CN118694464A - Time synchronization method, device and system - Google Patents

Abstract

The present application provides a time synchronization method, device and system, wherein the time synchronization method is applied to a client, including: receiving a time synchronization instruction, and calculating the time offset information between the client and the server based on the time synchronization instruction; obtaining historical time offset information when the time offset information is determined to be abnormal information; determining a reference time offset interval based on the historical time offset information; and updating the current client time of the client based on the time offset information when the time offset information satisfies the reference time offset interval. Through the method provided by the present application, by filtering abnormal time offset information, the time jump problem caused by large time anomalies caused by network fluctuations can be reduced, and the consistency and stability of the system time can be effectively enhanced.

Description

Time synchronization method, device and system

Technical Field

The present application relates to the field of computer technology, and in particular to a time synchronization method, a time synchronization device and system, a computing device, a computer-readable storage medium, and a computer program product.

Background Art

In the development of computer network technology, many operations need to be coordinated. If you want to achieve coordinated operations, you need to have an accurate time synchronization foundation. Network Time Protocol (NTP) is an application layer protocol in the TCP/IP protocol suite, which is used to synchronize the clocks between the client and the server and provide high-precision time correction.

The NTP algorithm measures the time difference between the client and the server by sending and receiving timestamps, calculating the round-trip network delay and the time deviation between the two clocks. The client then uses the network delay and time difference to adjust the local clock to keep it synchronized with the server. In actual applications, network fluctuations may occur. When the network fluctuates, the time deviation acquisition may be inaccurate, which in turn affects the accuracy of synchronization when fine-tuning the clock, causing the client time display to jump, making it impossible to accurately and stably synchronize the time.

Summary of the invention

In view of this, the embodiment of the present application provides a time synchronization method. The present application also relates to a time synchronization device and system, a computing device, a computer-readable storage medium and a computer program product to solve the above problems existing in the prior art.

According to a first aspect of an embodiment of the present application, a time synchronization method is provided, which is applied to a client and includes:

Receiving a time synchronization instruction, and calculating time offset information between the server and the server based on the time synchronization instruction;

In the case where it is determined that the time offset information is abnormal information, obtaining historical time offset information;

Determine a reference time offset interval according to the historical time offset information;

In a case where the time offset information satisfies the reference time offset interval, the current client time of the client is updated based on the time offset information.

According to a second aspect of an embodiment of the present application, a time synchronization system is provided, including a client and a server, wherein:

The client is configured to send a time synchronization message to the server based on a time synchronization instruction;

The server is configured to send a synchronization response message to the client in response to the time synchronization message;

The client is further configured to calculate the time offset information between the client and the server based on the time synchronization message and the synchronization response message; when it is determined that the time offset information is abnormal information, obtain historical time offset information; determine a reference time offset interval based on the historical time offset information; and when the time offset information satisfies the reference time offset interval, update the current client time of the client based on the time offset information.

According to a third aspect of an embodiment of the present application, a time synchronization device is provided, which is applied to a client and includes:

A receiving module, configured to receive a time synchronization instruction, and calculate time offset information between the server and the receiving device based on the time synchronization instruction;

an acquisition module, configured to acquire historical time offset information when determining that the time offset information is abnormal information;

A determination module, configured to determine a reference time offset interval according to the historical time offset information;

An updating module is configured to update the current client time of the client based on the time offset information when the time offset information satisfies the reference time offset interval.

According to a fourth aspect of an embodiment of the present application, a computing device is provided, including:

Memory and processor;

The memory is used to store computer programs/instructions, and the processor is used to execute the computer programs/instructions. When the computer programs/instructions are executed by the processor, the steps of the above-mentioned time synchronization method are implemented.

According to a fifth aspect of an embodiment of the present application, a computer-readable storage medium is provided, which stores a computer program/instruction, and when the computer program/instruction is executed by a processor, the steps of the above-mentioned time synchronization method are implemented.

According to a sixth aspect of an embodiment of the present application, a computer program product is provided, comprising a computer program/instruction, which implements the steps of the above-mentioned time synchronization method when executed by a processor.

The time synchronization method provided in the present application is applied to a client, including receiving a time synchronization instruction, and calculating the time offset information between the client and the server based on the time synchronization instruction; when it is determined that the time offset information is abnormal information, obtaining historical time offset information; determining a reference time offset interval based on the historical time offset information; and when the time offset information satisfies the reference time offset interval, updating the current client time of the client based on the time offset information.

Through the time synchronization method provided in the embodiment of the present application, when performing time synchronization, it is determined whether the current network conditions are normal based on the time offset information. When the time offset information is abnormal information, it is further determined whether the abnormal fluctuation of the time offset information satisfies the time offset interval. When the abnormal fluctuation of the time offset information satisfies the time offset interval, time synchronization is performed. By screening the abnormal time offset information, the time jump problem caused by large time anomalies caused by network fluctuations can be reduced, thereby effectively enhancing the consistency and stability of the system time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a time synchronization method provided by an embodiment of the present application;

FIG2 is a schematic diagram of a time synchronization method provided by an embodiment of the present application;

3 is a schematic flow chart of a time synchronization method applied to a rail transit integrated monitoring system provided in an embodiment of the present application;

FIG4 is a schematic diagram of the structure of a time synchronization device provided by an embodiment of the present application;

FIG5 is a schematic diagram of the structure of a time synchronization system provided by an embodiment of the present application;

FIG6 is a structural block diagram of a computing device provided in an embodiment of the present application.

DETAILED DESCRIPTION

Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific implementation disclosed below.

The terms used in one or more embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of the present application. The singular forms of "a", "said" and "the" used in one or more embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and/or" used in one or more embodiments of the present application refers to and includes any or all possible combinations of one or more associated listed items.

It should be understood that, although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present application, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards in the relevant regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

First, the terms involved in one or more embodiments of the present application are explained.

Network Time Protocol: (NTP) is an application layer protocol in the TCP/IP protocol suite that is used to synchronize the clocks between clients and servers and provide high-precision time correction. The NTP algorithm measures the time difference between the client and the server by sending and receiving timestamps, calculates the round-trip time, i.e., the network delay, and determines the time deviation between the two clocks. The client then uses this information to fine-tune its own clock to keep in sync with the server, and this process is repeated to adapt to changes in network conditions.

The current NTP implementation mainly focuses on providing accurate time synchronization, and calibrates the local clock by calculating the round-trip delay and time deviation between the client and the server through UDP communication. The working principle of the NTP protocol involves exchanging timestamps between the client and the server, and calculating the precise time difference through a specific algorithm. The NTP protocol calibrates the client's clock by calculating the round-trip delay and time deviation. When faced with scenarios with unsatisfactory network conditions, the actual time will show inconsistent speed jumps due to network delays.

Based on this, a time synchronization method is provided in the present application. The present application also relates to a time synchronization device and system, a computing device, a computer-readable storage medium and a computer program product, which are described in detail one by one in the following embodiments.

FIG1 shows a flow chart of a time synchronization method provided according to an embodiment of the present application. The time synchronization method is applied to a client and specifically includes the following steps:

Step 102: Receive a time synchronization instruction, and calculate time offset information between the server and the server based on the time synchronization instruction.

In the application scenario of time synchronization, two terminals are involved, one is the client (also called the calibrated terminal) and the other is the server (also called the master clock). The method provided in this application is applied to the client to adjust the time of the client to synchronize with the server.

The time synchronization instruction can be understood as an instruction for controlling the client to perform time synchronization. The time synchronization instruction can be automatically triggered based on a certain trigger condition, for example, triggered once every fixed time period, or triggered once when performing certain specific tasks. It can also be based on instructions sent by users or other clients. In the method provided in this application, there is no limitation on the method for obtaining the time synchronization instruction, which is subject to actual application.

The time offset information can be understood as the time offset between the client and the server calculated by the time synchronization algorithm. The time synchronization method provided by the present application, based on the received time synchronization instruction, the client performs time interactive synchronization with the server and calculates the time offset information between the client and the server. Specifically, the time offset information between the client and the server is calculated based on the time synchronization instruction, including:

Sending a time synchronization message to a server in response to the time synchronization instruction, and recording a first timestamp of the time synchronization message;

Receive a synchronization response message returned by the server in response to the time synchronization message, and record a fourth timestamp of receiving the synchronization response message, wherein the synchronization response message records a second timestamp of the server receiving the time synchronization message and a third timestamp of sending the synchronization response message;

The current network delay and the current time deviation between the client and the server are calculated according to the first timestamp, the second timestamp, the third timestamp and the fourth timestamp.

In the specific implementation manner provided by the present application, the initial time offset information between the client and the server is calculated based on the time synchronization instruction and is obtained by NTP (Network Time Protocol) algorithm. NTP is a protocol for synchronizing device clocks on a computer network. Its main purpose is to ensure that each device in the network can use the same time standard to coordinate various network activities. The core function of NTP is to enable network devices to obtain highly accurate and consistent time information to ensure the synchronization of various network operations.

The architecture of NTP uses a master-slave architecture, where one or more NTP servers serve as master clock sources and other devices serve as slave clock sources. The master server is usually connected to a high-precision clock source, such as an atomic clock, to provide accurate time information. Clock hierarchy involves forming a hierarchy in the network, where devices at each level provide time information to devices in the upper level through synchronous operation. This hierarchy helps ensure that devices throughout the network receive accurate time information.

In actual applications, the client sends an NTP message (time synchronization message) to the server. The time synchronization message carries a first timestamp T1 when the client sends the time synchronization message.

When the time synchronization message arrives at the server, a second timestamp T2 indicating when the server receives the time synchronization message will be added to the time synchronization message.

The server will give a corresponding response based on the time synchronization message, that is, send a synchronization response message based on the time synchronization message, and record the third timestamp T3 of the server sending the synchronization response message. The first timestamp T1, the second timestamp T2 and the third timestamp T3 are written into the synchronization response message.

The client receives the synchronization response message, and records a fourth timestamp T4 of receiving the synchronization response message.

At this point, the first timestamp T1, the second timestamp T2, the third timestamp T3 and the fourth timestamp T4 are obtained in the client, and the current network delay (Delay) and the current time offset (Offset) of the client relative to the server can be further calculated based on these four timestamps.

Specifically, referring to the following formula 1 and the following formula 2, the current network delay is calculated based on the following formula 1, and the current time deviation is calculated based on the following formula 2.

Delay = (T4 - T1) - (T3 - T2)Formula 1

Offset = ((T2-T1) + (T3-T4)) /2Formula 2

Among them, Delay represents the current network delay of the client relative to the server, Offset represents the current time deviation of the client relative to the server, T1 is the first timestamp, T2 is the second timestamp, T3 is the third timestamp, and T4 is the fourth timestamp. The current network delay and the current time deviation can be regarded as the time offset information corresponding to the time synchronization instruction.

Step 104: When it is determined that the time offset information is abnormal information, historical time offset information is obtained.

After obtaining the time offset information, it is necessary to further determine whether the time offset information is abnormal information. In the method provided in the present application, abnormal information can be understood as abnormal conditions existing in the time offset information.

In a specific implementation manner provided in the present application, the time offset information includes the current network delay and the current time deviation. In this implementation manner, whether it is abnormal information is further determined by the current network delay. Specifically, the method further includes:

When the current network delay is greater than a preset delay threshold, determining that the time offset information is abnormal information;

When the current network delay is less than or equal to the preset delay threshold, it is determined that the time offset information is normal information.

The preset delay threshold is a delay threshold provided in the embodiment of the present application for determining whether the time offset information is abnormal. Generally, the time offset information includes the current network delay. If the current network delay is greater than the preset delay threshold, it means that the time offset information is abnormal information. If the current network delay is less than or equal to the preset delay threshold, it can be determined that the time offset information is normal information.

For example, taking the preset delay threshold of the system as 5 milliseconds, if the current network delay in the time offset information calculated in the above steps is 3 milliseconds, it means that the time offset information is normal information, and the current client time of the client can be directly updated according to the current time deviation in the time offset information. If the current network delay in the time offset information calculated in the above steps is 6 milliseconds, it means that the time offset information is abnormal information, and it is necessary to perform the operation of obtaining the historical time offset information.

The historical time offset information specifically refers to the historical time offset information corresponding to multiple time synchronization instructions before the current time synchronization instruction. For example, before the current time synchronization instruction, the time offset information corresponding to the past 10 time synchronization instructions is counted as the historical time offset information. Or the time offset information corresponding to the past 20 time synchronization instructions is counted as the historical time offset information.

In practical applications, a data structure of preset length, such as an array or a data queue, may be set to store historical time offset information in the data structure of preset length, and when it is determined that the time offset information corresponding to the current time synchronization instruction is abnormal information, the historical time offset information is retrieved from the data structure of preset length.

In another specific implementation provided by the present application, obtaining historical time offset information includes:

A historical time deviation array and a historical network delay array are obtained, wherein the historical time deviation array stores a preset number of historical time deviations, and the historical network delay array stores a preset number of historical network delays.

Furthermore, the time offset information includes network delay and time deviation. Accordingly, the historical time offset information also further includes historical network delay information and historical time deviation information. At the same time, the data structure of the preset length can be divided into a network delay data structure and a time deviation data structure, in which a preset number of historical network delays are stored, and in which a preset number of historical time deviations are stored.

Taking the data structure as a loop array with a length of 50 as an example, a network delay loop array and a time deviation loop array are set in the system, wherein the network delay loop array stores the network delay corresponding to the past 50 time synchronization instructions, and the time deviation loop array stores the time deviation corresponding to the past 50 time synchronization instructions. The loop array stores a preset amount of information. When new data is added to the loop array, the data that enters the loop array earliest will be eliminated. In the method provided in the present application, the preset length of the data structure is an even number.

Step 106: Determine a reference time offset interval according to the historical time offset information.

The reference time offset interval can be understood as a range interval used to determine whether the time offset information is abnormal. When the time offset information is within the reference time offset interval, it can be considered that the time offset information is acceptable, and when the time offset information is outside the reference time offset interval, it is considered that the time offset information is unacceptable.

Therefore, determining the reference time offset interval is very important in the method provided in this application. In the method provided in this application, it is necessary to determine the reference time offset interval based on historical time offset information. The historical time offset information records the time offset information corresponding to the time synchronization instructions of the preset number of times in the past. Determining the reference time offset interval through the historical time offset information can better reflect the recent network status of the client more accurately.

Based on this, in another specific implementation manner provided in the present application, determining a reference time offset interval according to the historical time offset information includes:

Determine a first time deviation and a second time deviation in the historical time deviation array, and determine a first network delay and a second network delay in the historical network delay array;

Determine a reference time deviation interval according to the first time deviation and the second time deviation;

A reference network delay interval is determined according to the first network delay and the second network delay.

In practical applications, the historical time offset information includes historical time deviation and historical network delay. The first time offset and the second time offset are determined from the historical time deviation, and the first network delay and the second network delay are determined from the historical network delay data.

It should be noted that the first time deviation, the second time deviation, the first network delay, and the second network delay are all specific values in the historical time offset information. The historical time offset information includes multiple historical time deviations and multiple network delays, from which the corresponding first time deviation, second time deviation, first network delay, and second network delay are selected.

In order to better reflect the accuracy of selecting the first time deviation, the second time deviation, the first network delay, and the second network delay from the historical time offset information, the first time deviation and the second time deviation are determined in the historical time deviation array, and the first network delay and the second network delay are determined in the historical network delay array, including:

The historical time deviations in the historical time deviation array are sorted in ascending order, and the value of the lower quartile is selected as the first time deviation in the time deviation sorting result, and the value of the upper quartile is selected as the second time deviation;

The historical network delays in the historical network delay array are sorted in ascending order, and the value of the lower quartile is selected as the first network delay in the network delay sorting result, and the value of the upper quartile is selected as the second network delay.

In practical applications, the historical time deviations in the historical time deviation array are sorted in ascending order, and according to the time deviation sorting results, the quartile values are selected as the first time deviation and the second time deviation. Quartiles are also called quartile points, which refer to the values at the 25% and 75% positions when the values are arranged from small to large and divided into four equal parts in statistics. Among them, the value at the 25% position is the lower quartile, and the value at the 75% position is the upper quartile. Quartiles can be used to better understand the distribution of data and better perform data analysis.

Specifically, the value of the lower quartile (the number at the 25% position) from the time deviation sorting result is selected as the first time deviation, and the value of the upper quartile (the number at the 75% position) is selected as the second time deviation; the value of the lower quartile (the number at the 25% position) from the network delay sorting result is selected as the first network delay, and the value of the upper quartile (the number at the 75% position) is selected as the second network delay.

After determining the first time deviation, the second time deviation, the first network delay, and the second network delay, a reference time deviation interval may be determined according to the first time deviation and the second time deviation, and a reference network delay interval may be determined according to the first network delay and the second network delay.

In practical applications, the first time deviation and the second time deviation can be used as the minimum and maximum values of the reference time deviation interval, and the first network delay and the second network delay can be used as the minimum and maximum values of the reference network delay interval. The reference time deviation interval and the reference network delay interval can also be determined according to the algorithm of the time deviation interval provided in the embodiment of the present application.

In a specific implementation manner provided in the present application, determining a reference time deviation interval according to the first time deviation and the second time deviation includes:

Calculate the maximum value of the reference time deviation according to the preset interval upper limit formula, the first time deviation and the second time deviation;

Calculate the minimum value of the reference time deviation according to the preset interval lower bound formula, the first time deviation and the second time deviation;

A reference time deviation interval is determined according to the maximum reference time deviation value and the minimum reference time deviation value.

The preset interval upper bound formula is used to determine the maximum value of a certain interval. Specifically, the preset interval upper bound formula is shown in the following formula 3:

Max = D2+ V*(D2-D1) Formula 3

Among them, Max is the maximum value of the interval; D1 is the lower quartile; D2 is the upper quartile; V is the fluctuation threshold, which is a constant in the method provided in this application.

The maximum value of the interval can be calculated according to the above formula 3. Taking the calculation of the maximum value of the reference time deviation as an example, Max is the maximum value of the reference time deviation, D1 is the first time deviation, and D2 is the second time deviation. V is the fluctuation threshold, which is a constant of 1.5 in the method provided in the embodiment of the present application. The maximum value of the reference time deviation can be calculated by the above formula 3.

The preset interval lower bound formula is used to determine the minimum value of a certain interval. Specifically, the preset interval lower bound formula is shown in the following formula 4:

Min = D1- V*(D2-D1) Formula 4

Among them, Min is the minimum value of the interval; D1 is the lower quartile; D2 is the upper quartile; V is the fluctuation threshold, which is a constant in the method provided in this application.

The minimum value of the interval can be calculated according to the above formula 4. Taking the calculation of the maximum value of the reference time deviation as an example, Min is the minimum value of the reference time deviation, D1 is the first time deviation, and D2 is the second time deviation. V is the fluctuation threshold, which is a constant of 1.5 in the method provided in the embodiment of the present application. The minimum value of the reference time deviation can be calculated by the above formula 4.

The minimum reference time deviation and the maximum reference time deviation can be calculated by using the above formula 3 and formula 4, as well as the first time deviation and the second time deviation, so as to determine the reference time deviation interval according to the minimum reference time deviation and the maximum reference time deviation.

In another specific implementation manner provided in the present application, determining a reference network delay interval according to the first network delay and the second network delay includes:

Calculate the maximum value of the reference network delay according to the preset interval upper bound formula, the first network delay and the second network delay;

Calculate a minimum reference network delay according to a preset interval lower bound formula, the first network delay, and the second network delay;

A reference network delay interval is determined according to the maximum reference network delay value and the minimum reference network delay value.

Based on the same calculation method as the above-mentioned minimum reference time deviation and maximum reference time deviation, the above-mentioned Formula 3 and Formula 4, as well as the first network delay and the second network delay, can be used to calculate the maximum reference network delay and the minimum reference network delay. The reference network delay interval can be further determined by the maximum reference network delay and the minimum reference network delay.

Through the method for determining the reference time deviation interval and the reference network delay interval provided in the embodiment of the present application, the fluctuation interval of the time deviation or network delay can be better calculated. The recent network fluctuation of the client can be statistically analyzed through the historical time offset information, so as to better judge whether the network fluctuation of the time offset information is within the normal range, so as to perform subsequent time synchronization processing.

In a specific implementation provided by the present application, determining a reference time offset interval according to the historical time offset information includes:

Determining first time offset information and second time offset information in the historical time offset information;

Calculate the maximum value of the reference time offset according to the preset interval upper bound formula, the first time offset information and the second time offset information;

Calculate the minimum value of the reference time offset according to the preset interval lower bound formula, the first time offset information and the second time offset information;

A reference time offset interval is determined according to the reference time offset maximum value and the reference time offset minimum value.

Furthermore, determining the first time offset information and the second time offset information in the historical time offset information includes:

Sorting the historical time offset information in ascending order;

In the sorting results, the value of the lower quartile is selected as the first time offset information, and the value of the upper quartile is selected as the second time offset information.

It should be noted that for the specific implementation method of determining the first time offset information and the second time offset information, please refer to the above description of the first time offset and the second time offset. For the specific implementation method of determining the reference time offset interval, please refer to the above description of the reference time offset interval, which will not be repeated here.

Step 108: When the time offset information satisfies the reference time offset interval, the current client time of the client is updated based on the time offset information.

After the above steps are processed, the reference time offset interval can be obtained. Therefore, it can be further determined whether the time offset information satisfies the reference time offset interval. If the time offset information satisfies the reference time offset interval, it means that the current network fluctuation is at a normal level. On the contrary, if the time offset information is outside the reference time offset interval, it means that the current network fluctuation is abnormal.

If the current network fluctuation is at a normal level, the synchronization command can be executed, and the calculated time offset information is used to update the current client time of the client. If the current network fluctuation is abnormal, the time synchronization command will not be processed.

In a specific implementation provided by the present application, the reference time offset interval includes a reference time offset interval and a reference network delay interval, and the time offset information includes a current network delay and a current time offset;

The method further comprises:

In a case where the current time deviation is within the reference time deviation interval and the current network delay is within the reference network delay interval, determining that the time offset information satisfies the reference time offset interval;

In a case where the current time deviation is outside the reference time deviation interval, or the current network delay is outside the reference network delay interval, it is determined that the time offset information does not satisfy the reference time offset interval.

In practical applications, the reference time offset interval specifically includes a reference time offset interval and a reference network delay interval, and the time offset information specifically includes a current network delay and a current time offset. Specifically, when the current network delay is within the reference network delay interval and the current time offset is within the reference time offset interval, it indicates that the current network fluctuation is at a normal level, and it can be determined that the time offset information satisfies the reference time offset interval.

On the contrary, if the current time deviation is outside the reference time deviation interval, or the current network delay is outside the reference network delay interval, it means that the current network fluctuation is at an abnormal level, and it is determined that the time offset information does not meet the reference time offset interval.

In another specific embodiment provided in the present application, the method further comprises:

In a case where the time offset information does not satisfy the reference time offset interval, the current client time of the client is not updated based on the time offset information.

When the time offset information does not satisfy the reference time offset interval, the time synchronization operation in response to the time synchronization instruction is not performed, that is, the current client time of the client is not updated based on the time offset information.

When it is determined that the time offset information satisfies the reference time offset interval, the current client time of the client is updated according to the time offset information. Furthermore, the current client time of the client is updated according to the current time deviation in the time offset information.

In actual applications, regardless of whether the time synchronization instruction is executed, the time offset information corresponding to the time synchronization instruction will be obtained. The time offset information records the network fluctuation between the client and the server in the current situation. In order to better record the network fluctuation information and provide data support for subsequent data processing, the method also includes:

The historical time offset information is updated according to the time offset information.

That is, in the method provided by the present application, the historical time offset information is updated according to the time offset information corresponding to each time synchronization instruction. Specifically, the time offset information is added to the historical time offset information. If the number in the historical time offset information is insufficient, the time offset information can be directly added. If the number in the historical time offset information has reached the threshold, the earliest historical time offset information is taken out, and the current time offset information is added to the historical time offset information.

The time synchronization method provided in the embodiment of the present application is applied to a client, including receiving a time synchronization instruction, and calculating the time offset information between the client and the server based on the time synchronization instruction; when it is determined that the time offset information is abnormal information, obtaining historical time offset information; determining a reference time offset interval based on the historical time offset information; and when the time offset information satisfies the reference time offset interval, updating the current client time of the client based on the time offset information.

Through the method provided by the embodiment of the present application, after obtaining the current time synchronization instruction and calculating the time offset information between the client and the server, the time offset information is further screened to determine whether it is abnormal information. If the time offset information is determined to be abnormal information, it is necessary to further determine whether the time offset information is a network fluctuation within a normal range based on the historical time offset information. Only when the network fluctuation is within the normal range when the time offset information is in the normal range, the current client time will be updated based on the time offset information, otherwise the current time offset information will be discarded. Through this method, the application of erroneous time offset information can be effectively reduced, the client time jump caused by abnormal network fluctuations can be avoided, and the consistency and stability of the system time can be enhanced.

The time synchronization method is further described below in conjunction with Figure 2. Figure 2 shows a schematic diagram of a time synchronization method provided by an embodiment of the present application.

As shown in FIG. 2 , the time synchronization method is applied to the client. The client receives a time synchronization instruction and sends a time synchronization message to the server based on the time synchronization execution. The first timestamp T1 of the client is added to the time synchronization message.

The server receives the time synchronization message sent by the client, and records the second timestamp T2 of the server receiving the message in the time synchronization message. In response to the time synchronization message, the server sends a synchronization response message to the client, adds the first timestamp and the second timestamp to the synchronization response message, and also adds the third timestamp T3 of the server sending the synchronization response message to the synchronization response message. It should be noted that the second timestamp T2 and the third timestamp T3 are both server timestamps of the server.

After receiving the synchronization response message sent by the server, the client will record the fourth timestamp T4 when the client receives the message. So far, the client has collected the time offset information used to calculate the time offset of the client compared to the server. The time offset information specifically includes the current network delay (Delay) and the current time deviation (Offset).

When the current network delay is less than or equal to the preset delay threshold, the local client clock of the client is updated using the current time deviation.

When the current network delay is greater than a preset delay threshold, the historical time deviation and the historical network delay are obtained, a reference time deviation interval is determined according to the historical time deviation, and a reference network delay interval is determined according to the historical network delay.

It is further determined whether the current network delay is within the reference network delay interval and whether the current time deviation is within the reference time deviation interval. If the current network delay is within the reference network delay interval and the current time deviation is within the reference time deviation interval, the local client clock of the client is updated using the current time deviation. Otherwise, the current clock synchronization is not performed.

Referring to FIG. 3 , FIG. 3 shows a schematic flow chart of a time synchronization method applied to a rail transit integrated monitoring system provided by an embodiment of the present application, and the method is applied to a transportation object terminal in the rail transit integrated monitoring system. Specifically, it includes:

Step 302: Receive the current time synchronization instruction, and calculate the current network delay and current time deviation between the server and the server based on the time synchronization instruction.

Step 304: Determine whether the current network delay is greater than a preset delay threshold, if so, execute step 306, if not, execute step 314.

Step 306: Obtain a historical time deviation array and a historical network delay array, obtain at least one historical time deviation from the historical time deviation array, and obtain at least one historical network delay from the historical network delay array.

Step 308: Sort the historical time deviations in ascending order, select the lower quartile value as the first time deviation, select the upper quartile value as the second time deviation in the time deviation sorting result, and determine the reference time deviation interval according to the preset interval upper limit formula and the preset interval lower limit formula.

Step 310: Sort the historical network delays in ascending order, select the lower quartile value as the first network delay, select the upper quartile value as the second network delay in the network delay sorting result, and determine the reference network delay interval according to the preset interval upper limit formula and the preset interval lower limit formula.

Step 312: Determine whether the current time deviation is within the reference time deviation interval and the current network delay is within the reference network delay interval. If so, execute step 314; if not, execute step 316.

Step 314: Update the current terminal time based on the current time deviation.

Step 316: Terminate the current time synchronization instruction.

Step 318: Add the current time deviation to the historical time deviation array, and add the current network delay to the historical network delay array.

Through the method provided by the embodiment of the present application, after obtaining the current time synchronization instruction and calculating the time offset information between the client and the server, the time offset information is further screened to determine whether it is abnormal information. If the time offset information is determined to be abnormal information, it is necessary to further determine whether the time offset information is a network fluctuation within a normal range based on the historical time offset information. Only when the network fluctuation is within the normal range when the time offset information is in the normal range, the current client time will be updated based on the time offset information, otherwise the current time offset information will be discarded. Through this method, the application of erroneous time offset information can be effectively reduced, the client time jump caused by abnormal network fluctuations can be avoided, and the consistency and stability of the system time can be enhanced.

Corresponding to the above method embodiment, the present application also provides a time synchronization device embodiment, and FIG4 shows a schematic diagram of the structure of a time synchronization device provided by an embodiment of the present application. As shown in FIG4, the device includes:

The receiving module 402 is configured to receive a time synchronization instruction and calculate the time offset information between the server and the receiving module based on the time synchronization instruction;

The acquisition module 404 is configured to acquire historical time offset information when it is determined that the time offset information is abnormal information;

A determination module 406 is configured to determine a reference time offset interval according to the historical time offset information;

The updating module 408 is configured to update the current client time of the client based on the time offset information when the time offset information satisfies the reference time offset interval.

Optionally, the receiving module 402 is further configured to:

Sending a time synchronization message to a server in response to the time synchronization instruction, and recording a first timestamp of the time synchronization message;

Receive a synchronization response message returned by the server in response to the time synchronization message, and record a fourth timestamp of receiving the synchronization response message, wherein the synchronization response message records a second timestamp of the server receiving the time synchronization message and a third timestamp of sending the synchronization response message;

The current network delay and the current time deviation between the client and the server are calculated according to the first timestamp, the second timestamp, the third timestamp and the fourth timestamp.

Optionally, the device further includes an abnormal information determination module, configured to:

When the current network delay is greater than a preset delay threshold, determining that the time offset information is abnormal information;

When the current network delay is less than or equal to the preset delay threshold, it is determined that the time offset information is normal information.

Optionally, the acquisition module 404 is further configured to:

A historical time deviation array and a historical network delay array are obtained, wherein the historical time deviation array stores a preset number of historical time deviations, and the historical network delay array stores a preset number of historical network delays.

Optionally, the determining module 406 is further configured to:

Determine a first time deviation and a second time deviation in the historical time deviation array, and determine a first network delay and a second network delay in the historical network delay array;

Determine a reference time deviation interval according to the first time deviation and the second time deviation;

A reference network delay interval is determined according to the first network delay and the second network delay.

Optionally, the determining module 406 is further configured to:

The historical time deviations in the historical time deviation array are sorted in ascending order, and the value of the lower quartile is selected as the first time deviation in the time deviation sorting result, and the value of the upper quartile is selected as the second time deviation;

The historical network delays in the historical network delay array are sorted in ascending order, and the value of the lower quartile is selected as the first network delay in the network delay sorting result, and the value of the upper quartile is selected as the second network delay.

Optionally, the determining module 406 is further configured to:

Calculate the maximum value of the reference time deviation according to the preset interval upper limit formula, the first time deviation and the second time deviation;

Calculate the minimum value of the reference time deviation according to the preset interval lower bound formula, the first time deviation and the second time deviation;

A reference time deviation interval is determined according to the maximum reference time deviation value and the minimum reference time deviation value.

Optionally, the determining module 406 is further configured to:

Calculate the maximum value of the reference network delay according to the preset interval upper bound formula, the first network delay and the second network delay;

Calculate a minimum reference network delay according to a preset interval lower bound formula, the first network delay, and the second network delay;

A reference network delay interval is determined according to the maximum reference network delay value and the minimum reference network delay value.

Optionally, the reference time offset interval includes a reference time deviation interval and a reference network delay interval, and the time offset information includes a current network delay and a current time deviation;

The device also includes a judgment module configured to:

In a case where the current time deviation is within the reference time deviation interval and the current network delay is within the reference network delay interval, determining that the time offset information satisfies the reference time offset interval;

In a case where the current time deviation is outside the reference time deviation interval, or the current network delay is outside the reference network delay interval, it is determined that the time offset information does not satisfy the reference time offset interval.

Optionally, the device further includes a termination module configured to:

In a case where the time offset information does not satisfy the reference time offset interval, the current client time of the client is not updated based on the time offset information.

Optionally, the device further includes an updating module configured to:

The historical time offset information is updated according to the time offset information.

Through the device provided by the embodiment of the present application, after obtaining the current time synchronization instruction and calculating the time offset information between the client and the server, the time offset information is further screened to determine whether it is abnormal information. If the time offset information is determined to be abnormal information, it is necessary to further determine whether the time offset information is a network fluctuation within a normal range based on the historical time offset information. Only when the network fluctuation is within the normal range when the time offset information is in the time offset information, the current client time will be updated based on the time offset information, otherwise the current time offset information will be discarded. Through this method, the application of erroneous time offset information can be effectively reduced, the client time jump caused by abnormal network fluctuations can be avoided, and the consistency and stability of the system time can be enhanced.

FIG5 shows a schematic diagram of the structure of a time synchronization system provided in an embodiment of the present application. As shown in FIG5 , the time synchronization system includes a client 502 and a server 504 .

The client 502 is configured to send a time synchronization message to the server 504 based on the time synchronization instruction;

The server 504 is configured to send a synchronization response message to the client 502 in response to the time synchronization message;

The client 502 is further configured to calculate the time offset information between the client and the server based on the time synchronization message and the synchronization response message; when it is determined that the time offset information is abnormal information, obtain historical time offset information; determine a reference time offset interval based on the historical time offset information; and when the time offset information satisfies the reference time offset interval, update the current client time of the client based on the time offset information.

Through the system provided by the embodiment of the present application, after obtaining the current time synchronization instruction and calculating the time offset information between the client and the server, the time offset information is further screened to determine whether it is abnormal information. If the time offset information is determined to be abnormal information, it is necessary to further determine whether the time offset information is a network fluctuation within a normal range based on the historical time offset information. Only when the network fluctuation is within the normal range when the time offset information is in the normal range, the current client time will be updated based on the time offset information, otherwise the current time offset information will be discarded. Through this method, the application of erroneous time offset information can be effectively reduced, the client time jump caused by abnormal network fluctuations can be avoided, and the consistency and stability of the system time can be enhanced.

The above is a schematic scheme of a time synchronization device of this embodiment. It should be noted that the technical scheme of the time synchronization device and the technical scheme of the above time synchronization method belong to the same concept, and the details not described in detail in the technical scheme of the time synchronization device can be referred to the description of the technical scheme of the above time synchronization method.

Fig. 6 shows a block diagram of a computing device 600 according to an embodiment of the present application. The components of the computing device 600 include but are not limited to a memory 610 and a processor 620. The processor 620 is connected to the memory 610 via a bus 630, and a database 650 is used to store data.

The computing device 600 also includes an access device 640 that enables the computing device 600 to communicate via one or more networks 660. Examples of these networks include a public switched telephone network (PSTN), a local area network (LAN), a wide area network (WAN), a personal area network (PAN), or a combination of communication networks such as the Internet. The access device 640 may include one or more of any type of network interface (e.g., a network interface card (NIC)) of wired or wireless, such as an IEEE 802.11 wireless local area network (WLAN) wireless interface, a world-wide interoperability for microwave access (Wi-MAX) interface, an Ethernet interface, a universal serial bus (USB) interface, a cellular network interface, a Bluetooth interface, a near field communication (NFC) interface, and the like.

In one embodiment of the present application, the above components of the computing device 600 and other components not shown in FIG6 may also be connected to each other, for example, through a bus. It should be understood that the computing device structure block diagram shown in FIG6 is only for illustrative purposes and is not intended to limit the scope of the present application. Those skilled in the art may add or replace other components as needed.

The computing device 600 may be any type of stationary or mobile computing device, including a mobile computer or mobile computing device (e.g., a tablet computer, a personal digital assistant, a laptop computer, a notebook computer, a netbook, etc.), a mobile phone (e.g., a smart phone), a wearable computing device (e.g., a smart watch, smart glasses, etc.), or other types of mobile devices, or a stationary computing device such as a desktop computer or a personal computer (PC). The computing device 600 may also be a mobile or stationary server.

The processor 620 is used to execute the following computer program/instruction, which implements the steps of the above-mentioned time synchronization method when executed by the processor.

The above is a schematic scheme of a computing device of this embodiment. It should be noted that the technical scheme of the computing device and the technical scheme of the above time synchronization method belong to the same concept, and the details not described in detail in the technical scheme of the computing device can be referred to the description of the technical scheme of the above time synchronization method.

An embodiment of the present specification further provides a computer-readable storage medium storing a computer program/instruction, which implements the steps of the above-mentioned time synchronization method when executed by a processor.

The above is a schematic solution of a computer-readable storage medium of this embodiment. It should be noted that the technical solution of the storage medium and the technical solution of the above time synchronization method belong to the same concept, and the details not described in detail in the technical solution of the storage medium can be referred to the description of the technical solution of the above time synchronization method.

An embodiment of the present specification also provides a computer program product, including a computer program/instruction, which implements the steps of the above-mentioned time synchronization method when executed by a processor.

The above is a schematic solution of a computer program product of this embodiment. It should be noted that the technical solution of the computer program product and the technical solution of the above time synchronization method belong to the same concept, and the details not described in detail in the technical solution of the computer program product can be referred to the description of the technical solution of the above time synchronization method.

The above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

The computer instructions include computer program codes, which may be in source code form, object code form, executable files or some intermediate forms, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately increased or decreased according to the requirements of patent practice. For example, in some regions, according to patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

The preferred embodiments of the present application disclosed above are only used to help explain the present application. The optional embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can understand and use the present application well. The present application is only limited by the claims and their full scope and equivalents.

Claims (15)

1. A method for time synchronization, applied to a client, comprising:

Receiving a time synchronization instruction, and calculating time offset information between the time synchronization instruction and a server based on the time synchronization instruction;

Acquiring historical time offset information under the condition that the time offset information is determined to be abnormal information;

determining a reference time offset interval according to the historical time offset information;

and updating the current client time of the client based on the time offset information under the condition that the time offset information meets the reference time offset interval.

2. The method of claim 1, wherein calculating time offset information with a server based on the time synchronization instruction comprises:

responding to the time synchronization instruction, sending a time synchronization message to a server, and recording a first timestamp of the time synchronization message;

Receiving a synchronous response message returned by the server aiming at the time synchronous message, and recording a fourth time stamp for receiving the synchronous response message, wherein the synchronous response message is recorded with a second time stamp for receiving the time synchronous message by the server and a third time stamp for sending the synchronous response message;

and calculating the current network delay and the current time deviation between the client and the server according to the first time stamp, the second time stamp, the third time stamp and the fourth time stamp.

3. The method of claim 2, wherein the method further comprises:

determining that the time offset information is abnormal information under the condition that the current network delay is larger than a preset delay threshold value;

And under the condition that the current network delay is smaller than or equal to the preset delay threshold value, determining the time offset information as normal information.

4. The method of claim 2, wherein obtaining historical time offset information comprises:

Acquiring a historical time deviation array and a historical network delay array, wherein a preset number of historical time deviations are stored in the historical time deviation array, and a preset number of historical network delays are stored in the historical network delay array.

5. The method of claim 4, wherein determining a reference time offset interval from the historical time offset information comprises:

Determining a first time offset and a second time offset in the historical time offset array, and determining a first network delay and a second network delay in the historical network delay array;

Determining a reference time deviation interval according to the first time deviation and the second time deviation;

a reference network delay interval is determined from the first network delay and the second network delay.

6. The method of claim 5, wherein determining a first time offset and a second time offset in the historical time offset array, and determining a first network delay and a second network delay in the historical network delay array, comprises:

Sorting the historical time deviations in the historical time deviation array according to the order from small to large, selecting the value of the lower quartile as a first time deviation and the value of the upper quartile as a second time deviation from the time deviation sorting result;

And sequencing the historical network delays in the historical network delay array according to the order from small to large, selecting the value of the lower quartile as the first network delay and the value of the upper quartile as the second network delay from the network delay sequencing result.

7. The method of claim 5, wherein determining a reference time offset interval from the first time offset and the second time offset comprises:

Calculating a reference time deviation maximum value according to a preset interval upper bound formula, the first time deviation and the second time deviation;

calculating a minimum value of the reference time deviation according to a preset interval lower bound formula, the first time deviation and the second time deviation;

And determining a reference time deviation interval according to the reference time deviation maximum value and the reference time deviation minimum value.

8. The method of claim 5, wherein determining a reference network delay interval from the first network delay and the second network delay comprises:

calculating a reference network delay maximum value according to a preset interval upper bound formula, the first network delay and the second network delay;

Calculating a reference network delay minimum value according to a preset interval lower bound formula, the first network delay and the second network delay;

and determining a reference network delay interval according to the reference network delay maximum value and the reference network delay minimum value.

9. The method of claim 1, wherein the reference time offset interval comprises a reference time offset interval and a reference network delay interval, the time offset information comprising a current network delay and a current time offset;

the method further comprises the steps of:

determining that the time offset information satisfies the reference time offset interval when the current time offset is within the reference time offset interval and the current network delay is within the reference network delay interval;

And determining that the time offset information does not meet the reference time offset interval when the current time offset is outside the reference time offset interval or the current network delay is outside the reference network delay interval.

10. The method of any one of claims 1-9, wherein the method further comprises:

And updating the historical time offset information according to the time offset information.

11. A time synchronization system, comprising a client and a server; wherein,

The client is configured to send a time synchronization message to the server based on a time synchronization instruction;

The server is configured to respond to the time synchronization message and send a synchronization response message to the client;

The client is further configured to calculate time offset information between the client and the server according to the time synchronization message and the synchronization response message; acquiring historical time offset information under the condition that the time offset information is determined to be abnormal information; determining a reference time offset interval according to the historical time offset information; and updating the current client time of the client based on the time offset information under the condition that the time offset information meets the reference time offset interval.

12. A time synchronization apparatus, for use in a client, comprising:

A receiving module configured to receive a time synchronization instruction and calculate time offset information with a server based on the time synchronization instruction;

An acquisition module configured to acquire historical time offset information in the case where the time offset information is determined to be abnormal information;

A determining module configured to determine a reference time offset interval from the historical time offset information;

and an updating module configured to update a current client time of the client based on the time offset information if the time offset information satisfies the reference time offset interval.

13. A computing device, comprising:

a memory and a processor;

The memory is adapted to store a computer program/instruction, the processor being adapted to execute the computer program/instruction, which when executed by the processor performs the steps of the method of any of claims 1 to 10.

14. A computer readable storage medium storing a computer program/instruction, which when executed by a processor performs the steps of the method of any one of claims 1 to 10.

15. A computer program product comprising computer programs/instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 10.