client information (step S530).

[0080] Next, it checks whether there is only one client assigned to the edge server or fault-tolerance edge server (step S540). If there is only one client assigned to the edge server or fault-tolerance edge server, that client is detected as the client that caused the failure (step S550). If there are multiple clients assigned to the edge server or fault-tolerance edge server, the faulty edge server or fault-tolerance edge server is replaced by a group of fault-tolerance edge servers (step S560).

[0081] Then, when a DNS query is received from the searched client (S570), the DNS control unit 230 provides the client that requested the DNS query with the assigned edge server IP or fault-tolerant edge server IP (step S580).

[0082] On the other hand, the client includes agents 212 and 214 that, when an edge server or fault-tolerance edge server fails, send DNS queries to connect to a fault-tolerance edge server selected from the fault-tolerance edge server group. Agents 212 and 214 can request DNS queries containing user information. The user information that may be included in the DNS query includes information that can identify the user or equipment, and may include at least one of the following: login ID, device ID (MAC, CPU ID, HDD serial, etc.), telephone number, and IP address.

[0083] When the edge server control unit 250 receives a DNS query from the client's agent, it can extract user information from the client's DNS query and provide the client with a fault-tolerance edge server IP address selected from the fault-tolerance edge server group that corresponds to the extracted user information.

[0084] On the other hand, the troubleshooting of a client that causes a failure using fault-responding edge server grouping according to one embodiment of the present invention will be described in more detail. First, in one embodiment of the present invention, edge server assignment can be performed as follows. Figure 6 shows the edge server assignment method according to one embodiment of the present invention. Referring to Figure 6, when client 610 requests information from service server 650 via DNS server 620, DNS server 620 transmits the DNS request from client 610 to client routing server 630. The edge server assignment unit (not shown) of client routing server 620 assigns the clients that make requests to the edge servers in the edge server group 640 it manages in order. First client 611 is assigned to edge server 1 641, client 2 612 to edge server 2 642, and client 3 613 to edge server 3 643, and so on. If there are more client requests than the number of edge servers in edge server group 640, the edge servers in the edge server group are reassigned from the beginning. If there are three edge servers in an edge server group, and clients 1-3 have already been assigned to edge servers 1-3, client 4 (614) will be reassigned to edge server 1 (641), and client 5 (615) will be assigned to edge server 2 (642). Clients that have already been assigned can continue to use their assigned edge servers without any changes. An edge server can accept one or more clients, and its maximum capacity is affected by the edge server's system performance.

[0085] Then, if an edge server fails after it has been assigned, the client causing the failure can be identified as follows. Figure 7 shows the case where client 1 611 becomes the client causing the failure due to malicious code or hacking. Referring to Figure 7, when edge server 1 641, to which clients 1, 4, and 7 are connected, is subjected to a traffic attack from client 1 611, edge server 1 611 becomes unstable, and edge server 1 641 transmits communication-related information such as system information, traffic information, and client connection information to the failure occurrence check unit (not shown) of client routing server 630, and the failure occurrence check unit (not shown) of client routing server 630 transmits the relevant information to the edge server control unit (not shown) of client routing server 630.

[0086] Figure 8 shows that clients 1, 4, and 7 connected to the under-attacked edge server 1641 are assigned to the fault-tolerant edge server subgroup 1810 in order to have the fault-tolerant edge server handle the situation. Referring to Figure 8, after confirming the number of clients (3) connected to the failed edge server 1641 via the fault-tolerant edge server subgroup control mechanism of the edge server control unit (not shown), the fault-tolerant edge server subgroup 1810 is logically created within the fault-tolerant edge server group (not shown), and fault-tolerant edge servers 1812 and 2814 are included in the fault-tolerant edge server subgroup 1810 and then assigned to it.

[0087] When clients 1 611, 4 614, and 7 617, which were assigned to edge server 1 641, request DNS requests to be assigned to an edge server again, the edge server assignment unit (not shown) of client routing server 630 assigns them to a disaster-response edge server in disaster-response edge server subgroup 1 810, which is not an edge server group. Here, we assume that disaster-response edge server subgroup 1 810 contains two disaster-response edge servers 812 and 814 (assuming that the disaster-response edge server subgroup 1 810 contains two disaster-response edge servers due to the disaster-response edge server subgroup control mechanism).

[0088] Since three clients (clients 1, 4, and 7) are assigned to edge server 1 641, clients 1 611 and 4 614 are assigned to fault-tolerance edge server 1 812, and client 7 617 is assigned to fault-tolerance edge server 1 812. Fault-tolerance edge server 1 812, to which clients 1 and 4 are connected, becomes unstable due to a traffic attack from client 1 611. Fault-tolerance edge server 1 812 transmits communication-related information to the fault occurrence check unit (not shown) of client routing server 630. The fault occurrence check unit (not shown) of client routing server 630 transmits the relevant information to the edge server control unit (not shown) of client routing server 630. At this point, the fault-inducing client detection mechanism within the edge server control unit of the client routing server reserves judgment because the fault-tolerance edge servers and clients are not yet assigned in a one-to-one ratio.

[0089] Subsequently, after isolating clients connected to disaster-response edge server 1 812 of the disaster-response edge server group 1 810 under attack, a new disaster-response edge server subgroup 2 910 is logically generated via the disaster-response edge server subgroup control mechanism of the edge server control unit (not shown), disaster-response edge servers 3 912 and 4 914 are included in disaster-response edge server subgroup 2 910, and then assigned to disaster-response edge server subgroup 2 910.

[0090] Figure 9 shows that clients 1 611 and 4 614 are separated and reassigned to fault-tolerant edge server subgroup 2 910. Referring to Figure 9, when clients 1 611 and 4 614, which were assigned to fault-tolerant edge server 1 812 in fault-tolerant edge server subgroup 1 810, make a DNS request to be reassigned to an edge server, the edge server assignment unit (not shown) of client routing server 630 assigns them to a fault-tolerant edge server in fault-tolerant edge server subgroup 2 910, which is not fault-tolerant edge server subgroup 1 810. Here, we assume that fault-tolerant edge server subgroup 2 910 contains two fault-tolerant edge servers 912 and 914 (assuming that the fault-tolerant edge server subgroup control mechanism has resulted in fault-tolerant edge server subgroup 2 containing two fault-tolerant edge servers).

[0091] Furthermore, client 7 617, which was connected to fault-response edge server 2 814 of fault-response edge server subgroup 1 810, is not a fault-inducing client, so it is assigned to edge server 4 644, which is a new edge server in the edge server group, by the edge server allocation section (not shown) of client routing server 630. It can be assigned to an available edge server, or to an already allocated edge server that has system capacity.

[0092] Since there are two clients (clients 1 and 4) assigned to fault-tolerance edge server 1 812 in fault-tolerance edge server subgroup 1 810, and there are also two fault-tolerance edge servers belonging to fault-tolerance edge server subgroup 2 910, client 1 611 is assigned to fault-tolerance edge server 3 912, and client 4 614 is assigned to fault-tolerance edge server 4 914. The edge server assignment unit (not shown) of client routing server 630 transmits the corresponding assignment information to the fault-inducing client detection unit (not shown) of client routing server 630. Fault-tolerance edge server 3 912, to which client 1 611 is connected, becomes unstable due to a traffic attack from client 1 611. The fault response edge server 3 912 transmits communication-related information to the fault occurrence check unit (not shown) of the client routing server 630, and the fault occurrence check unit (not shown) of the client routing server 630 transmits the relevant information to the edge server control unit (not shown) of the client routing server 630.

[0093] Figure 10 illustrates the process by which a client connected to a fault-tolerance edge server and attacking that fault-tolerance edge server is recognized as the fault-causing client. Referring to Figure 10, the fault-inducing client detection unit (not shown) of the client routing server 630 recognizes client 1611, which was connected to fault-tolerance edge server 1812, as the fault-causing client because the allocation ratio between fault-tolerance edge servers and clients is one to one, and fault-tolerance edge server 1812 has failed. The fault-inducing client detection unit (not shown) of the client routing server 630 records client 1611 in a blacklist and transmits this information to the edge server allocation unit (not shown) of the client routing server 630. The edge server allocation unit (not shown) of the client routing server 630 then determines that client 4614 is not a fault-causing client and can allocate it to edge server 4644, which has system capacity available among the edge servers in the edge server group.

[0094] Client 1 611, which is the cause of the failure and is blacklisted, will not be able to receive an edge server assignment, and will therefore be unable to connect to service server 650, even if it makes another DNS request to request information from service server 650. The edge server allocation unit (not shown) of client routing server 630 will respond with null without assigning an edge server.

[0095] On the other hand, the differences between the conventional fault-inducing client detection method utilizing a registered patented client routing system and the fault-inducing client detection method utilizing the grouping of fault-responding edge servers according to the present invention will be explained in more detail.

[0096] While there is little difference between the conventional patented method and the method of the present invention when a failure occurs in only one client, there are differences in detection method and accuracy when failures occur simultaneously in multiple clients. The present invention can accurately detect failure-inducing clients without false positives.

[0097] Figures 11 and 12 illustrate a fault-inducing client detection method utilizing a conventional registered patent client routing system. Figures 13 to 16 illustrate a fault-inducing client detection method utilizing grouping of fault-responding edge servers according to the present invention.

[0098] As described above in the background art of the present invention, referring to Figure 11, if we assume that a matrix 12 for identifying the client causing the failure is configured in a 3x2 matrix arrangement for an edge server group 11 consisting of 6 edge servers, it is configured as follows. When clients A to H are assigned edge servers as shown in the matrix, and clients A and F are the clients causing the failure, then edge servers 1, 2, 3, 4, and 6 in the edge server group will experience failures due to clients A and F.

[0099] However, as seen from the matrix in Figure 12, not only clients A and F, but also other clients assigned to edge servers 1, 2, 3, 4, and 6, which experienced failures in the edge server group, are also designated as failure-inducing clients. This leads to the problem that clients B and E are also recognized as failure-causing clients. In other words, clients B and E can be mistakenly identified as failure-inducing clients.

[0100] On the other hand, to explain the fault-inducing client detection method using fault-responding edge server grouping according to the present invention in comparison with the conventional method, we assume that there are clients A to H, the same as in the metrics method, and that as shown in Figure 13, there are two edge servers 1 and 2 in the edge server group 13 for grouping, and nine fault-responding edge servers 11 to 19 in the fault-responding edge server group 14.

[0101] Referring to Figure 14, since there are only two edge servers in the edge server group, clients A to H are assigned edge servers to perform services as shown in Figure 14. If clients A and F are failure-inducing clients, then both edge servers 1 and 2 in edge server group 13 will fail.

[0102] The Edge Server Control Unit (not shown) first generates two subgroups, Subgroup 1 and Subgroup 2, within the Edge Server Control Unit through its fault-tolerant Edge Server Subgroup Control Mechanism and Edge Server Grouping Assignment Mechanism. Subgroup 1 includes fault-tolerant Edge Servers 11 and 12, while Subgroup 2 includes fault-tolerant Edge Servers 13 and 14. Clients A through H, which were assigned to the faulty Edge Servers 1 and 2, are then assigned to Subgroups 1 and 2, as shown in Figure 15.

[0103] Referring to Figure 15, since Client A and Client F, the clients causing the failure, were assigned to the fault-response edge server 11 of fault-response edge server subgroup 1 13-1 and fault-response edge server 13 of fault-response edge server subgroup 2 13-2, the corresponding fault-response edge servers will start to fail.

[0104] The fault-tolerant edge server subgroup control mechanism and edge server grouping assignment mechanism of the edge server control unit (not shown) generate fault-tolerant edge server subgroups 3 13-3 and 4 13-4. As shown in Figure 16, fault-tolerant edge servers that were not assigned are included in fault-tolerant edge server subgroup 3 13-3 (15 and 16) and fault-tolerant edge servers 17 and 18 (17 and 18) in fault-tolerant edge server subgroup 4 13-4, and clients A, B, E, and F connected to the fault-tolerant edge servers 11 and 13 that experienced failures are assigned to these subgroups.

[0105] Referring to Figure 16, since the fault-responding edge server 15 of fault-responding edge server subgroup 3 13-3 and the fault-responding edge server 18 of fault-responding edge server subgroup 4 13-4 have both experienced failures, and there is a one-to-one mapping between clients and fault-responding edge servers, client A assigned to fault-responding edge server 15 and client F assigned to fault-responding edge server 18 are identified as clients causing the failure. In summary, the method of the present invention detects only A and F as fault-inducing clients, and does not detect clients B and E, which were incorrectly detected by the conventional method, as fault-inducing clients.

[0106] Hereinafter, with reference to Figure 17, a method will be described in which a client terminal connection control device according to one embodiment performs client terminal connection control using the fault-inducing client detection method described above. The client terminal connection control device may include a communication unit that communicates data with at least one of the client terminal, edge server, and fault-responding edge server, and a processor for performing the following processing.

[0107] First, the client terminal connection control device can assign the communication processing of a first client group, which consists of multiple client terminals, to an edge server (S1710). Next, if a failure occurs in the operation of the edge server, the client terminal connection control device can assign the communication processing of a second client group, which includes at least one client terminal belonging to the first client group, to a fault-responding edge server (S1720). Here, the second client group can be configured to include only at least one client terminal belonging to the first client group. Alternatively, the second client group can be configured to include other client terminals in addition to at least one client terminal belonging to the first client group.

[0108] Next, the client terminal connection control device can determine whether a failure occurs in the operation of the fault-tolerant edge server (S1730). The client terminal connection control device can control the connection of client terminals depending on whether a failure has occurred. For example, if a failure occurs in the operation of the fault-tolerant edge server and the number of client terminals assigned to the fault-tolerant edge server is greater than or equal to a predetermined number, the client terminal connection control device can assign the communication processing of a sub-client group, which includes at least one client terminal belonging to the client group assigned to the fault-tolerant edge server, to the fault-tolerant edge server. For example, the client terminal connection control device can assign the communication processing of the sub-client group to a fault-tolerant edge server that is not experiencing a failure. Here, the predetermined number may be one or two, or any other arbitrary setting value.

[0109] More specifically, the client terminal connection control device can generate a sub-client group that includes at least one client terminal belonging to a client group assigned to the fault-tolerance edge server, and assign the communication processing of the generated sub-client group to the fault-tolerance edge server. As mentioned above, the sub-client group can be configured to include only at least one client terminal belonging to a client group assigned to the fault-tolerance edge server that has experienced a failure. Alternatively, the sub-client group can be configured to include other client terminals in addition to at least one client terminal belonging to a client group assigned to the fault-tolerance edge server that has experienced a failure.

[0110] On the other hand, if a failure occurs in the operation of the fault response edge server, and the number of client terminals assigned to the fault response edge server is predetermined, the client terminal connection control device can determine that predetermined number of client terminals as fault-inducing client terminals.

[0111] The following describes a method by which a client terminal connection control system according to one embodiment performs client terminal connection control using the fault-inducing client detection method described above, with reference to Figure 18. The client terminal connection control system can be configured to include an edge server, a fault-responding edge server, and a connection control device.

[0112] First, the edge server can perform communication processing for a first client group consisting of multiple client terminals (S1810). Next, if a failure occurs in the operation of the edge server, the fault-responding edge server can perform communication processing for a second client group, which includes at least one client terminal belonging to the first client group (S1820).

[0113] Next, the connection control device can determine whether a failure occurs in the operation of the fault-tolerant edge server (S1830). Subsequently, the connection control device can control the connection of client terminals depending on whether a failure has occurred. For example, if a failure occurs in the operation of the fault-tolerant edge server and a predetermined number of client terminals have been assigned to the fault-tolerant edge server, the connection control device can assign the communication processing of a sub-client group, which includes at least one client terminal belonging to the client group assigned to the fault-tolerant edge server, to the fault-tolerant edge server. For example, the connection control device can assign the communication processing of the sub-client group to a fault-tolerant edge server that is not experiencing a failure. Here, the predetermined number may be one or two, or any other arbitrary setting value.

[0114] On the other hand, if a failure occurs in the operation of the fault response edge server, and the number of client terminals assigned to the fault response edge server is predetermined, the connection control device can determine that predetermined number of client terminals as fault-inducing client terminals.

[0115] The methods, apparatus, and systems according to the embodiments described above can be embodied as program code readable by a computer (including all devices having information processing functions) on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices that store data readable by a computer system. Examples of computer-readable recording devices include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage devices, and the like.

[0116] Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely illustrative, and a person with ordinary skill in the art should understand that a variety of modifications and equivalent other embodiments are possible. Therefore, the true scope of technical protection of the present invention should be determined by the technical idea of ​​the appended claims. [Industrial applicability]

[0117] This disclosure can be used to detect clients that cause network failures. [Explanation of symbols]

[0118] 100 Client Department 102, 104 Clients 14 Agents 110 DNS Server 120 Client routing server 130 Service relay network 132 Edge Server Groups 134. Fault-Responding Edge Server Group 140 Service Servers 20 Client routing servers 210 clients 210-1 Client 1 212 Agents 201-n Client n 124 Agents 220 DNS servers 230 DNS Control Unit 240 Fault Occurrence Check Unit 250 Edge Server Control Unit 252 Edge Server Allocation Section 254 Fault Response Edge Server Subgroup Control Unit 256 Fault-inducing client detection unit 260 Edge Server Groups 260-1 Edge Server 1 260-n edge server n 270 Edge Server Group for Fault Response 275. Fault Response Edge Server Subgroup 270-1 Fault-Responding Edge Server 1 270-m Fault-tolerant Edge Server m 270-nm fault-tolerant edge server nm 270-n Fault-tolerant Edge Server n 610 clients 611 Client 1 612 Client 2 613 Client 3 614 Client 4 615 Client 5 620 DNS servers 630 Client routing server 640 Edge Server Groups 641 Edge Server 1 642 Edge Server 2 643 Edge Server 3 644 Edge Server 4 650 Service Servers 810 Fault-Responding Edge Server Subgroup 1 812 Edge Server 1 (Fault Response) 814 Edge Server 2 for Fault Response 910 Fault Response Edge Server Subgroup 2 912 Fault-Responding Edge Server 3 914 Edge Server 4 for troubleshooting 11 Edge Server Groups 12 Edge Server Allocation Matrix 13 Edge Server Groups 14. Fault-Responding Edge Server Group 13-1 Incident Response Edge Server Subgroup 1 13-2 Edge Server Subgroup 2 for Disaster Response 13-3 Edge Server Subgroup 3 for Disaster Response 13-4 Edge Server Subgroup 4 (Fault Response)

Claims

1. A client terminal access control method executed by a client terminal access control device, Assigning communication processing for a first client group, which has multiple client terminals, to the server, If a failure occurs in the operation of the server, a first failure response server subgroup is created, and the communication processing of a second client group, which has at least one client terminal belonging to the first client group, is assigned to the first failure response server of the first failure response server subgroup. To determine whether or not a failure has occurred in the operation of the first fault response server, If a failure occurs in the operation of the first fault response server, the system will determine whether to proceed with the first process or the second process based on the number of client terminals assigned to the first fault response server. Equipped with, Based on the fact that the number of client terminals assigned to the first fault response server is 1, it is decided to proceed with the first process. Based on the fact that the number of client terminals assigned to the first fault response server is greater than 1, it is decided to proceed with the second process. The first process described above is to determine the client terminal assigned to the first fault response server as the client terminal that has experienced a failure. The second process described above is the process of generating a second fault response server subgroup and assigning the communication processing of a subclient group, which has at least one client terminal assigned to the first fault response server, to the second fault response server of the second fault response server subgroup. The number of client terminals assigned to the second fault response server is less than the number of client terminals assigned to the first fault response server. A method wherein, if no failure occurs in the operation of the first fault response server, the client terminal assigned to the first fault response server is assigned to a server to which client terminals can be assigned.

2. A client terminal access control device, A communication unit configured to perform data communication with a server, a first fault response server, and a second fault response server, Assigning communication processing for a first client group, which has multiple client terminals, to the server, If a failure occurs in the operation of the server, a first failure response server subgroup is created, and the communication processing of a second client group, which has at least one client terminal belonging to the first client group, is assigned to the first failure response server of the first failure response server subgroup. To determine whether or not a failure has occurred in the operation of the first fault response server, If a failure occurs in the operation of the first fault response server, the system will determine whether to proceed with the first process or the second process based on the number of client terminals assigned to the first fault response server. A processor configured to perform the following: Equipped with, Based on the fact that the number of client terminals assigned to the first fault response server is 1, it is decided to proceed with the first process. Based on the fact that the number of client terminals assigned to the first fault response server is greater than 1, it is decided to proceed with the second process. The first process described above is to determine the client terminal assigned to the first fault response server as the client terminal that has experienced a failure. The second process described above is the process of generating a second fault response server subgroup and assigning the communication processing of a subclient group, which has at least one client terminal assigned to the first fault response server, to the second fault response server of the second fault response server subgroup. The number of client terminals assigned to the second fault response server is less than the number of client terminals assigned to the first fault response server. If no failure occurs in the operation of the first fault response server, the client terminal assigned to the first fault response server is assigned to a server capable of assigning client terminals, in a device.

3. A client terminal access control method performed by a client terminal access control system having a server, a first fault response server, a second fault response server, and an access control device, The communication processing for a first client group comprising multiple client terminals is performed by the server, If a failure occurs in the operation of the server, the access control device generates a first failure response server subgroup, and the first failure response server of the first failure response server subgroup executes the communication processing of a second client group, which includes at least one client terminal belonging to the first client group. The access control device determines whether or not a failure has occurred in the operation of the first fault response server, If a failure occurs in the operation of the first fault response server, the access control device will determine whether to proceed with the first process or the second process based on the number of client terminals assigned to the first fault response server. Equipped with, Based on the fact that the number of client terminals assigned to the first fault response server is 1, it is decided to proceed with the first process. Based on the fact that the number of client terminals assigned to the first fault response server is greater than 1, it is decided to proceed with the second process. The first process described above is to determine the client terminal assigned to the first fault response server as the client terminal that has experienced a failure. The second process is the process of generating a second fault response server subgroup and assigning the communication processing of a subclient group, which has at least one client terminal assigned to the first fault response server, to the second fault response server of the second fault response server subgroup. The number of client terminals assigned to the second fault response server is less than the number of client terminals assigned to the first fault response server. A method wherein, if no failure occurs in the operation of the first fault response server, the client terminal assigned to the first fault response server is assigned to a server to which client terminals can be assigned.

4. A client terminal access control system, Server and The first fault response server, The second fault response server, Access control device, Equipped with, The aforementioned server, Executes communication processing for a first client group consisting of multiple client terminals. If a failure occurs in the operation of the server, the access control device generates a first failure response server subgroup, and the first failure response server of the first failure response server subgroup executes communication processing for a second client group which has at least one client terminal belonging to the first client group. The access control device determines whether or not a failure has occurred in the operation of the first fault response server. If a failure occurs in the operation of the first fault response server, the access control device decides whether to proceed with the first process or the second process based on the number of client terminals assigned to the first fault response server. Based on the fact that the number of client terminals assigned to the first fault response server is 1, it is decided to proceed with the first process. Based on the fact that the number of client terminals assigned to the first fault response server is greater than 1, it is decided to proceed with the second process. The first process described above is to determine the client terminal assigned to the first fault response server as the client terminal that has experienced a failure. The second process is the process of generating a second fault response server subgroup and assigning the communication processing of a subclient group, which has at least one client terminal assigned to the first fault response server, to the second fault response server of the second fault response server subgroup. The number of client terminals assigned to the second fault response server is less than the number of client terminals assigned to the first fault response server. If no failure occurs in the operation of the first fault response server, the client terminal assigned to the first fault response server is assigned to a server capable of assigning client terminals, in a system.

5. A computer program stored on a computer-readable recording medium for performing the method described in any one of claims 1 and 3.

6. A computer-readable recording medium storing a computer program for performing the method described in any one of claims 1 and 3 by a computer.

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