A fault-tolerant method for displaying business information in a centralized dispatching system

Abstract

The present invention discloses a fault-tolerant method for displaying business information in a centralized dispatching system, which can restore the display business information of a current communication node through copies of the display business information of other communication nodes, so as to achieve the effect of completely consistent display business data among multiple communication nodes, ensure data consistency, and prevent invalid data from having a negative impact on train dispatching and command work.

Description

Technical Field

[0001] The invention relates to the technical field of railway transportation, and in particular to a fault-tolerant method for displaying business information in a centralized dispatching system. Background Art

[0002] The TCPIP protocol is a network communication specification for information transmission between different types of network devices. According to the TCPIP protocol, the address and port information of the network device are first created as a socket, and then the byte stream transmission is started. After the transmission is completed, the device resources are released through the socket. When the network device acts as a server to transmit byte streams to multiple clients, multiple sockets need to be created. The TCP / IP protocol ensures the reliability of the connection channel by initiating a handshake process from the client to the server at the transport layer.

[0003] The centralized scheduling system is a distributed hard real-time system built on the basis of TCPIP protocol. Different network devices transmit byte streams through Socket sockets, and then parse the data through application layer protocol as the basis for executing business logic.

[0004] The centralized scheduling system transmits byte streams through Sockets. The byte streams contain specific business data, and the data format is specified by the application layer protocol. If the data contained in the byte stream exceeds the valid range specified by the communication protocol, or there is data that causes the TCPIP application to be forcibly closed, the data will be determined as invalid data by the communication module of the centralized scheduling system.

[0005] Once invalid data is detected, the communication module will refuse to process the current byte stream data and record the error status as a log, the communication buffer storing the byte stream will be cleared, and the socket of the communication module returns to the closed state. When the transmitted byte stream contains invalid data, the existing technology can prevent the scheduling centralized system from crashing or failing as a whole.

[0006] Although the communication module designed according to the prior art can prevent the system from crashing or failing as a whole, it cannot completely avoid the deviation between the system status and the design expectation. Taking the display service of station representation information and operation diagram phase plan as an example, the byte stream of this type of information is processed by the server and transmitted to multiple display terminals. The design expectation is that the display content of multiple display terminals is consistent. However, when a communication node or data link fails, the subsequent display service process is forced to be interrupted because the communication module refuses to process invalid data, and the display content of the display terminal that receives invalid data and valid data will deviate. The deviation of the station equipment status and the operation diagram phase plan status displayed by different display terminals will make it impossible for multiple train dispatchers to reach a consensus on the real dispatching scenarios within their jurisdiction, thereby seriously interfering with the normal process of train dispatching and command. Summary of the invention

[0007] The purpose of the present invention is to provide a fault-tolerant method for displaying service information in a centralized scheduling system, which can achieve the effect of completely consistent display service data among multiple communication nodes when invalid data exists in the transmitted byte stream.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] A fault-tolerant method for displaying business information in a centralized scheduling system, comprising:

[0010] After each display terminal receives the same display service information sent by the server host, it determines whether the display service information it receives is valid data;

[0011] If the current display terminal determines that the display business information it has received is invalid data, it generates request information based on the index of the corresponding display business information to request a copy of the corresponding display business information from the preset data backup node and the server backup machine, and verifies the received copy. If the verification passes, the corresponding display business information is restored using the received copy; wherein the preset data backup nodes are several display terminals.

[0012] It can be seen from the technical solution provided by the present invention that the display business information of the current communication node can be restored through the display business information copies of other communication nodes, so as to achieve the effect of complete consistency of display business data among multiple communication nodes, ensure data consistency, and prevent invalid data from having a negative impact on train dispatching and command work. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0014] Figure 1 A flowchart of a fault-tolerant method for displaying service information in a centralized scheduling system provided by an embodiment of the present invention;

[0015] Figure 2 A schematic diagram of a display service information transmission method of a centralized scheduling system provided in an embodiment of the present invention;

[0016] Figure 3 A schematic diagram of a communication buffer of a display terminal provided in an embodiment of the present invention;

[0017] Figure 4 A schematic diagram of a formalized model of a single communication node provided in an embodiment of the present invention;

[0018] Figure 5 A schematic diagram of a formalized model of multiple communication nodes provided by an embodiment of the present invention;

[0019] Figure 6 The overall flow chart of the display service information provided by the embodiment of the present invention when it does not contain invalid data;

[0020] Figure 7 The overall flow chart of the display service information provided by the embodiment of the present invention when it contains a single invalid data;

[0021] Figure 8 The present invention provides an overall flow chart of the display service information when it contains multiple invalid data. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0023] First, the terms that may be used in this article are explained as follows:

[0024] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0025] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0026] The following is a detailed description of a fault-tolerant method for displaying service information in a centralized scheduling system provided by the present invention. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professional and technical personnel in the field. If no specific conditions are specified in the embodiments of the present invention, the conventional conditions in the field or the conditions recommended by the manufacturer shall be followed.

[0027] like Figure 1 As shown, a fault-tolerant method for displaying business information in a centralized scheduling system mainly includes the following steps:

[0028] After each display terminal receives the same display service information sent by the server host, it determines whether the display service information it receives is valid data;

[0029] If the current display terminal determines that the display business information it has received is invalid data, it generates request information based on the index of the corresponding display business information to request a copy of the corresponding display business information from the preset data backup node and the server backup machine, and verifies the received copy. If the verification passes, the corresponding display business information is restored using the received copy; wherein the preset data backup nodes are several display terminals.

[0030] The above scheme of the embodiment of the present invention can restore the display business information of the current communication node through the display business information copies of other communication nodes, so as to achieve the effect of complete consistency of display business data among multiple communication nodes, ensure data consistency, and prevent invalid data from having a negative impact on train dispatching and command work.

[0031] For ease of understanding, the main working principles of the embodiment of the present invention and the formalized model of the method for displaying service information fault tolerance are introduced in detail below.

[0032] The transmission mode of display service information of the centralized dispatching system can be summarized as follows: Figure 2 As shown, Figure 2 The server and display terminal in the figure represent different types of communication nodes, and the connecting line represents the transmission path of the byte stream. Figure 2The number of display terminals is only an example. The server host is responsible for receiving and sending display service information and can send display service information to each display terminal. The server standby only sends heartbeat data to the communication node with a connection, indicating that there is a standby in the network. The display terminal can create a socket to connect to the server host and the server standby to perform byte stream reception and transmission operations.

[0033] Figure 2 The byte stream in the network is the carrier of display business information. The various fields of display business information are defined by the Dispatching Central System Data Communication Protocol. The Dispatching Central System Data Communication Protocol is a TCPIP application layer protocol that defines the method of reading and writing byte streams in the network. According to the protocol, the first 31 bytes of the byte stream contain length, time, protocol version number, source parameter, destination parameter, information type code and reserved field.

[0034] The part after the byte stream contains the specific content of the display service information. Each data σ in the display service information is defined as σ=(d,e S ,e E ,o), where d is the MD5 value of the entire business information, and the offset e S is the starting byte of data σ in the communication buffer, offset e E is the end byte occupied by data σ in the communication buffer, and o is the data content of the display business information.

[0035] When the server host sends the same display service information to multiple terminals, the data σ will have corresponding copies σ' in the cache lists of other communication nodes. Figure 3 For example, σ1 is the data obtained by displaying terminal A reading the byte stream at time t1, and the first byte occupied in the communication buffer is the offset e S , the last byte is offset e E The communication caches of display terminal A and display terminal B read the byte stream sent by the server at time t1 and t3, t0 and t2, respectively, and their MD5 calculation results are hash values ​​d1 and d3, d0 and d1, respectively. Since the MD5 algorithm is unforgeable, the same MD5 values ​​of the display service information at time t1 and t2 indicate that the server sent the same display service information to display terminal A and display terminal B, and loaded it into the communication cache at time t1 and t2, respectively. Since the content of the display service information is exactly the same, at time t2, the communication cache of display terminal B has the same byte stream as e. S Bytes to e EThe data σ1' corresponding to the bytes is completely consistent with the content o1' and o1 of σ1, and σ'1 is a copy of σ1. After the data σ1 becomes invalid due to a communication node or data link failure, the original data content o1 can be restored by obtaining the copy σ'1 stored in other communication nodes.

[0036] Figure 2 The behavior of a single communication node in the network can be formally modeled as Figure 4 Flowchart shown. Figure 4 In the example, a single communication node model consists of business logic and communication module. If the communication node is a server, the business logic is data forwarding; if the communication node is a display terminal, the business logic is graphic display. The communication modules of the server and the display terminal are composed of communication cache, fault tolerance list and cache list. The communication cache is used to receive and send byte streams. The fault tolerance list and cache list can store multiple byte streams received by the communication node. If the received byte stream contains invalid data, the communication node stores the byte stream in the fault tolerance list. If the received byte stream does not contain invalid data, the communication node stores the byte stream in the cache list. The fault tolerance list and cache list will record the MD5 value of the byte stream while storing the byte stream, which serves as an index to facilitate the communication module to find data. The communication module can transmit the byte streams in the communication cache, fault tolerance list and cache list to the business logic through the push mechanism to perform further data forwarding or graphic display operations. To prevent data backlog, each byte stream stored in the fault tolerance list and cache list will be deleted after 300 seconds of storage.

[0037] Figure 4 In the formal model shown, the behavior of a single communication node can be specifically stated as:

[0038] ① The byte stream received by the communication cache does not contain invalid data. The communication node copies the byte stream and stores it in the cache list, and executes behavior ⑤ to transmit the byte stream to the business logic. After the execution is completed, the communication node executes behavior ⑩.

[0039] ② The communication node executes behavior ⑩, writes the byte stream given by the communication node information processing logic into the communication cache, and sends it to other communication nodes.

[0040] ③The byte stream received by the communication buffer contains invalid dataσ F ,The communication node copies and stores the byte stream into the fault-tolerant list.

[0041] ④If the replaced byte stream no longer contains other invalid data, the communication node moves the byte stream to the cache list.

[0042] ⑤ The communication node transmits the byte stream newly added to the cache list to the business logic through the push mechanism.

[0043] ⑥The communication node finds the copy σ' in the cache list F After that, execute behavior ⑩ and copy σ' F Write to the communication buffer and send to other communication nodes.

[0044] ⑦ The communication node executes action ⑩ and sends a copy σ' to the network F Request information.

[0045] ⑧The communication node deletes the byte stream that has been stored in the fault-tolerant list for more than 300 seconds.

[0046] ⑨ The communication node deletes the byte streams in the cache list that have been stored for more than 300 seconds.

[0047] ⑩ The communication node clears the communication buffer and prepares to receive or send the next byte stream.

[0048] When there is no invalid data in the network, the communication node executes ① and ⑤ to receive data and executes ② to send data. F After that, the communication node can interact with multiple nodes through specific messages to obtain invalid data from the network. F A copy of σ' F The message interaction process is completed by multiple communication nodes in collaboration, which can be generally expressed as Figure 5 The formal model shown.

[0049] Figure 5 In the example, s0 and s1 represent the server host and server standby respectively, and c0, c1, c2, and c3 are Figure 2 4 display terminals in the network. The server host s0 sends the same display business information to the server backup s1 and terminals c0, c1, c2, and c3. Different display terminals can establish data links through the server backup and communicate with each other. The server backup can set up specific data backup nodes according to the display terminal that initiates the request message. In the figure, display terminal c0 initiates a request message to find an invalid data copy, and display terminals c1, c2, and c3 act as data backup nodes to verify the request message. Of course, if display terminal c1 initiates a request message to find an invalid data copy, the server backup will set display terminals c0, c2, and c3 as data backup nodes to verify the request message. The centralized scheduling system is built on a private network that is closed to the outside world. Each server or terminal device uses a fixed signature within the network to uniquely indicate the source of the message. The signature is formed by a combination of the device type, device code, port number, and IP address of the communication node. The signatures of s0, s1, c0, c1, c2, and c3 are respectively denoted as Each communication node stores the signatures of all nodes in the network to verify the legitimacy of the message source. The behaviors of multiple communication nodes in the formal model can be divided into five stages: (i) triggering stage, (ii) request stage, (iii) verification stage, (iv) statistics stage, and (v) receipt stage. The information fault-tolerant method uses the reserved field in the first 31 bytes of the data communication protocol of the scheduling centralized system to additionally store the MD5 code and the statistical code u1, which are used as the uniqueness criterion of the byte stream and the counting basis of the statistical stage, respectively. The statistical code u1 is managed by the server standby s1, with a length of 1 byte, a maximum value of 255, and an initial value of 0. The server standby s1 increases by 1 each time a request is executed, and resets to 0 after reaching the maximum value.

[0050] The main processes of the above five stages are as follows:

[0051] (i) Triggering stage.

[0052] See also Figure 1 In the flowchart shown, after each display terminal receives the same display service information sent by the server host, it determines whether the display service information it receives is valid data. It is in the triggering stage of the display service information fault tolerance method. The process of the triggering stage includes: receiving the display service information sent by the server host; using the source parameter extracted from the display service information to determine whether the source of the information is legal; if the source of the information is legal, extracting the verification information from the display service information, and judging whether the display service information is valid data based on the verification information. Among them, judging whether the display service information received by itself is valid data includes: extracting the data content of the display service information and the corresponding MD5 value from the byte stream of the display service information, calculating the MD5 value of the data content of the display service information, and comparing it with the extracted MD5 value; if they are consistent, it is valid data; if they are inconsistent, it is invalid data.

[0053] Combination Figure 5 The formal model shown, the process of the triggering phase can be described as:

[0054] Server host s0 will display business information Sent to display terminal c0, display terminal c0 loads the communication buffer and reads the data. DISP is the display service information tag. After the communication buffer is loaded with the byte stream, display terminal c0 will perform the following operations:

[0055] 1) Extract the source parameters from the first 31 bytes. The parameters include device type, device code, port number and IP address, combine them into a signature and verify the legitimacy of the message source.

[0056] 2) If the source of the message is legitimate, display terminal c0 from Extract the MD5 code d T, take out the display service information m from the following bytes T , and then calculate the MD5 code of the entire displayed business information. If the message source is illegal, the display terminal c0 stops reading the byte stream and executes action ⑩.

[0057] 3) If the MD5 code of the displayed business information is equal to d T , it can be determined that the byte stream received by the communication buffer does not contain invalid data σ F , display terminal c0 will exit the trigger process, and then execute actions ① and ⑤ to receive data normally.

[0058] 4) If the MD5 code of the displayed business information is not equal to d T , it can be determined that the byte stream received by the communication buffer contains invalid data σ F , the display terminal c0 will detect invalid data σ while reading the communication buffer F The starting byte occupied in the communication buffer End Byte And the data content F , σ F Can be expressed as a four-tuple If no specific location of invalid data is detected, then Marked as byte stream header, Marks the end of the byte stream, o F The data content is the entire byte stream. Display terminal c0 detects invalid data σ F After that, actions ③ and ⑦ will be executed. The information fault-tolerant method enters the request phase.

[0059] (ii) Request stage:

[0060] See also Figure 1 The flowchart shown, wherein if the current display terminal determines that the display business information it has received is invalid data, then a request message is generated according to the index of the corresponding display business information to request a copy of the corresponding display business information from the preset data backup node and the server standby machine in the request phase of the display business information fault-tolerant method, and the process of the request phase includes: the current display terminal generates a request message for a copy of the corresponding display business information according to the index of the corresponding display business information, and sends it to the server standby machine; the server standby machine extracts the source parameter from the request message to determine whether the source of the information is legal; if the source of the information is legal, the value of the statistical code is increased by 1, and combined with the index extracted from the request message, verification information is constructed, and then the verification information is sent to the preset data backup node.

[0061] Combination Figure 5 The formal model shown, the process of the request phase can be described as:

[0062] Display terminal c0 sends a copy σ' to server standby s1 F Request Information Server standby s1 loads the communication buffer and reads the data. REQ is the request information tag. After the communication buffer is loaded with the byte stream, server standby s1 will perform the following operations:

[0063] 1) Extract the source parameters from the first 31 bytes. The parameters include device type, device code, port number and IP address, combine them into a signature and verify the legitimacy of the message source.

[0064] 2) If the source of the message is illegal, the server standby s1 stops reading the byte stream and executes action ⑩.

[0065] 3) If the source of the message is legitimate, the value of u1 is increased by 1. Extract the MD5 code d T , extract the starting byte from the following bytes and end byte Then get the current statistical code u1 to form a copy σ' F Verification information Then send it to the data backup node c pre-set by the server backup machine s1 i (i∈{1,2,3}), after sending, the information fault tolerance method enters the verification phase of the u1th replica request. VER is the verification information label.

[0066] (iii) Verification phase:

[0067] In an embodiment of the present invention, after the verification information is sent to the preset data backup node, the verification phase of the display business information fault-tolerant method is entered, and the process of the verification phase includes: the server standby machine uses the index to search the local cache list for a byte stream with the same index; if so, it means that there is a copy of the corresponding display business information in the server standby machine cache list, and the server standby machine passes the verification; after each data backup node receives the verification information, it extracts the source parameter from it to determine whether the source of the information is legal; if the source of the information is legal, it extracts the index from the verification information and searches the local cache list for a byte stream with the same index; if so, it means that there is a copy of the corresponding display business information in the preset data backup node cache list, and the preset data backup node passes the verification; the data backup node that passes the verification extracts the index and statistical code from the verification information, constructs statistical information, and transmits it to other data backup nodes and the server standby machine.

[0068] Combination Figure 5 The formal model shown, the process of the verification phase can be described as:

[0069] Server backup machine s1 sends data to data backup node ci (i∈{1,2,3}) sends a copy σ' F Verification information Data backup node c i (i∈{1,2,3}) loads the communication cache and reads the data. After the communication cache loads the byte stream, the data backup node c i (i∈{1,2,3}) or server standby s1 will perform the following operations:

[0070] 1) Server standby s1 searches for the MD5 code d in the cache list T If a byte stream is found, the data σ exists in the cache list. F A copy of σ' F , the verification of the s1 node passes. If the byte stream is not found, the verification of the s1 node fails. If the server standby s1 fails the verification, it will exit the verification phase of the u1-th replica request and execute action ⑩. After the server standby exits the verification phase, it will still forward the verification information to the data backup node.

[0071] 2) Extract the source parameters from the first 31 bytes. The parameters include the device type, device code, port number and IP address, combine them into a signature and verify the legitimacy of the message source.

[0072] 3) If the source of the message is illegal, the data backup node c i (i∈{1,2,3}) stops reading the byte stream and executes behavior ⑩.

[0073] 4) If the source of the message is legitimate, data backup node c i (i∈{1,2,3}) from Extract the MD5 code d T .

[0074] 5) Data backup node c i (i∈{1,2,3}) Search the cache list for the MD5 code d T If a byte stream is found, the data σ exists in the cache list. F A copy of σ' F , c i The verification of the (i∈{1,2,3}) node passes. If no byte stream is found, then c i The verification of the node (i∈{1,2,3}) fails, c i (i∈{1,2,3}) is a failed node. Data backup node c i If (i∈{1,2,3}) fails the verification, it will exit the verification phase of the u1th replica request and execute action ⑩.

[0075] exist Figure 5In the example, the failed node c2 that exits the verification phase is marked as X.

[0076] 6) If the data backup node c i (i∈{1,2,3}) is verified, then the replica σ' F Verification information Take out the statistical code u1 and the starting byte and end byte Composition copy σ' F Statistics STA is a statistical information tag. The node executes behavior ⑥ and sends it to other data backup nodes and server standby s1. The information fault tolerance method enters the statistical phase of the u1-th replica request.

[0077] In the embodiment of the present invention, the data backup node that passes the verification will send statistical information to other data backup nodes and server backup machines. If other data backup nodes or server backup machines fail to pass the verification and exit the verification process, they will not perform further processing after receiving the statistical information.

[0078] (iv) Statistical stage.

[0079] In an embodiment of the present invention, after the verified data backup node transmits the statistical information to other data backup nodes and the server standby machine, it enters the statistical phase of the display business information fault-tolerant method; the process of the statistical phase includes: after the current data backup node or the server standby machine receives the statistical information, it extracts the source parameter from it to determine whether the source of the information is legal; if the node has previously exited the verification phase of the u1th copy request, it will only receive the message without performing operations in other statistical phases; if the source of the information is legal, the index and statistical code are extracted from the statistical information to form a statistical result, and the total number of the statistical results is counted; then it is determined whether the following is satisfied: v1>w / 2; wherein v1 represents the total number of statistical results, and w represents the total number of data backup nodes; if the statistical result of the data backup node or the server standby machine satisfies v1>w / 2, a receipt message containing a copy of the corresponding display business information is constructed and sent to the current display terminal, otherwise the receipt message is not sent.

[0080] Combination Figure 5 The formalized model shown, the process of the statistical stage can be described as:

[0081] After entering the statistical phase, each communication node starts timing. 300 milliseconds after the start of timing, if the communication node fails to form a replica σ' F Upon receiving the receipt information, the statistical phase of the u1-th copy request is exited and action ⑩ is executed.

[0082] The data backup node that completes the verification phase sends a copy σ' to other data backup nodes and server standby s1F Statistics The communication node that completes the verification phase loads the communication buffer and reads the data. After the communication buffer is loaded with the byte stream, the communication node will perform the following operations:

[0083] 1) Extract the source parameters from the first 31 bytes. The parameters include device type, device code, port number and IP address, combine them into a signature and verify the legitimacy of the message source.

[0084] 2) If the source of the message is illegal, the communication node stops reading the byte stream and executes action ⑩.

[0085] 3) If the source of the message is legitimate, the communication node Extract the statistical code u1 and MD5 code d T , forming statistical results (u1,d T ), indicating the communication node The MD5 code successfully verified in the u1th statistics is d T The byte stream exists. After receiving the statistical results from other communication nodes, the count v1 of the result increases by 1.

[0086] 4) Let w be the total number of data backup nodes. If the statistical result (u1,d T ) does not satisfy the relationship v1>w / 2, which means that the statistical result (u1,d T )'s data backup nodes are less than half, the communication node will exit the statistical phase of the u1th replica request and execute action ⑩.

[0087] exist Figure 5 In , the total number of data backup nodes is 3, and the counts of data backup nodes c1 and c3 are 1. Data backup nodes c1 and c3 will exit the statistics phase of the u1-th replica request and execute behavior ⑩.

[0088] 5) Statistical results (u1, d T If the count situation v1 of ) satisfies the relationship v1>w / 2, it means that the statistical result (u1,d T ) has more than half of the data backup nodes, and the number of failed data backup nodes in the network does not exceed 1 / 2 of the total number. The communication node finds the MD5 code d from the cache list. T The byte stream is based on The starting byte in and end byte Information, extract data σ F A copy of σ' F And form a copy σ' F Receipt information o F is F The original data content, δk is the signature of the communication node that satisfies the relationship v1>w / 2. The information fault-tolerant method enters the receipt phase of the u1-th copy request.

[0089] exist Figure 5 In the example, the total number of data backup nodes is 3, and the count of server standby s1 is 2. Server standby s1 will send a copy of σ' F Receipt information

[0090] exist Figure 5 In the example, the total number of data backup nodes is 3, and the count of display terminal c2 is 2. Since the verification phase was exited before, display terminal c2 will not send a copy σ' F Receipt information

[0091] (v) Receipt stage.

[0092] See also Figure 1 The flowchart shown in the figure, wherein the current display terminal verifies the received copy, and if the verification is passed, the corresponding display business information is restored using the received copy, and is in the receipt stage of the display business information fault-tolerant method; the process of the receipt stage includes: the current display terminal receives the receipt information containing the copy of the corresponding display business information; if multiple receipt information is received, the receipt information with the earliest reception time is selected; the source parameter extracted from the receipt information with the earliest reception time is used to determine whether the source of the information is legal; if the source of the information is legal, the index and copy data are extracted from the receipt information with the earliest reception time, and the corresponding part of the content in the local display business information is replaced, and the verification information of the replaced display business information is calculated. If it is different from the index, it indicates that there are other invalid data, and the display business information fault-tolerant process continues, otherwise, the verification passes, and the display business information fault-tolerant process is completed.

[0093] Combination Figure 5 The formalized model shown, the process of the receipt stage can be described as:

[0094] The communication node that completes the verification phase sends a copy σ' to the display terminal c0 F Receipt information REP is the receipt information tag. Display terminal c0 loads the communication buffer and reads the data. After the communication buffer is loaded with the byte stream, display terminal c0 will perform the following operations:

[0095] 1) When multiple receipt messages are received, select the receipt message with the earliest receiving time, extract the source parameters from the first 31 bytes. The parameters include device type, device code, port number and IP address, combine them into a signature and verify the legitimacy of the message source.

[0096] 2) If the source of the message is illegal, display terminal c0 stops reading the byte stream and executes action ⑩.

[0097] 3) If the source of the message is legitimate, display terminal c0 from copy σ' F Receipt message Extract the MD5 code d T , start byte End Byte and data content F The display terminal c0 will invalid data σ in the fault-tolerant linked list F Replaced by a copy σ' F , and then calculate the hash value of the byte stream.

[0098] 4) Display terminal c0 calculates the byte stream hash value and compares whether it is d T If not equal to d T This means that the replaced byte stream also contains other invalid data σ F1 , display terminal c0 will find invalid data σ F1 The starting byte End Byte And the data content F1 , and then execute behavior ⑦. The information fault tolerance method enters the triggering stage.

[0099] If the display terminal c0 calculates the byte stream hash value to be equal to d T , then the replaced byte stream no longer contains other invalid data, the detection passes, and the display terminal c0 executes behavior ④, moves the byte stream to the cache list, and then executes behavior ⑤ to notify the information processing logic. All stages of the information fault tolerance method are completed.

[0100] It can be seen from the processes 3) to 4) of the receipt phase that the method can perform fault-tolerant processing on a single invalid data or multiple invalid data to ensure data consistency of multiple communication nodes.

[0101] The information fault tolerance method provided by the embodiment of the present invention is a five-stage protocol, which can achieve the effect of completely consistent display service data between multiple communication nodes under the premise that the number of failed nodes in the network does not exceed 1 / 2 of the total number. Using the specified fields in the data communication protocol of the scheduling centralized system, the application case is made according to the data transmission method of the scheduling centralized system, allowing the scheduling centralized system to ensure data consistency when the display service information contains a single invalid data, and allowing the scheduling centralized system to ensure data consistency when the display service information contains multiple invalid data.

[0102] In order to further understand the present invention, the following three application cases are described based on the working mode of the information fault tolerance method in the dispatching centralized system private network, which are respectively showing that the service information does not contain invalid data, contains a single invalid data, and contains multiple invalid data. 11 、c 21 、c 25 As a data backup node, the server host s0 sends display service information to the display terminal c5, and sends the display service information to the server backup machine s1 and the display terminal c5. 11 、c 21 、c 25 Send the same display service information. s0, s1, c5, c 11 、c 21 、c 25 The signature is formed by the device type, device code, port number and IP address of each communication node. The initial value of the statistical code u1 of the server standby machine s1 is 0. In each application case, the display service information and data backup received by the communication cache of the display terminal c5 during the triggering phase are shown in Table 1.

[0103]

[0104] Table 1 Specific information of byte stream of information fault tolerance method application case

[0105] Example 1

[0106] When the displayed business information does not contain invalid data, the overall process is as follows Figure 6 As shown, the application examples of the information fault tolerance method are as follows:

[0107] 1) The server host s0 sends the display service information to the display terminal c5, and the display terminal c5 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0108] 2) After the signature information is verified, the display terminal c5 first loads the MD5 code 66A2C42039F77905F2F8C6CBB4D43978 in the business information, and then calculates the MD5 code of the entire displayed business information. Since the displayed business information does not contain invalid data, the MD5 code in the business information is consistent with the calculation result.

[0109] 3) Since the MD5 code in the service information is consistent with the calculation result, it can be determined that the byte stream received by the communication buffer does not contain invalid data. Display terminal c0 exits the trigger process and executes actions ① and ⑤ to receive data normally.

[0110] Example 2

[0111] When the displayed business information contains a single invalid data, the overall process is as follows Figure 7 As shown, the application examples of the information fault tolerance method are as follows:

[0112] 1) The server host s0 sends the display service information to the display terminal c5, and the display terminal c5 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0113] 2) After the signature information is verified, the display terminal c5 first loads the MD5 code 66A2C42039F77905F2F8C6CBB4D43978 in the business information, and then calculates the MD5 code of the entire display business information. Since the display business information contains a single invalid data, the MD5 code in the business information is inconsistent with the calculation result.

[0114] 3) Since the MD5 code in the business information is inconsistent with the calculation result, it can be determined that the byte stream received by the communication cache contains invalid data, and the display terminal c5 starts to detect invalid data. While reading the communication cache, the display terminal c5 detects whether each data is within the expected data range. The display terminal c5 reads 65535 at the position where the starting byte is 400 and the ending byte is 402 in the communication cache. This value is not within the data range [0,32]. It is thus determined that the invalid data 0 is located at the position where the starting byte is 400 and the ending byte is 402 in the byte stream, and the invalid value is 65535. The MD5 code of the byte stream is 66A2C42039F77905F2F8C6CBB4D43978.

[0115] 4) Display terminal c5 executes actions ③ and ⑦, and sends the request information of the copy of invalid data 0 composed of the start byte, end byte, and MD5 code of invalid data 0 to the server standby machine s1. The information fault tolerance method enters the request stage.

[0116] 5) Display terminal c5 sends the request information to server standby machine s1, and server standby machine s1 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0117] 6) After the signature information passes the verification, the statistical code is increased by 1, the server standby machine s1 loads the MD5 code, start byte and end byte in the request information, and then uses the current statistical code 1 to form the verification information of the invalid data 0 copy and send it to the display terminal c 11 、c 21 、c 25 After the sending is completed, the information fault tolerance method enters the verification phase of the first copy request.

[0118] 7) The server standby machine s1 searches the cache list for a byte stream with an MD5 code of 66A2C42039F77905F2F8C6CBB4D43978. The check result shows that s1 has a copy of invalid data 0, and the verification passes.

[0119] 8) Server standby machine s1 sends the verification information to display terminal c 11 、c 21 、c 25 , display terminal c 11 、c 21 、c 25 Load the communication buffer and read the device type, device code, port number and IP address in the byte stream to form signature information.

[0120] 9) After the signature information is verified, the terminal c is displayed 11 、c 21 、c 25 Take the MD5 code from the verification information and search for the byte stream in the cache list. The check result is displayed on terminal c 11 、c 25 There is a copy of invalid data 0, and the verification passes. 21 There is no copy of invalid data 0, verification fails, c 21 For failed nodes, terminal c is displayed 21 Exit the verification phase of the first replica request and execute action ⑩.

[0121] 10) Display terminal c 11 、c 25 The statistical code 1, the start byte 400, and the end byte 402 are taken out from the verification information to form the statistical information of the invalid data 0 copy and sent to the display terminal c. 11 、c 21 、c 25 and server standby s1. The information fault tolerance method enters the statistical phase of the first replica request.

[0122] 11) Display terminal c 11 、c 25 Start timing and send statistical information to the display terminal c 11 、c 21 、c 25 and server standby machine s1, display terminal c 11 、c 25 The server standby machine s1 loads the communication cache and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0123] 12) After the signature information is verified, the terminal c is displayed 11 、c 25The server standby machine s1 extracts the MD5 code and the statistical code from the statistical information, forms a statistical result (66A2C42039F77905F2F8C6CBB4D43978,1) and counts it, indicating that the byte stream corresponding to the MD5 code exists in the first copy request. Display terminal c 11 、c 25 The statistical results of the server standby machine s1 are 1, 1, and 2 respectively.

[0124] 13) The total number of data backup nodes is 3, and the display terminal c 11 、c 25 The statistical result count of the server standby machine s1 is greater than 1 / 2 of the total. Display terminal c 11 、c 25 Exit the statistics phase of the first copy request and execute action ⑩. Display terminal c 21 The statistical result count is greater than 1 / 2 of the total. Since the verification phase was exited before, the terminal c is displayed. 21 No receipt information for the invalid data copy 0 will be sent. The server standby machine s1 takes out the start byte 400 and the end byte 402 from the statistical information, finds the byte stream corresponding to the MD5 code from the cache list, and then reads the original data content 15 to form the receipt information for the invalid data copy 0 and sends it to the display terminal c5. The information fault tolerance method enters the receipt phase of the first copy request.

[0125] 14) The server standby machine s1 sends the receipt information to the display terminal c5, and the display terminal c5 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form the signature information.

[0126] 15) After the signature information passes the verification, the display terminal c5 takes out the MD5 code 66A2C42039F77905F2F8C6CBB4D43978, the start byte 400, the end byte 402 and the data content 15 from the verification information, and then finds the byte stream in the fault-tolerant list and replaces the invalid data 65535 with the original data 15.

[0127] 16) Display terminal c5 calculates the hash value of the byte stream, and the calculation result is consistent with the MD5 code taken from the verification information, indicating that the byte stream no longer contains other invalid data, and the detection passes. Display terminal c5 executes behavior ④, moves the byte stream to the cache list, and then executes behavior ⑤ to notify the information processing logic. All stages of the information fault tolerance method are completed.

[0128] Example 3

[0129] When the displayed business information contains multiple invalid data, the overall process is as follows Figure 8 As shown, the application examples of the information fault tolerance method are as follows:

[0130] 1) The server host s0 sends the display service information to the display terminal c5, and the display terminal c5 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0131] 2) After the signature information is verified, the display terminal c5 first loads the MD5 code 66A2C42039F77905F2F8C6CBB4D43978 in the business information, and then calculates the MD5 code of the entire display business information. Since the display business information contains a single invalid data, the MD5 code in the business information is inconsistent with the calculation result.

[0132] 3) Since the MD5 code in the service information is inconsistent with the calculation result, it can be determined that the byte stream received by the communication buffer contains invalid data.

[0133] According to the data, display terminal c5 starts to detect invalid data. While reading the communication buffer, display terminal c5 detects whether each data is within the expected data range. Display terminal c5 reads 5 at the communication buffer starting byte 400 and ending byte 402, which is within the data range [0,32]. Since it is impossible to determine the exact position of invalid data 1, the starting byte is 0 and the ending byte is 1300. The invalid value is the entire byte stream, and the MD5 code of the byte stream is 66A2C42039F77905F2F8C6CBB4D43978.

[0134] 4) Display terminal c5 executes actions ③ and ⑦, and sends the request information of the copy of invalid data 1 composed of the start byte, end byte, and MD5 code of invalid data 1 to the server standby machine s1. The information fault tolerance method enters the request stage.

[0135] 5) Display terminal c5 sends the request information to server standby machine s1, and server standby machine s1 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0136] 6) After the signature information passes the verification, the statistical code is increased by 1, the server standby machine s1 loads the MD5 code, start byte and end byte in the request information, and then uses the current statistical code 1 to form the verification information of the invalid data 1 copy and send it to the display terminal c 11 、c 21 、c 25 After the sending is completed, the information fault tolerance method enters the verification phase of the first copy request.

[0137] 7) The server standby machine s1 searches for the byte stream with the MD5 code of 66A2C42039F77905F2F8C6CBB4D43978 in the cache list. The check result is that s1 does not have a copy of invalid data 1, and the verification fails. s1 is a failed node, and the server standby machine s1 exits the verification phase of the first copy request and executes action ⑩.

[0138] 8) Server standby machine s1 sends the verification information to display terminal c 11 、c 21 、c 25 , display terminal c 11 、c 21 、c 25 Load the communication buffer and read the device type, device code, port number and IP address in the byte stream to form signature information.

[0139] 9) After the signature information is verified, the terminal c is displayed 11 、c 21 、c 25 Take the MD5 code from the verification information and search for the byte stream in the cache list. The check result is displayed on terminal c 11 、c 21 、c 25 There is a copy of invalid data 1, and the verification passes.

[0140] 10) Display terminal c 11 、c 21 、c 25 The statistical code 1, the start byte 400, and the end byte 402 are taken out from the verification information to form the statistical information of the invalid data 1 copy and sent to the display terminal c. 11 、c 21 、c 25 and server standby s1. The information fault tolerance method enters the statistical phase of the first replica request.

[0141] 11) Display terminal c 11 、c 21 、c 25 Start timing and send statistical information to the display terminal c 11 、c 21 、c 25 and server standby machine s1, display terminal c 11 、c 21 、c 25 Load the communication buffer and read the device type, device code, port number and IP address in the byte stream to form signature information.

[0142] 12) After the signature information is verified, the terminal c is displayed 11 、c 21 、c25 The MD5 code and the statistical code are taken out from the statistical information to form the statistical result (66A2C42039F77905F2F8C6CBB4D43978,1) and counted, indicating that the byte stream corresponding to the MD5 code exists in the first copy request. Display terminal c 11 、c 21 、c 25 The statistical results are 2, 2, and 2 respectively.

[0143] 13) The total number of data backup nodes is 3, and the display terminal c 21 The statistical result count is greater than 1 / 2 of the total. Since the verification phase was exited before, the terminal c is displayed. 21 No receipt message will be sent for invalid data 0 copies. Display terminal c 11 、c 21 、c 25 The statistical result count is greater than 1 / 2 of the total. Display terminal c 11 、c 21 、c 25 The start byte 400 and the end byte 402 are taken out from the statistical information, the byte stream corresponding to the MD5 code is found from the cache list, and then the original data content 15 is read to form the receipt information of the invalid data 1 copy and send it to the display terminal c5. The information fault tolerance method enters the receipt phase of the first copy request.

[0144] 14) Display terminal c 11 、c 21 、c 25 The receipt information is sent to the display terminal c5, and the display terminal c5 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0145] 15) After the signature information passes the verification, the display terminal c5 takes out the MD5 code 66A2C42039F77905F2F8C6CBB4D43978, the start byte 400, the end byte 402 and the data content 15 from the verification information, and then finds the byte stream in the fault-tolerant list and replaces the specified part of the byte stream with the original data 15.

[0146] 16) Display terminal c5 calculates the hash value of the byte stream, and the calculation result is inconsistent with the MD5 code taken from the verification information. Display terminal c5 continues to detect invalid data. Display terminal c5 reads 7 at the position where the communication buffer starts at 452 and ends at 454. This value is within the data range [0,32]. Since the exact position of invalid data 2 cannot be determined, the position where the starting byte is 0 and the ending byte is 1300 is taken. The invalid value is the entire byte stream, and the MD5 code of the byte stream is 66A2C42039F77905F2F8C6CBB4D43978.

[0147] 17) Display terminal c5 executes actions ③ and ⑦, and sends the request information of the copy of invalid data 2 composed of the start byte, end byte, and MD5 code of invalid data 2 to the server standby machine s1. The information fault tolerance method enters the request stage.

[0148] 18) Display terminal c5 sends the request information to server standby machine s1, and server standby machine s1 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0149] 19) After the signature information passes the verification, the statistical code is increased by 1, the server standby machine s1 loads the MD5 code, start byte and end byte in the request information, and then uses the current statistical code 2 to form the verification information of the invalid data 2 copy and send it to the display terminal c 11 、c 21 、c 25 After the sending is completed, the information fault tolerance method enters the verification phase of the second copy request.

[0150] 20) The server standby machine s1 searches for the byte stream with the MD5 code of 66A2C42039F77905F2F8C6CBB4D43978 in the cache list. The check result is that s1 does not have a copy of the invalid data 2, and the verification fails. s1 is a failed node, and the server standby machine s1 exits the verification phase of the second copy request and executes action ⑩.

[0151] 21) Server standby machine s1 sends the verification information to display terminal c 11 、c 21 、c 25 , display terminal c 11 、c 21 、c 25 Load the communication buffer and read the device type, device code, port number and IP address in the byte stream to form signature information.

[0152] 22) After the signature information is verified, the terminal c is displayed 11 、c 21 、c 25Take the MD5 code from the verification information and search for the byte stream in the cache list. The check result is displayed on terminal c 11 、c 21 、c 25 There is a copy of invalid data 2, and the verification passes.

[0153] 23) Display terminal c 11 、c 21 、c 25 The statistical code 2, the start byte 452, and the end byte 454 are taken out from the verification information to form the statistical information of the invalid data 2 copy and sent to the display terminal c. 11 、c 21 、c 25 and server standby s1. The information fault tolerance method enters the statistical phase of the second replica request.

[0154] 24) Display terminal c 11 、c 21 、c 25 Start timing and send statistical information to the display terminal c 11 、c 21 、c 25 And server standby s1, display terminal c 11 、c 21 、c 25 Load the communication buffer and read the device type, device code, port number and IP address in the byte stream to form signature information.

[0155] 25) After the signature information is verified, the terminal c is displayed 11 、c 21 、c 25 The MD5 code and the statistical code are taken out from the statistical information to form the statistical result (66A2C42039F77905F2F8C6CBB4D43978,2) and counted, indicating that the byte stream corresponding to the MD5 code exists in the second copy request. Display terminal c 11 、c 21 、c 25 The statistical results are 2, 2, and 2 respectively.

[0156] 26) The total number of data backup nodes is 3, and the statistical result count of server standby s1 is greater than 1 / 2 of the total. Since it exited the verification phase before, server standby s1 will not send a receipt message for the invalid copy of data 2. Display terminal c 11 、c 21 、c 25 The statistical result count is greater than 1 / 2 of the total. Display terminal c 11 、c 21 、c 25The start byte 452 and the end byte 454 are taken out from the statistical information, the byte stream corresponding to the MD5 code is found from the cache list, and then the original data content 5 is read to form the receipt information of the invalid data 2 copy and send it to the display terminal c5. The information fault tolerance method enters the receipt stage of the second copy request.

[0157] 27) Display terminal c 11 、c 21 、c 25 The receipt information is sent to the display terminal c5, and the display terminal c5 loads the communication buffer and reads the device type, device code, port number and IP address in the byte stream to form signature information.

[0158] 28) After the signature information passes the verification, the display terminal c5 takes out the MD5 code 66A2C42039F77905F2F8C6CBB4D43978, the start byte 452, the end byte 454 and the data content 5 from the verification information, and then finds the byte stream in the fault-tolerant list and replaces the specified part of the byte stream with the original data 5.

[0159] 29) Display terminal c5 calculates the hash value of the byte stream, and the calculation result is consistent with the MD5 code taken from the verification information, indicating that the byte stream no longer contains other invalid data, and the detection passes. Display terminal c5 executes behavior ④, moves the byte stream to the cache list, and then executes behavior ⑤ to notify the information processing logic. All stages of the information fault tolerance method are completed.

[0160] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above embodiments can be implemented by software, or by means of software plus necessary general hardware platforms. Based on such understanding, the technical solutions of the above embodiments can be embodied in the form of software products, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0161] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A fault-tolerant method for displaying business information in a centralized scheduling system, characterized in that: include: After each display terminal receives the same display service information sent by the server host, it determines whether the display service information it receives is valid data; If the current display terminal determines that the display service information received by itself is invalid data, it generates request information according to the index of the corresponding display service information to request a copy of the corresponding display service information from the preset data backup node and the server backup machine, and verifies the received copy. If the verification is passed, the corresponding display service information is restored using the received copy; wherein the preset data backup node is a number of display terminals; Wherein, if the current display terminal determines that the display service information received by itself is invalid data, then generating request information according to the index of the corresponding display service information to request a copy of the corresponding display service information from the preset data backup node and the server standby machine is in the request stage of the display service information fault tolerance method, and the process of the request stage includes: The current display terminal generates request information for a copy of the corresponding display service information according to the index of the corresponding display service information, and sends the request information to the server standby machine; The server standby machine extracts the source parameter from the request information to determine whether the source of the information is legal; If the information source is legitimate, the value of the statistical code is increased by 1, and combined with the index extracted from the request information, verification information is constructed, and then the verification information is sent to the preset data backup node; After the verification information is sent to the preset data backup node, the verification phase of the display service information fault tolerance method is entered, and the process of the verification phase includes: The server standby machine uses the index to search the local cache list for a byte stream with the same index; if so, it means that a copy of the corresponding display business information exists in the server standby machine cache list, and the server standby machine passes the verification; After receiving the verification information, each data backup node extracts the source parameter from it to determine whether the information source is legal; if the information source is legal, it extracts the index from the verification information and searches the local cache list for a byte stream with the same index; if so, it means that a copy of the corresponding display business information exists in the data backup node cache list, and the data backup node passes the verification; The verified data backup node extracts the index and statistical code from the verification information, constructs statistical information, and transmits it to other data backup nodes and server backup machines; After the verified data backup node transmits the statistical information to other data backup nodes and the server backup machine, the statistical phase of the fault-tolerant method for displaying business information begins. The process of the statistical phase includes: After the current data backup node or server backup receives the statistical information, if it has been verified before, it extracts the source parameter from it to determine whether the information source is legal; if the information source is legal, it extracts the index and statistical code from the statistical information to form a statistical result, and counts the total number of the statistical results; then it determines whether it satisfies: v1>w / 2; where v1 represents the total number of statistical results, and w represents the total number of data backup nodes; If the statistical result of the data backup node or the server standby machine satisfies v1>w / 2, a receipt message containing a copy of the corresponding display service information is constructed and sent to the current display terminal; otherwise, no receipt message is sent.

2. A fault-tolerant method for displaying service information in a centralized scheduling system according to claim 1, characterized in that: Each display terminal includes a communication module and a business logic module; wherein: The communication module includes: a communication cache, a fault tolerance list and a cache list; the communication cache is used to receive and send byte streams corresponding to display service information; when the received byte stream is judged to be invalid data, it is stored in the fault tolerance list; when the received byte stream is judged to be valid data, it is stored in the cache list; the fault tolerance list and the cache list record the MD5 value of the byte stream as an index while storing the byte stream; when a request message is received, the relevant byte stream is sent out through the communication cache according to the index in the request message; The business logic module reads the byte stream in the cache list and displays related display business information.

3. A fault-tolerant method for displaying service information in a centralized scheduling system according to claim 1, characterized in that: After each display terminal receives the same display service information sent by the server host, it determines whether the display service information received by itself is valid data, which is in the triggering stage of the display service information fault tolerance method. The process of the triggering stage includes: Receive display service information sent by the server host; Using the source parameter extracted from the displayed business information, determining whether the source of the information is legal; If the information source is legitimate, verification information is extracted from the displayed service information, and whether the displayed service information is valid data is determined based on the verification information.

4. A fault-tolerant method for displaying service information in a centralized scheduling system according to claim 1, characterized in that: The current display terminal verifies the received copy. If the verification is successful, the corresponding display service information is restored using the received copy, which is in the receipt stage of the display service information fault tolerance method. The process of the receipt stage includes: The current display terminal receives a receipt message containing a copy of the corresponding display service information; if multiple receipt messages are received, the receipt message with the earliest receiving time is selected; Use the source parameters extracted from the earliest receipt information to determine whether the information source is legitimate; If the source of the information is legal, the index and copy data are extracted from the receipt information with the earliest reception time, and the corresponding part of the content in the local displayed business information is replaced, and the verification information of the displayed business information after replacement is calculated. If it is different from the index, it indicates that there is other invalid data, and the display business information fault tolerance process continues. Otherwise, the verification passes and the display business information fault tolerance is completed.

5. A fault-tolerant method for displaying service information in a centralized scheduling system according to claim 1 or 3, characterized in that: The step of judging whether the received display service information is valid data includes: Extract the data content of the display business information and the corresponding MD5 value from the byte stream of the display business information, calculate the MD5 value of the data content of the display business information, and compare it with the extracted MD5 value; if they are consistent, it is valid data; if they are inconsistent, it is invalid data.

6. A fault-tolerant method for displaying service information in a centralized scheduling system according to claim 3, characterized in that: Judging whether the source of information is legal includes: By extracting the source parameters, a signature that uniquely identifies the source of the information is formed. The communication node determines whether the source of the information is legitimate based on the signature of the information. The source parameters include: the device type, device code, port number and IP address of the communication node; the types of communication nodes include: display terminal, server host and server backup; each communication node stores the signatures of all communication nodes in the network.

7. A fault-tolerant method for displaying service information in a centralized scheduling system according to claim 1, characterized in that: Each data σ in the displayed business information is defined as σ=(d,e S ,e E ,o), where d is the MD5 value of the entire business information, and the offset e S is the starting byte of data σ in the communication buffer, offset e E is the end byte occupied by data σ in the communication buffer, and o is the data content of the display business information.

Images