76 results about "Master slave synchronization" patented technology

The invention discloses an IEEE 1588 time synchronization system. By adding a time-stamp processing module, a time-stamp message transceiving sub module, a time-stamp message resolving sub module, a time-stamp message generating sub module, a local time recording register, and an RTC correction / time read-write module in the module are used for combining peripheral components such as a switch module, a PHY and a real-time clock (RTC) module to form a hardware system. When in use, the high precision time synchronization requested by an IEEE 1588v2 protocol can be implemented by using the modes of one-to-one or one-to-many of master-slave synchronization. The invention also discloses a method for implementing the IEEE 1588 time synchronization, which can implement the function of the time synchronization system by processing the time information of master-slave devices in real time. The invention plays an active role in promoting Ethernet construction.

The invention relates to an improved method for time synchronization based on an IEEE 1588 PTP mechanism for a wireless network. The method is characterized by monitoring and intercepting a time information packet of the other adjacent nodes and a main node while exchanging according to the IEEE 1588 PTP mechanism during a time synchronization packet exchanging process under the condition of complying with an IEEE 1588 PTP time information packet exchange mechanism, thereby realizing a slave-slave synchronizing mechanism. The solution is used for expanding the IEEE 1588 PTP master-slave synchronization and can acquire much more time information; under the condition of utilizing the information redundancy acquired from the slave-slave synchronizing mechanism, a linear regression method is adopted for a slave node, so that the estimation for clock offset and frequency shift is more accurate and reliable; the influences caused by dissymmetry of main-secondary paths and insufficient accuracy of timestamp are weakened; the high-precision and high-reliability time synchronization is realized in the wireless network.

The invention relates to a system for realizing microcellular base station synchronization, which is used for the synchronization of GSM; the system comprises: BTS, BSC and Pico; wherein the master-slave synchronization method is adopted between BTSs for realizing synchronization; the hollow port Um of the BTS is adopted for Pico to realize the synchronization between Pico, i.e. the receiving channel of the Um port is used for terminal operation in synchronous receiving state to receive and search the broadcast signal channel BCH frequency points of BTS and then analyze frequency correction signal channel FCCH message so as to obtain BCH carrier timing message, according to timing message calculation and correcting the frequency deviation of local reference clock, the synchronization between Pico is realized. The invention utilizes terminal chipset to make the Pico be operated at two states of either terminal frequency band or base station frequency band, therefore no other base station functions are affected when realizing the synchronization of Pico, thereby enhancing systematic integration degree effectively and reducing systematic manufacture and maintenance cost.

A master / slave synchronization communication system applies IEEE1394, and uses its natural period as a base cycle so as to provide synchronization of all stations with a communication period as an integral multiple of the base cycle, thereby allowing easy scheduling of data transmission / reception. The master / slave synchronization communication system has a communication period which is set to an integral multiple of a natural period of IEEE1394 communications with the natural period considered as a base cycle, each station has a detecting section of a synchronization point being a start timing of the communication period, and a base cycle counter which shows what base cycle number the present cycle is from the synchronization point (The counter value has the same value at all stations after detecting the synchronization point), the master transmits instruction data to each slave based on a transmission management table in which destination slaves of instruction data are previously allocated to each of the base counter values, and each of the slaves transmits response data to the master based on transmission timing information which sets the base cycle counter value where a response is transmitted.

The embodiment of the invention provides an Ethercat master-slave synchronization method and device and a master-slave station system. The method comprises the steps that synchronization configuration stages between Ethercat slave stations are configured in an Ethercat master station, and a fixed configuration period serves as the configuration period of the configuration stages; synchronization configuration stages of the Ethercat master station and the Ethercat slave stations are configured in the Ethercat master station, and synchronization of the Ethercat master station configuration period and the Ethercat slave station synchronization signal period is dynamically determined in the configuration stages. The effect of the configured Ethercat master station is better.

This invention discloses a master-slave synchronization method applicable to a multi-hop wireless sensor network. In an initialization phase, entire network nodes are required to establish a hierarchical structure in the manner of distributing, and acquire levels each node belonged to, and father node and child node information. In a synchronization phase, each level of the father nodes broadcast a synchronization request frame level by level from a root node of the network to initiate a synchronization process, solve through a two-dimensional discrete Markov chain model to get an optimal value of a contention backoff window under the condition of different numbers of the child nodes, and incidentally notify the child nodes about the optimal value simultaneously. After receiving the synchronization request frame, the child nodes compete to reply a synchronization response frame according to the size of the optimal backoff window. After receiving the synchronization response frame, the father nodes compute a time deviation between the father nodes and the child nodes, and notify the child nodes about the time deviation through a synchronization acknowledgment frame. After receiving the synchronization acknowledgment frame, the child nodes adjust the local time so as to finish the synchronization process. The simulation result in EXata proves the validity of the method.

The invention discloses a directional beam based wireless network master-slave synchronization method. The directional beam based wireless network master-slave synchronization method comprises the steps of regarding a node which initiates time synchronization in the network as a master node; correspondingly regarding nodes synchronized with the master node as slave nodes; dividing a master-slave synchronization process into a coarse synchronization stage and a fine synchronization stage based on characteristics of directional beam transmission. In the coarse synchronization stage, the master node initiates a synchronization process through directional broadcasting of a coarse synchronization frame; and in the fine synchronization stage, clock slew of the slave nodes and the master node which receive the coarse synchronization frame successfully is removed through directional interaction between a fine synchronization request frame and a fine synchronization response frame, and the time synchronization is realized. After time synchronization of the slave nodes and the master node is finished, each slave node which serves as a master node broadcasts the coarse synchronization frame directionally to neighbor nodes and initiates the synchronization process for the neighbor nodes to further realize time synchronization among all the nodes in the network. The validity of the method is proved by a simulation experiment in the wireless network simulation environment EXata.

The invention discloses a synchronization task processing method and device based on time slice scheduling. The method includes the steps that a synchronization task is generated according to at leastone synchronization request sent by a slave node; the synchronization task is placed in a task queue; any idle thread in a thread pool acquires the synchronization task from the task queue and executes the synchronization task; whether or not the execution time of the synchronization task reaches the time specified by a preset time slice is determined, and if yes, the synchronization task is reset into the task queue. By adopting the scheme, the number of threads can be decoupled from the number of master-slave relationships, and a large amount of master-slave synchronization work in a systemcan be completed by the threads the number of which is lower than the number of master-slave synchronization relationships in the system, so that the system overhead is significantly reduced, and system resources are saved.

The invention discloses a method for controlling a networked teleoperation system in consideration of limited system performance. The specific method is as follow: under network communication delay, alimited master-slave position synchronization error variable is defined on the basis of a non-linear networked teleoperation system model; on the basis of the defined error variable and a neural network, a self-adaptive neural network control policy for the teleoperation system is designed; and a Lyapunov equation is utilized for giving a self-adaptive neural network and parameter adjustment rule, ensuring that set performance requirement is met while the master-slave synchronization error tends to be converged at zero. By stably operating under the limited performance of the teleoperation system, the method disclosed by the invention ensures the safety of the system, solves the problems of low system convergence speed and low precision under a conventional teleoperation control policy, overcomes the uncertainty of a system model and the influence of outside interference on system performance, and enhances the transient and stable performance and anti-interference performance of the system. Moreover, the method simplifies the process of designing a controller, so that practical application is more benefited.

The embodiment of the invention discloses a master-slave switching method and device for database cluster nodes, equipment and a medium. The method comprises the steps of determining that a first master node breaks down, wherein the first master node is set to establish master-master synchronization with a second master node, and the first master node is set to establish master-slave synchronization with a first slave node; taking the instance original access address of the first slave node as an instance current access address of the first master node to replace the instance original access address of the first master node; and setting the first slave node and the second master node to establish master-master synchronization, so that an application service continues to access a database according to the name of the first master node. According to the technical scheme, when the cluster node breaks down, the cluster node automatically switches to an available node; transparent master-slave switching access is achieved; and a service user does not perceive switching.

The invention discloses a regenerative UTC (Universal Time Coordinated) atomic time ultrahigh precision time frequency synchronization network. The regenerative UTC atomic time ultrahigh precision time frequency synchronization network is connected with a time synchronization master station and a time synchronization slave station through optical fibers. An interprovincial and interurban primary communication network is established and borne on an optical-cable optical transport network. HTF-BITS equipment is respectively arranged on the time synchronization master station and the time synchronization slave station. A caesium clock Cs, a rubidium clock Rb, a DCXO (Digital Control X-tal Crystal Oscillator) or a VCXO (Voltage Control X-tal Crystal Oscillator) is arranged on each piece of HTF-BITS equipment. The ultrahigh precision time frequency synchronization or mutual synchronization between the caesium clocks is completed; or the master-slave synchronization between the caesium clocks and the rubidium clocks is completed; the mutual synchronization between the caesium clocks is completed; the master-slave synchronization between the rubidium clocks and the DCXOs is completed; the mutual synchronization between the DCXOs is completed; the master-slave synchronization between the DCXOs and the VCXOs is completed; and as long as the synchronization network normally operates, any node can be a regenerative UTC atomic time frequency standard. The invention provides the novel all-round underground high-precision time frequency synchronization network which is used for transmitting the high-precision time reference by an underground optical-cable optical transmission system without depending on sky time established by navigation systems such as a GPS (Global Positioning System), the Beidou and the like.

The invention discloses a wave variable four-channel bilateral control method based on master-end force buffer. On the basis of the research on the synchronization performance of a bilateral teleoperation control system, a quantitative measurement function of force feedback of the synchronization of the bilateral control system in the condition of fixed time delay is given by the wave variable four-channel bilateral control method. In a wave variable four-channel bilateral control structure, a force buffer unit and a compensation unit are added to a master-end controller, so that the synchronous control over a master end and a slave end is realized, and the influence of a wave transformation method on the advanced effect of the master-end controller is eliminated. On the basis of synchronization indices provided by the wave variable four-channel bilateral control method, the master-slave synchronization analysis performed on the designed control system indicates that the designed control system has good synchronization performance.

The embodiment of the invention discloses a data management method and a data management system for a centralized clearing system. The data management method according to the embodiment of the invention comprises the following steps of acquiring message data to be written; parsing the message data to be written to obtain message relational data and message content data; storing the message relational data in an RDBMS (relational database management system) database, storing the message content data in an NoSQL (not only structured query language) database, and establishing a message content data query index in the RDBMS database; acquiring a message reading request; acquiring the message relational data and the message content data query index from the RDBMS database according to the message reading request, and querying the message content data in the NoSQL database; reading message information after the message relational data and the message content data are combined. According to the embodiment of the invention, the IO (input / output) overhead of the RDBMS database is reduced, the query cache hit ratio of the RDBMS database is increased, and the master-slave synchronization efficiency of the RDBMS database is improved; meanwhile, the size of data stored in the RDBMS database is reduced, so that the backup and restoration speed of the data in the RDBMS database is increased.

The invention discloses a method for monitoring a master-slave synchronization state of a database. The method comprises the following steps: calling a first programming function and automatically executing a pre-set structured query instruction to obtain an executing result; judging whether the master-slave synchronization state of the database is normal or not according to the executing result. The structured query instruction is automatically executed by utilizing a programming manner, and the master-slave synchronization state of the database is monitored; compared with a manner of manually executing the structured query instruction to monitor the master-slave synchronization state of the database, the structured query instruction is automatically executed, so that the monitoring efficiency of the master-slave synchronization state of the database is relatively high; visibly, the monitoring efficiency of the master-slave synchronization state of the database is easy to improve. Furthermore, the invention also provides a device for monitoring the master-slave synchronization state of the database, and has the advantages corresponding to the method.

The invention provides a short message management system and method based on distributed storage. The method comprises the steps that an application service layer receives first short message data through short message interface modules based on different types of operators, carries out the safety verification based on a preset strategy management model, forms second short message data and corresponding channel data, and sends the data to a data cache layer; the data cache layer caches the second short message data and the channel data, and schedules the second short message data to a corresponding channel based on a scheduling strategy; a persistent layer correspondingly stores the short messages scheduled to a distributed database in a master-slave synchronization mode; and a display layer is used for displaying the short message data to the user based on a query request of the user. Through added database middleware, a group of data is connected in series to form the distributed database so that problems of a capacity, concurrency and horizontal expansion are effectively solved, and the performance and stability of the system are greatly improved.

The invention relates to a container MySQL master-slave synchronization and performance collection implementation method and system. The method comprises the following steps: 1, preparing raw materials; the method comprises the following steps of: creating a MySQL master-slave database system on a Kubernetes platform; the MySQL master-slave database system comprises a master database and a slave database, wherein the main library comprises a mysql main node container, a data sending end container and a main library mysql-exporter container; wherein the main library mysql-exporter container isused for collecting a main library mysql performance parameter; wherein the slave library comprises a mysql slave node container, a data receiving end container and a slave library mysql-exporter container, and the slave library mysql-exporter container is used for collecting the performance parameters of the slave library mysql, so that the performance parameters of the master and standby nodes can be collected and monitored.

The invention discloses a data stream state monitoring and warning system based on master-slave synchronization, which belongs to the field of data governance and is connected with at least one data source and at least one user side. The system comprises a plurality of target databases which are respectively used for storing log data of data sources; the target data monitoring table comprises monitoring information corresponding to each data source; the server comprises a client used for reading log data in a master-slave synchronization mode and writing the log data into a message queue, and a consumption module used for updating a target data monitoring table when the message queue is changed; the alarm module is used for judging whether updating is abnormal or not and outputting push information when updating is abnormal; and the sending end is used for sending the push information to the user end. The method has the beneficial effects that the data is obtained through master-slave synchronization, so that the performance of the target database is not influenced; a plurality of data sources can be docked; the state of the data flow is monitored in real time, and the processing workload in the data governance process is reduced.

The invention provides a method and a system for realizing fault tolerance of a virtual machine. The method comprises the steps of: redundantly operating the virtual machine where an application program is located in a plurality of servers, selecting one server as a master virtual machine, using the rest servers as slave virtual machines, wherein the virtualization configurations of the master virtual machine and the slave virtual machines are the same, and the master virtual machine and the slave virtual machines are redundant backups for fault switching; and enabling the master virtual machine and the slave virtual machines to carry out redundancy processing on the user request, and maintaining the consistency of the external visible states of the master virtual machine and the slave virtual machines through a master-slave synchronization protocol. Compared with the prior art, according to the invention, an efficient master-slave synchronization protocol and an operating system cooperating with a virtual machine monitor are used; the method greatly reduces the tail time delay of user request processing, reduces the frequency of state difference caused by uncertainty of redundantoperation of the master and slave virtual machines, reduces the expenditure of state synchronization of the master and slave virtual machines, remarkably improves the overall throughput of an application program in a fault-tolerant system, and remarkably reduces the delay of request processing.

The invention discloses an edge storage database based on an improved LSM tree, and the database comprises: an index module which is responsible for the maintenance of data internal keys and address information; a value storage module which is responsible for maintaining data internal keys and actual value information; a database function module which is used for converting various complex data structures into internal key-value pairs; a network module which is used for providing a multiplexed TCP service; a database synchronization module which is used for providing master-slave synchronization and multi-master synchronization among multiple nodes of the database; and a user service module which directly interacts with a user through various standardized interfaces. Through the improvement of the LSM tree and the cooperation of multiple modules, a high-performance, low-loss, high-availability and standardized edge storage database is successfully constructed, and compared with an existing Internet-of-Things edge data storage system, the write-in amplification of the system is remarkably reduced.

The invention discloses a master-slave synchronization method and device, a master server and a storage medium. The method comprises the steps that the specific value of storage capacity occupied by an incremental file to storage capacity occupied by a master database backup file is determined; and when the determined specific value meets a preset duplication condition, a slave server is made to duplicate the incremental file in a preset duplication cache region according to maximum displacement of the slave server. Through the master-slave synchronization method and device, the master serverand the storage medium, on the premise of guaranteeing data consistency, master-slave synchronization efficiency is effectively improved, and highly-available time of service is prolonged.

The invention provides a speed limit method and device of redis master-slave full synchronous data. When a timed event set in a preset period starts, a redis master node executes the file synchronization event created before the timed event starts, and the file synchronization event is used for controlling the redis master node to send an rdb file to the redis from the node; according to the sending rate limited by the file synchronization event, synchronization data in the rdb file is sent; the synchronization data is sent and the file synchronization event is deleted within the preset period. Therefore, the speed of master-slave synchronization can be controlled, it is guaranteed that the master-slave synchronization cannot occupy all bandwidth of a network card, and then normal runningof services is guaranteed.

The embodiment of the invention discloses a master-slave time delay monitoring method and a master-slave time delay monitoring device suitable for redis and a storage medium. The method comprises thefollowing steps that a set of key$n is written into a master library Master of redis, the key$n at least comprises keys from 0 to 59, and each key corresponds to one $value; updating the value S1 of the key corresponding to the current second number of the master library Master, and querying the value S2 of the key of the slave library Slave under the same key at the same time; and determining a current master-slave synchronization time delay difference value S3 according to the S1 and the S2. By adopting the method and the system, the redis master-slave database servers are synchronized by adopting a unified time server, so that the system time can be ensured to be unified, and the delay problem between the redis master-slave databases and the master-slave availability can be more intuitively expressed according to the judgment of the system time.

The invention discloses a method and circuit for measuring the rotating speed of a rotary machine, relates to the field of electronic measurement, and solves the synchronous counting of two counters in rotary machine rotating speed measurement. The method comprises the following steps: a rotating speed pulse signal is input into the pin TIM1_ETR of a STM32F103 via an optocoupler; using the STM32F103 as a processor, and setting a timer 1 and a timer 2 in the STM32F103 in a master-slave synchronization counting mode, and achieving cooperative operation of the two timers by means of configuration of a corresponding register so as to achieve synchronous counting; enabling a processing program to calculate the rotating speed and output the rotating speed to a display module; reconfiguring the corresponding register according to a rotating speed calculation result, starting next measurement and continuously repeating the cycle. The method and circuit for measuring the rotating speed of the rotary machine are accurate in rotating speed measurement, stable in measurement data, good in real-time performance and is simple in required peripheral circuit.

The invention discloses a master-slave database switching method, computing equipment and a storage medium. The method comprises the steps of monitoring whether a current first master database crashesor not; when it is monitored that the current first master database crashes, selecting a temporary second master database from a plurality of slave databases according to the data synchronization position information of each slave database; synchronizing the temporary to-be-synchronized data of the second master database to other slave databases by utilizing a master-slave synchronization function; selecting a new third main database; reading to-be-synchronized data of the first main database by utilizing a plug-in in the first main database, and writing the to-be-synchronized data of the first main database into the third main database; and updating the configuration information of the master-slave database after switching. By means of the scheme, when the current master database crashes, the slave database can be switched into the master data in time, and it can be guaranteed that the data is not lost.

The invention discloses a method for making the MFS distributed file system have high availability. The MFS distributed file system used in the method adds a mirror main node and a metadata synchronization module on the original MFS original role and module; the MFS distributed file system comprises a mirror main node and a metadata synchronization module. The mirror master node is responsible forkeeping the state consistent with the master node. The metadata synchronization module is located between the master node and the mirror master node, which is responsible for synchronizing the metadata base data and the metadata incremental modification log, and verifying the authorization of the master node and the mirror master node. The invention transmits the reference metadata of the masternode and the incremental modification log by the master-slave synchronization mechanism to maintain the weak consistency of the metadata of the master node and the mirror node. When the primary node stops serving, the mirror node can quickly promote the primary node and provide storage services to ensure that the primary node is highly available, and at the same time, the operation can be rolled back, thus ensuring the high availability of the MFS file system services.

The invention provides a real-time data association method supporting total update. The method includes a data acquisition module, a data management module, a Redis memory database, and a data association module, the data acquisition module acquires total data required to be synchronized from an external file or an external database and processes the total data; then, the data in the correspondingformat is transmitted to the data management module; the data management module processes the received data; inserting or updating the data into a Redis memory database; the Redis memory database stores various types of associated data, data synchronization is carried out in a master-slave mode, the data association module receives a data association query request, then an association result is queried from the Redis memory database, and after type conversion, the association result is returned to the data association query request. Under the condition of total data updating, the number of data updating in the Redis memory database is reduced, occupation of network and system resources during master-slave synchronization of the Redis memory database is greatly reduced, and the efficiencyof using the Redis memory database for data association can be greatly improved.

The invention discloses an IEEE 1588 time synchronization system. By adding a time-stamp processing module, a time-stamp message transceiving sub module, a time-stamp message resolving sub module, a time-stamp message generating sub module, a local time recording register, and an RTC correction / time read-write module in the module are used for combining peripheral components such as a switch module, a PHY and a real-time clock (RTC) module to form a hardware system. When in use, the high precision time synchronization requested by an IEEE 1588v2 protocol can be implemented by using the modes of one-to-one or one-to-many of master-slave synchronization. The invention also discloses a method for implementing the IEEE 1588 time synchronization, which can implement the function of the time synchronization system by processing the time information of master-slave devices in real time. The invention plays an active role in promoting Ethernet construction.

The invention discloses a method for deduplicating master-slave synchronous data of a MySQL database. The method distinguishes the MySQL database synchronization operation from the data deduplicationoperation, and is executed as two continuous operation steps, namely, after the data synchronization operation is completed, duplicate data is found by comparing the synchronized data with the data inthe synchronization log, and the duplicate data is deleted from the library. The method of the invention does not need to perform locking operation on the database table, does not affect the parallelservice function provided by the database, and does not introduce excessive performance overhead, so the method is superior to the existing solution in the aspects of database operation parallelism and performance overhead.

The invention discloses a data synchronization method and device for master and slave nodes of a database. The method comprises the following steps: starting an output log function of a time sequencetype database on a master node and determining a format of an output log; configuring and starting a master-slave synchronizer of the time sequence type database to continuously monitor an output logof the master node; analyzing all editing operations aiming at the time sequence type database based on the time sequence from the output log; in response to the offline state of the slave node, caching the editing operation as a to-be-synchronized operation into a lightweight database of the master node; in response to the slave node being online, synchronizing the editing operation and the cached to-be-synchronized operation to the slave node. Master-slave data synchronization and master-slave switching can be normally executed offline in the master-slave database, and data integrity is guaranteed.