91results about How to "Reduce synchronization overhead" patented technology

The invention discloses a distributed type dynamic cache expanding method and system supporting load balancing, which belong to the technical field of software. The method comprises steps of: 1) monitoring respective resource utilization rate at regular intervals by each cache server; 2) calculating respective weighing load value Li according to the current monitored resource utilization rate, and sending the weighting load value Li to a cache clustering manager by each cache server; 3) calculating current average load value of a distributed cache system by the cache clustering manager according to the weighting load value Li, and executing expansion operation when the current average load value is higher than a threshold thremax; and executing shrink operation when the current average load value is lower than a set threshold thremin. The system comprises the cache servers, a cache client side and the cache clustering manager, wherein the cache servers are connected with the cache client side and the cache clustering manager through the network. The invention ensures the uniform distribution of the network flow among the cache nodes, optimizes the utilization rate of system resources, and solves the problems of ensuring data consistency and continuous availability of services.

The invention discloses a cluster packet synchronization optimization method and system for a distributed deep neutral network. The method comprises the following steps of grouping nodes in a cluster according to the performance, allocating training data according to the node performance, utilizing a synchronous parallel mechanism in the same group, using an asynchronous parallel mechanism between the different groups and using different learning rates between the different groups. The nodes with the similar performance are divided into one group, so that the synchronization overhead can be reduced; more training data can be allocated to the nodes with the good performance, so that the resource utilization rate can be improved; the synchronous parallel mechanism is used in the groups with the small synchronization overhead, so that an advantage of good convergence effect of the synchronous parallel mechanism can be exerted; the asynchronous parallel mechanism is used between the groups with the large synchronization overhead, so that the synchronization overhead can be avoided; the different groups uses the different learning rates to facilitate model convergence. According to the method and the system, a packet synchronization method is used for a parameter synchronization process of the distributed deep neutral network in a heterogeneous cluster, so that the model convergence rate is greatly increased.

The invention discloses a dispatching method and a system of a distributed system. The method comprises the following steps: a dispatching request comprising data reading operation is received by a data dispatcher, and data is stored in at least one entity providing data service in the distributed system; status of each data service corresponding to the dispatching request is determined by the data dispatcher, dispatching response consenting to conduct reading operation on each data service is sent by the data dispatcher when each data service is in an idle/reading status; and each data service is at least one same data service. The invention can effectively solve the defects of resource waste, low task processing efficiency and the like in the distributed dispatching method in the prior art, realizes reasonable resource utilization, and improves task processing efficiency.

The invention discloses a method for synchronizing the time of a wireless sensor network and belongs to the technical field of the wireless sensor network. The method comprises the following steps that: 1) a central node broadcasts synchronization information to a network at a specific time interval and starts a synchronization process; 2) after receiving the synchronization information, a sensornode synchronizes time with a source node of the synchronization information and broadcasts the synchronization information thereof to the network when a channel is free; and 3) after each synchronization process is completed, the sensor node predicts the working frequency of a crystal oscillator configured per se in the current period by a winters method and corrects the logic time thereof according to the prediction result till the start of the next synchronization process. Compared with the prior art, the method can greatly prolong the time interval of period synchronization and reduce synchronization expense and the occupying of a wireless channel and improve the synchronization precision among nodes.

The invention discloses a multi-core and multi-thread construction method for a heat path in a dynamic binary translator. The method comprises the following steps: a basic block translation and object code execution part works as a main thread, and a heat path construction and super block translation part works as a sub-thread; an independent code cache structure in a dynamic binary translator for adaption adopts a design mode of dual code cache, the cache of two codes is under unified management of a hash table function, so that the main thread and the sub-thread can be conducted in parallel in the process of data inquiry and data renewal; and the main thread and the sub-thread are appointed to work on different cores of a multi-core processor combined with hard affinity, and a continuous segment of memory space and two counters are utilized to stimulate a segment of queue, so as to carry out the communication between the threads in machine language level and high-level language level. The invention has the favorable characteristics of high parallelism and low synchronous consumption, and provides new conception and new frame for the optimization work of dynamic binary translators in the future.

The invention relates to a low-energy consumption sleeping monitoring method synchronous relative to time of a wireless sensor network. The traditional method is high in energy consumption. The method in the invention comprises the following steps: in the stage of creating a relative synchronization table at a new node, broadcasting addition request network packets by the new node firstly to obtain synchronizing information of a neighbourhood node; then estimating clock skew, and linearly fitting multigroup of synchronization information of the neighbourhood node to estimate clock drift; and finally saving the sleeping period of the neighbourhood node, the estimated clock skew and the clock drift into the relative synchronization table; and in the stage of prediction and transmission of data packets of the node, realizing relative synchronization with a target node by the node according to the created relative synchronization table, then predicting the waking time at the next time according to the sleeping period of the node, setting a transmission timer, and finally transmitting data packets by a short permeable when the transmission timer is triggered. According to the invention, the energy overhead for sending the data packets by the node can be saved, and the idle time of a transmitting node is reduced, and the sleeping time of the transmitting node is increased.

The invention discloses a packet-based metadata server cluster management method. The packet-based metadata server cluster management method includes that N MDSs (metadata servers) in an MDS cluster are divided into M packets, each packet contains only one primary MDS, the others are secondary MDSs; a Hash value range of an MD5 Hash algorithm is evenly divided into S subsections which are evenly distributed to N MDSs management in M packets; each MDS adopts one subsection positioning table inside a packet and one subsection positioning table outside the packet to store distribution records of the subsections; one optional MDS receives a metadata object location request, the corresponding subsection is calculated and located according to a metadata object path name; a subsection heat degree table is stored in each MDS, when one MDS returns query hit information of one subsection, the MDS calculates and updates heat degree corresponding to the subsection heat degree table thereof. By the method, the problems that metadata mapping relations are fixed, metadata targeting efficiency is low and MDS cluster load is unbalanced in an existing method can be solved.

The invention provides a collaborative virtual network mapping method, comprising the following steps: (1) when a virtual network request arrives, entering a central controller to wait for mapping; (2) selecting an virtual network request with the top priority in a queue by the central controller to carry out mapping; (3) for the virtual network request, if the number of virtual nodes thereof is smaller than a set threshold, a topological structure is simple, and no subregional mapping is needed, accomplishing mapping according to a simple network mapping method; and otherwise, carrying out topology preprocessing on the virtual network request by the central controller to decompose the same into a plurality of virtual sub-networks, and mapping each virtual sub-network according to the simple network mapping method by the central controller. According to the method provided by the invention, relative advantages of a centralized algorithm and a distributed algorithm are fully integrated to achieve better mapping performance.

The embodiment of the present invention provides a machine learning method, a master node, work nodes and a distributed machine learning system which are used to reduce the synchronization overhead ofmachine learning. The master node of the distributed machine learning system starts a parameter training process, the work nodes that join the parameter training process are determined, and time information corresponding to the parameter training process is sent to the work nodes, wherein the time information includes an end time of the parameter training process. After the work nodes receive a notification that the master node determines that the work nodes join the parameter training process, the time information corresponding to the parameter training process sent by the master node is obtained. The parameter training is carried out in a time range indicated by the time information, and the master node updates global parameters based on obtained training sub results after the master node receives training sub results sent by work nodes which join the parameter training process.

The invention relates to an indirect control system and method of real time flow. The said system is composed of sending/receiving buffer memory and manipulative indexing queue. Each sending unit of big data block generated by each data is established relation with a sending index queue. Because the data generating and network sending does not happen at the same time and is not finished at one time, when generating the other big data block, the network layer sending is performed using the sending index queue, and the sending index queue is in duty-cycle operation. The management is performed based on the use proportion of the sending capacity of the said node and the receiving capacity of the opposite part to obtain the aim of flow control. The receiving end is operated in the same way. The network layer receives the small data block and the final consumer of data is big data block composed of small data blocks. The said system and method can greatly reduce the cost of flow control depending on protocol and the in-phase cost in node, and the real-time performance of data transmission on under layer in packet network is increased, and the transmission quality of stream media is effectively improved.

The invention is applicable to the technical field of wireless communication and provides a distributed beam forming system and a carrier synchronization method of transmitting antennas at the source end of the distributed beam forming system. The transmitting antennas at the source end of the distributed beam forming system can realize accurate time slot control, can conduct frequency and phase estimation to received signals and can estimate phase shift information caused by channel time delay. The carrier synchronization method fully utilizes the broadcasting characteristics of wireless links and realizes the accurate synchronization of carrier frequency and phase of the distributed beam forming system through accurate time slot control and channel estimation. Compared with the traditional carrier synchronization method, the carrier synchronization method provided by the invention has the advantages that the synchronization overhead is greatly reduced, the time slot needed for synchronization is decreased to M from 2M-1 (wherein M is the number of source-end base stations) and the effective communication time of the system is increased.

The invention discloses a thread division method for avoiding unrelated dependence on a many-core processor structure. The method comprises the following steps of profiling to determine a loop structure with parallel potential; determining a control flow diagram of the loop iteration body; determining a data flow diagram of the loop iteration body; determining the number of derivative speculation threads; performing thread division through dependence separation; performing thread encapsulation. Based on the current situation that the existing many-core thread division mechanisms all introduce unrelated dependence by taking the instruction basic block as a minimum unit, the invention provides a fine-grit thread division method based on dependence separation, which performs further fine-gritting of iteration inside the loop, and divides a serial program into simple and independent threads for speculative execution through unrelated data dependence between minimal threads, thereby reducing the influence on synchronous overhead caused by unnecessary dependence between speculative threads from the source.

The invention discloses a Beidou/global position system (GPS) time signal-based time service system for a communication network. The system comprises a power module 1, a Beidou module 2, a GPS module 3, a clock module 4, a master control module 5 and a panel module 6, which are combined into a whole. Beidou/GPS time is used for synchronizing the clock of a constant temperature crystal, the accuracy and stability of the clock frequency of the crystal are improved, high-accuracy and high-stability radio station time service signals and standard time service signals are output through the clock, and an external time service signal input interface is provided. A precision phase difference compensation technology and a time service error control technology are adopted, so that the synchronization time of a frequency hopping radio station is shortened, synchronization hold-in and synchronization maintenance during a radio silence period are ensured, and the synchronization overhead of the radio station is reduced. High-accuracy RS232-level and RS422-level standard time service signals are provided, so that the requirements of modern communication for the high accuracy of time signals can be met. The system has the characteristics of rational design, high reliability, high environmental adaptability, small size, convenience for use and the like.

The invention provides a data synchronization method and system. The method comprises the steps that a first database system acquires an SQL statement sent by an application program to a second database system; the first database system executes database operation corresponding to the SQL statement; and according to state records of database operation executed by the first database system and thesecond database system, the first database system performs database operation on a first database thereof, so that the first database is consistent with a second database of the second database system. Through the data synchronization method and system, the problem that in the prior art, a database synchronization technology has low efficiency in the remote synchronization field or does not support synchronization of heterogeneous databases is solved, database synchronization efficiency is improved, database synchronization expenditure is lowered, and support of the heterogeneous databases isrealized.

The invention provides a wireless sensor network routing method with high robustness and low delay. The wireless sensor network routing method comprises several stages of network initialization, period detection, path discovery and data forwarding, and comprises the following steps: sending an initialization packet by a base station, receiving the initialization packet by a node, establishing a neighbor node set, and periodically broadcasting a detection packet; replying a detection ACK packet by the node after waiting for a random time; updating the neighbor node set; and when data need to be sent, starting the path discovery, finding a fast path leading to a destination node, making response by the destination node after receiving the detection, determining assistance nodes on the way of the path, finally returning acknowledgement to a source node, sending the data by the source node according to a detection result, making decision by each node on the way according to the detected information and delay information, and finally sending the data to the destination node. According to the method, the average end-to-end delay is shortened by the reliable path discovery, the robustness is improved on the basis of ensuring the delay by using all kinds of fault-tolerant mechanisms, and no synchronization is required, therefore the synchronization cost is reduced.

The invention relates to terminal equipment and discloses a clock control method for slaves and a baseband chip. On and off of a clock of a slave are not controlled by means of software any more but controlled according to statuses of HSEL signals and HTRANS signals. Control is performed from bottom hardware, so that memory modules for storing system codes and external memory controller modules which cannot be switched off by the traditional software method can be switched off, and the process is simple, efficient and riskless and is free of delay required by software in judging. When accessing the slave is not required, on and off of the clock of the slave can be controlled timely, so that system power consumption is lowered greatly.

The invention belongs to the technical field of wireless communication network, and discloses a wired and wireless hybrid Internet of Things system and a clustering method. The method comprises the steps of initializing a network, clustering terminal nodes, determining the size of a time block occupied by each cluster, determining the size of a tie slot, and updating data by the terminal nodes. The quantity of the conflicted terminal nodes is reduced by the way of distributing a period of specific time slot for each cluster, through clustering in combination with a network optimization methodaccording to the quantity of the terminal nodes in the network, the data sizes needing to be uploaded by the terminal nodes, and the condition of channels from the terminal nodes to a convergence node; the deficiency that the uploading rate of the terminal node in the network is affected due to the fact that a standard LoRaWAN protocol provided by a current LoRa alliance does not consider that thefrequent conflicts are caused by simultaneous uploading of the lots of terminal nodes is overcome, and the uploading rates from the terminal nodes to the convergence node in the wired and wireless hybrid Internet of Things are effectively improved.

The invention discloses a multi-core processor synchronization method based on a delay fence synchronization operation instruction, and the method comprises the steps: enabling all participating coreprocessors to send out a synchronization arrival signal of the core processor at a synchronization arrival station, and confirming whether other core processors participating in the fence synchronization all arrive at a synchronization inspection station; and if yes, enabling the core processor to continue to execute, otherwise, enabling the core processor to enter a waiting state until the last arrived signal sent by the core processor is checked by the core processor. The synchronous arrival station is a pipeline station where the synchronous arrival station is located in a self-synchronousstate updating mode; the synchronous check station is a pipeline station where the synchronous state of other cores is inquired, and when the synchronous check station and the synchronous arrival station are not the same pipeline station, the non-adjacent synchronization mode is delay synchronization. The method has the advantages that the method is realized based on any instruction type, extra fence synchronization operation can be reduced, and the transaction synchronization efficiency is improved.

The invention provides a 5G multi-user LDPC code high-speed decoder based on a GPU and a decoding method thereof. The 5G multi-user LDPC code high-speed decoder comprises a high-speed decoder architecture and a high-speed decoding method. The decoding method comprises the following steps: 1, initializing a storage space of a host end; 2, initializing the GPU equipment; 3, carrying out LDPC basis matrix information structure weight description; 4, the host side dispatches GPU decoding; 5, copying LLR information; 6, distributing a corresponding thread number by the GPU end according to the user code block information, selecting a corresponding basis matrix information structural body, and performing iterative decoding based on a hierarchical minimum sum algorithm; 7, symbol judgment; and 8, returning the result to the host end. According to the method, the characteristics of a hierarchical decoding algorithm and the architecture characteristics of the GPU are fully combined, GPU on-chip resources are fully utilized, the memory access efficiency and the utilization rate of a data calculation unit are improved, the decoding time of a single code block is shortened while the resource consumption of the single code block is reduced, and the overall information throughput is improved; the decoding mode is more suitable for processing multi-cell and multi-user LDPC code block decoding in an actual scene.