Multi-server data receiving and sending method and device for OBU

Abstract

The present invention relates to a multi-server data receiving and sending method and device for OBU, comprising the following: using multiple servers to interact with OBU for data, and taking into account the operation stability of the server itself during the interaction process, performing preliminary screening to find a more suitable server by calculating the operation retention rate, and then re-screening based on the running status of the distributed server node in the previous task to remove the server with poor operation status, and then the selected distributed server node responds to the data interaction request of the target OBU, which can avoid the problems of low efficiency and insufficient task completion quality caused by the overload of a single server. When the server data storing the complete log file is lost, the lost content can be quickly restored, and when the data of several other servers that do not store the complete log file is lost, the lost content can also be quickly restored, with great loss tolerance, and can ensure the data security of important log files.

Description

Technical Field

[0001] The present invention relates to the technical field related to OBU data interaction, and in particular to a multi-server data receiving and sending method and device for OBU. Background Art

[0002] During operation, the OBU needs to interact with the server for a large amount of data, such as sending the real-time status information of the vehicle to the server, regularly obtaining the latest map data and real-time traffic information from the server to help the driver plan the best route, avoid congested areas, security authentication and identity verification, software and firmware updates, server monitoring of the OBU status, and user data synchronization.

[0003] The existing method is mostly to interact with OBU through a pre-established main server. This method can generally meet the needs of the above data interaction, but there are still the following problems. On the one hand, since the main server may have an abnormal failure or maintenance, it cannot meet the communication needs of OBU; on the other hand, using a single server to interact with OBU for data, in the face of a large amount of data interaction, it is difficult to avoid the problems of low efficiency and insufficient task completion quality caused by the heavy load of a single server; on the other hand, since there are often important log contents in the OBU, if data is stored through a single server, there will be problems of data loss or damage caused by the failure of a single server. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the deficiencies of the prior art and to provide a multi-server data receiving and sending method and device for OBU.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] Specifically, a multi-server data receiving and sending method for OBU is proposed, including the following:

[0007] Using predetermined servers as distributed server nodes, and using all distributed server nodes to jointly build a distributed server network;

[0008] Obtaining a data interaction request of a target OBU, and parsing the data content requirement of the target OBU in the data interaction request;

[0009] Finding and selecting a distributed server node that can meet the data content requirement in the distributed server network as a preliminary distributed server node;

[0010] Calculating the current server operation retention rates of all preliminary distributed server nodes, and sorting the preliminary distributed server nodes in ascending order based on the current server operation retention rates;

[0011] The preliminary distributed server nodes that are ranked in the top N items are defined as the screening distributed server nodes. If the number of nodes is less than N, all of them are selected.

[0012] The screened distributed server nodes are further eliminated based on the running status of the distributed server nodes in the previous task to obtain the selected distributed server nodes;

[0013] The data interaction request of the target OBU is responded to by selecting a distributed server node.

[0014] Further, specifically, the current server operation retention rate of all preliminary distributed server nodes is calculated, including,

[0015] For any initial distributed server node,

[0016] The preset time range is T, and the real-time CPU occupancy values ​​and real-time processing data flow values ​​of M preliminary distributed server nodes within the time period from 2T to T from the current time are randomly sampled, and a total of M sampling data are obtained;

[0017] With the real-time CPU occupancy value as the horizontal axis and the real-time processing data flow value as the vertical axis, M sampling data correspond to M first sampling points;

[0018] Performing curve fitting on the M first sampling points by using a curve fitting algorithm to obtain a first curve;

[0019] Randomly sample the real-time CPU occupancy values ​​and real-time data processing flow values ​​of M preliminary distributed server nodes within the current T time period, and obtain a total of M sampling data corresponding to the second sampling point;

[0020] Calculate the shortest distance between each second sampling point and the first curve to obtain M shortest distances in total;

[0021] The number of the shortest distances below the first preset value among the M shortest distances is counted and recorded as L;

[0022] The value of L / M is used as the current server operation retention rate.

[0023] Further, specifically, the screened distributed server nodes are further eliminated based on the running status of the distributed server nodes in the previous task, including:

[0024] For any selected distributed server node,

[0025] Obtain the actual end time of the previous task, and calculate the running tolerance time of the previous task based on the processing status of the actual operation unit in the process;

[0026] Determine whether the actual end time is less than the running tolerance time. If so, keep the current screening distributed server node; otherwise, remove the current screening distributed server node.

[0027] Further, specifically, the operation tolerance time of executing the previous task is calculated based on the processing status of the actual operation unit in the process, including:

[0028] Obtain the task processing time of all actual operation units contained in the process when the distributed server node executes the last task, and sort the task processing time of each actual operation unit in the order of task processing to form a sequence T-array, then make a difference between two adjacent elements in T-array to obtain multiple difference values, and form a sequence Tc-array with the positive difference values ​​among the multiple difference values;

[0029] It is agreed that Tc-array(f) represents the fth element in the sequence Tc-array; when searching the sequence Tc-array in the adjacent range of f, when Tc-array(f)>Tc-array(f+1) and Tc-array(f)>Tc-array(f-1) are found for the first time, the sequence number f at this time is recorded as the local large element, and its sequence number is recorded as Maxf; when searching the sequence Tc-array in the adjacent range of f, when Tc-array(f)<Tc-array(f+1) and Tc-array(f)<Tc-array(f-1) are found for the first time, the sequence number f at this time is recorded as the local small element, and its sequence number is recorded as Minf;

[0030] The two adjacent elements of Tc-array (Maxf) calculated from the sequence T-array, that is, the end time of the task processing time that ends later in the task processing time of the two actual operation units, is recorded as Mt1; the two adjacent elements of Tc-array (Minf) calculated from the sequence T-array, that is, the end time of the task processing time that ends later in the task processing time of the two actual operation units, is recorded as Mt2;

[0031] The running tolerance time for executing the previous task is MT+PT, where MT is the later time between Mt1 and Mt2, and PT is the time length between Mt1 and Mt2.

[0032] Furthermore, the method further comprises:

[0033] When the OBU sends a log file marked as important, it is saved in the following ways:

[0034] Assuming that there are L distributed server nodes in the distributed server network, the log file shown is randomly stored in any distributed server node l;

[0035] The preprocessed log file is segmented by a data segmentation algorithm to obtain L-1 data fragments of the log file shown in the corresponding part, and a unique and unchangeable string ID is assigned to each data fragment;

[0036] The L-1 data fragments are stored in the remaining L-1 distributed server nodes respectively, and the string ID is associated with the corresponding distributed server node.

[0037] Furthermore, the method also includes that when the content of the log file shown in any distributed server node is assumed to be lost, L-1 distributed server nodes other than the distributed server node p can quickly restore the actual content part by using the inverse algorithm of the data segmentation algorithm, and after the recovery is completed, it is stored again in the original manner.

[0038] The present invention also proposes a multi-server data transceiver device for OBU, comprising the following:

[0039] A distributed server network construction module is used to use predetermined servers as distributed server nodes and to construct a distributed server network with all distributed server nodes;

[0040] A data interaction request acquisition module is used to acquire a data interaction request of a target OBU, and parse out the data content requirements of the target OBU in the data interaction request;

[0041] A first selection module is used to find and select a distributed server node that can meet the data content requirement in the distributed server network as a preliminary distributed server node;

[0042] A first calculation module is used to calculate the current server operation retention rate of all preliminary distributed server nodes, and sort the preliminary distributed server nodes in ascending order based on the current server operation retention rate;

[0043] The second selection module is used to select the preliminary distributed server nodes that are ranked in the top N items and define them as screening distributed server nodes. If the number of items is less than N, all of them are selected;

[0044] A third selection module is used to further eliminate the screened distributed server nodes based on the running status of the distributed server nodes in the previous task to obtain the selected distributed server nodes;

[0045] The response module is used to respond to the data interaction request of the target OBU by selecting a distributed server node.

[0046] The beneficial effects of the present invention are:

[0047] The present invention proposes a multi-server data receiving and sending method and device for an OBU. A distributed server network is established to perform data interaction with the OBU using multiple servers. During the interaction, the operation stability of the server itself is considered to perform preliminary screening by calculating the operation retention rate to find a more suitable server. In addition, based on the running status of the distributed server nodes in the previous task, a re-screening is performed to remove the servers with poor operation status. After that, the selected distributed server nodes respond to the data interaction request of the target OBU, thereby avoiding the problems of low efficiency and insufficient task completion quality caused by the excessive load of a single server. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and other features of the present disclosure will become more apparent by describing in detail the embodiments shown in the accompanying drawings. The same reference numerals in the accompanying drawings of the present disclosure represent the same or similar elements. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure. For those skilled in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work. In the accompanying drawings:

[0049] Figure 1 Shown is a flow chart of the multi-server data receiving and sending method for OBU of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other without conflict. The same reference numerals used throughout the drawings indicate the same or similar parts.

[0051] Example 1, reference Figure 1 The present invention proposes a multi-server data receiving and sending method for OBU, comprising the following:

[0052] Step 110: using predetermined servers as distributed server nodes, and using all distributed server nodes to jointly construct a distributed server network;

[0053] Step 120, obtaining a data interaction request of a target OBU, and parsing the data content requirement of the target OBU in the data interaction request;

[0054] Step 130: Find and select a distributed server node that can meet the data content requirement in the distributed server network and record it as a preliminary distributed server node;

[0055] Step 140, calculating the current server operation retention rates of all preliminary distributed server nodes, and sorting the preliminary distributed server nodes in ascending order based on the current server operation retention rates;

[0056] Step 150, select the preliminary distributed server nodes that are ranked in the top N items as the screening distributed server nodes, if the number is less than N items, all of them are selected;

[0057] Step 160: Eliminate the selected distributed server nodes again based on the running status of the distributed server nodes in the previous task to obtain the selected distributed server nodes;

[0058] Step 170: Select a distributed server node to respond to the data interaction request of the target OBU. A mature load balancer on the market can be used to implement multi-server response to the data interaction request of the target OBU.

[0059] In the present embodiment 1, a distributed server network is established to interact with the OBU using multiple servers. During the interaction, the operation stability of the server itself is taken into consideration to perform a preliminary screening to find a more suitable server by calculating the operation retention rate. In addition, based on the running status of the distributed server nodes in the previous task, the servers with poor operation status are re-screened to remove them. After that, the selected distributed server nodes respond to the data interaction request of the target OBU, thereby avoiding the problems of low efficiency and insufficient task completion quality caused by the heavy load of a single server.

[0060] As a preferred embodiment of the present invention, specifically, calculating the current server operation retention rate of all preliminary distributed server nodes includes:

[0061] For any initial distributed server node,

[0062] The preset time range is T, and the real-time CPU occupancy values ​​and real-time processing data flow values ​​of M preliminary distributed server nodes within the time period from 2T to T from the current time are randomly sampled, and a total of M sampling data are obtained;

[0063] With the real-time CPU occupancy value as the horizontal axis and the real-time processing data flow value as the vertical axis, M sampling data correspond to M first sampling points;

[0064] Performing curve fitting on the M first sampling points by using a curve fitting algorithm to obtain a first curve;

[0065] Randomly sample the real-time CPU occupancy values ​​and real-time data processing flow values ​​of M preliminary distributed server nodes within the current T time period, and obtain a total of M sampling data corresponding to the second sampling point;

[0066] Calculate the shortest distance between each second sampling point and the first curve to obtain M shortest distances in total;

[0067] The number of the shortest distances below the first preset value among the M shortest distances is counted and recorded as L;

[0068] The value of L / M is used as the current server operation retention rate.

[0069] In this preferred embodiment, considering that the CPU occupancy value of the server and the data flow value processed by the server are two important performance indicators of the server, the server operation retention rate of the adjacent period is estimated and calculated through continuous period T sampling, which can better find the server with stable operation and ensure the stability of subsequent load balancing scheduling.

[0070] As a preferred embodiment of the present invention, specifically, the screened distributed server nodes are re-eliminated based on the running status of the distributed server nodes in the previous task, including:

[0071] For any selected distributed server node,

[0072] Obtain the actual end time of the previous task, and calculate the running tolerance time of the previous task based on the processing status of the actual operation unit (i.e., thread) in the process;

[0073] Determine whether the actual end time is less than the running tolerance time. If so, keep the current screening distributed server node; otherwise, remove the current screening distributed server node.

[0074] In this preferred embodiment, by calculating the server's running tolerance time in the process of executing the last task and comparing it with its actual completion status, it can be seen whether the server's computing power is insufficient. If it is found to be insufficient, the currently screened distributed server node will be removed to ensure the efficiency of subsequent load balancing scheduling.

[0075] As a preferred embodiment of the present invention, specifically, the operation tolerance time of executing the previous task is calculated based on the processing status of the actual operation unit in the process, including:

[0076] Obtain the task processing time of all actual operation units contained in the process when the distributed server node executes the last task, and sort the task processing time of each actual operation unit in the order of task processing to form a sequence T-array, then make a difference between two adjacent elements in T-array to obtain multiple difference values, and form a sequence Tc-array with the positive difference values ​​among the multiple difference values;

[0077] It is agreed that Tc-array(f) represents the fth element in the sequence Tc-array; when searching the sequence Tc-array in the adjacent range of f, when Tc-array(f)>Tc-array(f+1) and Tc-array(f)>Tc-array(f-1) are found for the first time, the sequence number f at this time is recorded as the local large element, and its sequence number is recorded as Maxf; when searching the sequence Tc-array in the adjacent range of f, when Tc-array(f)<Tc-array(f+1) and Tc-array(f)<Tc-array(f-1) are found for the first time, the sequence number f at this time is recorded as the local small element, and its sequence number is recorded as Minf;

[0078] The two adjacent elements of Tc-array (Maxf) calculated from the sequence T-array, that is, the end time of the task processing time that ends later in the task processing time of the two actual operation units, is recorded as Mt1; the two adjacent elements of Tc-array (Minf) calculated from the sequence T-array, that is, the end time of the task processing time that ends later in the task processing time of the two actual operation units, is recorded as Mt2;

[0079] The running tolerance time for executing the previous task is MT+PT, where MT is the later time between Mt1 and Mt2, and PT is the time length between Mt1 and Mt2.

[0080] In this preferred embodiment, the processing status of the actual operating unit in the process is calculated in the above manner to calculate the operating tolerance time for executing the previous task. The operating tolerance time at which different threads (actual operating units) can stably and efficiently complete task processing in the process of completing task progress can be accurately calculated. Only the server that can complete the current task within the operating tolerance time is considered to have met the operating efficiency standards and can complete subsequent load balancing scheduling tasks.

[0081] As a preferred embodiment of the present invention, the method further comprises:

[0082] When the OBU sends a log file marked as important, it is saved in the following ways:

[0083] Assuming that there are L distributed server nodes in the distributed server network, the log file shown is randomly stored in any distributed server node l;

[0084] The preprocessed log file is segmented by a data segmentation algorithm to obtain L-1 data fragments of the log file shown in the corresponding part, and a unique and unchangeable string ID is assigned to each data fragment;

[0085] The L-1 data fragments are stored in the remaining L-1 distributed server nodes respectively, and the string ID is associated with the corresponding distributed server node.

[0086] The method also includes that when the content of the log file shown in any distributed server node is assumed to be lost, L-1 distributed server nodes other than the distributed server node p can quickly restore the actual content part by using the inverse algorithm of the data segmentation algorithm. After the recovery is completed, it is stored again in the original manner, wherein important log files are predefined in a predefined manner, such as predefining important events about the OBU, and once an important event occurs, the log generated is automatically marked as an important log file.

[0087] In this preferred embodiment, important log files are stored in the above manner, so that when the server data storing the complete log file is lost, the lost content can be quickly restored. When the data of several other servers that do not store the complete log file is lost, the lost content can also be quickly restored. It has a great loss tolerance and can ensure the data security of important log files.

[0088] The present invention also proposes a multi-server data transceiver device for OBU, comprising the following:

[0089] A distributed server network construction module is used to use predetermined servers as distributed server nodes and to construct a distributed server network with all distributed server nodes;

[0090] A data interaction request acquisition module is used to acquire a data interaction request of a target OBU, and parse out the data content requirements of the target OBU in the data interaction request;

[0091] A first selection module is used to find and select a distributed server node that can meet the data content requirement in the distributed server network as a preliminary distributed server node;

[0092] A first calculation module is used to calculate the current server operation retention rate of all preliminary distributed server nodes, and sort the preliminary distributed server nodes in ascending order based on the current server operation retention rate;

[0093] The second selection module is used to select the preliminary distributed server nodes ranked in the top N items as the screening distributed server nodes, and if the number of items is less than N, all of them are selected;

[0094] A third selection module is used to further eliminate the screened distributed server nodes based on the running status of the distributed server nodes in the previous task to obtain the selected distributed server nodes;

[0095] The response module is used to respond to the data interaction request of the target OBU by selecting a distributed server node.

[0096] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of software functional modules.

[0097] If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or system that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0098] Although the description of the present invention has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims in view of the prior art by reference to the appended claims, thereby effectively covering the intended scope of the present invention. In addition, the above description of the present invention is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present invention that have not yet been foreseen may still represent equivalent changes to the present invention.

[0099] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. A multi-server data transceiving method for OBU, characterized in that: Includes the following: Using predetermined servers as distributed server nodes, and using all distributed server nodes to jointly build a distributed server network; Obtaining a data interaction request of a target OBU, and parsing the data content requirement of the target OBU in the data interaction request; Finding and selecting a distributed server node that can meet the data content requirement in the distributed server network as a preliminary distributed server node; Calculating the current server operation retention rates of all preliminary distributed server nodes, and sorting the preliminary distributed server nodes in ascending order based on the current server operation retention rates; The preliminary distributed server nodes that are ranked in the top N items are defined as the screening distributed server nodes. If the number of nodes is less than N, all of them are selected. The screened distributed server nodes are further eliminated based on the running status of the distributed server nodes in the previous task to obtain the selected distributed server nodes; The data interaction request of the target OBU is responded to by selecting a distributed server node.

2. The multi-server data receiving and sending method for OBU according to claim 1, characterized in that: Specifically, the current server operation retention rate of all preliminary distributed server nodes is calculated, including: For any initial distributed server node, The preset time range is T, and the real-time CPU occupancy values ​​and real-time processing data flow values ​​of M preliminary distributed server nodes within the time period from 2T to T from the current time are randomly sampled, and a total of M sampling data are obtained; With the real-time CPU occupancy value as the horizontal axis and the real-time processing data flow value as the vertical axis, M sampling data correspond to M first sampling points; Performing curve fitting on the M first sampling points by using a curve fitting algorithm to obtain a first curve; Randomly sample the real-time CPU occupancy values ​​and real-time data processing flow values ​​of M preliminary distributed server nodes within the current T time period, and obtain a total of M sampling data corresponding to the second sampling point; Calculate the shortest distance between each second sampling point and the first curve to obtain M shortest distances in total; The number of the shortest distances below the first preset value among the M shortest distances is counted and recorded as L; The value of L / M is used as the current server operation retention rate.

3. The multi-server data receiving and sending method for OBU according to claim 2, characterized in that: Specifically, the screened distributed server nodes are eliminated again based on the running status of the distributed server nodes in the previous task, including: For any selected distributed server node, Obtain the actual end time of the previous task, and calculate the running tolerance time of the previous task based on the processing status of the actual operation unit in the process; Determine whether the actual end time is less than the running tolerance time. If so, keep the current screening distributed server node; otherwise, remove the current screening distributed server node.

4. The multi-server data receiving and sending method for OBU according to claim 3, characterized in that: Specifically, the operation tolerance time of the previous task is calculated based on the processing status of the actual operation unit in the process, including: Obtain the task processing time of all actual operation units contained in the process when the distributed server node executes the last task, and sort the task processing time of each actual operation unit in the order of task processing to form a sequence T-array, then make a difference between two adjacent elements in T-array to obtain multiple difference values, and form a sequence Tc-array with the positive difference values ​​among the multiple difference values; It is agreed that Tc-array(f) represents the fth element in the sequence Tc-array; when searching the sequence Tc-array in the adjacent range of f, when Tc-array(f)>Tc-array(f+1) and Tc-array(f)>Tc-array(f-1) are found for the first time, the sequence number f at this time is recorded as the local large element, and its sequence number is recorded as Maxf; when searching the sequence Tc-array in the adjacent range of f, when Tc-array(f)<Tc-array(f+1) and Tc-array(f)<Tc-array(f-1) are found for the first time, the sequence number f at this time is recorded as the local small element, and its sequence number is recorded as Minf; The two adjacent elements of Tc-array (Maxf) calculated from the sequence T-array, that is, the end time of the task processing time that ends later in the task processing time of the two actual operation units, is recorded as Mt1; the two adjacent elements of Tc-array (Minf) calculated from the sequence T-array, that is, the end time of the task processing time that ends later in the task processing time of the two actual operation units, is recorded as Mt2; The running tolerance time for executing the previous task is MT+PT, where MT is the later time between Mt1 and Mt2, and PT is the time length between Mt1 and Mt2.

5. The multi-server data receiving and sending method for OBU according to claim 1, characterized in that: The method further comprises, When the OBU sends a log file marked as important, it is saved in the following ways: Assuming that there are L distributed server nodes in the distributed server network, the log file shown is randomly stored in any distributed server node l; The preprocessed log file is segmented by a data segmentation algorithm to obtain L-1 data fragments of the log file shown in the corresponding part, and a unique and unchangeable string ID is assigned to each data fragment; The L-1 data fragments are stored in the remaining L-1 distributed server nodes respectively, and the string ID is associated with the corresponding distributed server node.

6. The multi-server data receiving and sending method for OBU according to claim 5, characterized in that: The method also includes that when the content of the log file shown in any distributed server node is assumed to be lost, L-1 distributed server nodes other than the distributed server node p can quickly restore the actual content part by using the inverse algorithm of the data segmentation algorithm, and after the recovery is completed, it is stored again in the original manner.

7. A multi-server data transceiver for OBU, characterized in that: Includes the following: A distributed server network construction module is used to use predetermined servers as distributed server nodes and to construct a distributed server network with all distributed server nodes; A data interaction request acquisition module is used to acquire a data interaction request of a target OBU, and parse out the data content requirements of the target OBU in the data interaction request; A first selection module is used to find and select a distributed server node that can meet the data content requirement in the distributed server network as a preliminary distributed server node; A first calculation module is used to calculate the current server operation retention rate of all preliminary distributed server nodes, and sort the preliminary distributed server nodes in ascending order based on the current server operation retention rate; The second selection module is used to select the preliminary distributed server nodes ranked in the top N items as the screening distributed server nodes, and if the number of items is less than N, all of them are selected; A third selection module is used to further eliminate the screened distributed server nodes based on the running status of the distributed server nodes in the previous task to obtain the selected distributed server nodes; The response module is used to respond to the data interaction request of the target OBU by selecting a distributed server node.

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