JPWO2010137229A1 - Periodic process execution system, periodic process execution method, and periodic process execution program - Google Patents

Abstract

The periodic process execution system includes a plurality of external devices that transmit a trigger for executing a periodic process, and a periodic process execution device that causes the external device to periodically execute a process. The periodic process execution device includes trigger transmission determination means and trigger transmission means. The trigger transmission determining means triggers the reception of the trigger from the external device, and the elapsed time from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target has reached a predetermined trigger transmission interval. On the condition that the trigger is transmitted to the external device. The trigger transmission unit transmits the trigger to the external device based on the determination that the trigger transmission determination unit transmits the trigger.

Description

  The present invention relates to a periodic processing execution system that periodically executes processing, and a periodic processing execution device, a periodic processing execution method, and a periodic processing execution program that are applied to the periodic processing execution system.

  There are various systems that require regular processing. An example of a system that requires periodic processing is a system that constructs and uses a distributed hash table (hereinafter referred to as DHT).

  Here, a network using DHT will be described. One of the algorithms for realizing DHT is a code (Chord). The code (Chord) is an algorithm using IDs from 0 to 2 to the 160th power -1. The code (Chord) forms a loop-shaped space by connecting the ID “2 to the 160th power−1” next to the ID “0”. Each node is assigned one ID from among the IDs forming the space. Further, each node holds a node list having IDs that are somewhere before and after its own ID and IDs that are 2 to the power of n. Each node maintains a distributed node list, and manages the nodes in the space by checking the connection status of the nodes in the node list. The number of IDs that can be used in the code (Chord) may be described as the ID space size. For example, when IDs from 0 to 2 to the 160th power −1 are used, the ID space size is 2 to the 160th power.

  In a network using DHT (hereinafter referred to as a DHT network), it is necessary for each node to periodically check the connection status of the nodes in the network. Therefore, for example, when a partial space assigned to each node is changed due to the participation or withdrawal of the node in the DHT network, it is necessary to periodically reconfigure the node list in accordance with the change. In such a network, the node list reconfiguration process is periodically started and executed by each node itself, or in response to a periodic start instruction from another device. In this way, each node periodically reconstructs the node list.

  The system as described above uses a technique for periodically generating an execution instruction (hereinafter referred to as a trigger) for performing processing in order to realize periodic processing. For example, a trigger can be generated periodically by using a technology such as cron (function to execute a program at a predetermined time or interval) provided by an OS (Operating System) of Linux (registered trademark). it can. In addition, it is possible to generate a trigger periodically by starting one process permanently and repeating the process. By transmitting the trigger generated by these methods to another device, the processing performed by the device that receives the trigger can be periodically executed.

  Patent Document 1 describes a communication system capable of repairing a P2P network when an arbitrary node participating in the P2P network leaves. In the communication system described in Patent Document 1, the DHT management unit 23 periodically transmits and receives keep-alive messages. When the DHT management unit 23 detects that a certain content node has left, the DHT management unit 23 transmits a content search message with a ring repair option for searching for the disjoined content node to the upstream node. The other DHT management unit 23 waiting for the message restores the ring by transmitting and receiving a keep-alive message with the content node that has transmitted the message.

Japanese Patent Laying-Open No. 2008-276551 (paragraphs 0048 to 0050, FIG. 3)

  FIG. 12 is a block diagram showing a general DHT network. In the example illustrated in FIG. 12, a plurality of Web servers 92 are connected to the communication network 91. The Web server 92 includes a communication unit 93, an execution unit 94, and a trigger generation unit 95. When the trigger generation unit 95 generates a trigger periodically using cron or the like, the execution unit 94 is triggered by the trigger on the node on the network 91 (for example, the Web server 92) via the communication unit 93. Confirm participation and withdrawal of. Alternatively, when the trigger generation unit 95 periodically generates a trigger by using cron or the like, the execution unit 94 causes the other Web server 92 to periodically participate in the node, Give instructions to confirm withdrawal. The other Web server 92 periodically confirms the participation or withdrawal of the node according to the instruction.

  However, when periodic processing is performed by using cron or a permanent startup of a process, there is a possibility that a load is applied to the own apparatus depending on the setting. For this reason, a rental server or the like places restrictions on the use of cron and the permanent startup of processes, and is allowed to execute processing only when a request from a user or another device occurs, for example. There may be. In such an apparatus, when a process for transmitting a trigger to another apparatus is started, it is necessary to use a request transmitted from another apparatus.

  However, a request transmitted from another device is not necessarily transmitted periodically. Therefore, when a trigger is generated in response to such a request and the trigger is transmitted to another device, there is a problem that the time interval at which the trigger is transmitted to the other device is not constant.

  For example, in the DHT network described above, each device periodically performs processing such as periodic confirmation of the existence of another person or withdrawal of participation (hereinafter referred to as DHT maintenance processing) regardless of a request from the user. There is a need to do. However, in the rental server in which the use of cron or the permanent start-up of the process is restricted, a trigger for executing the DHT maintenance process cannot be periodically generated in the own device. It is also impossible to periodically send a DHT maintenance process trigger to the device.

  Further, in the communication system described in Patent Document 1, it is necessary for each node to periodically transmit and receive keep-alive messages. Therefore, it is desirable that a message can be periodically transmitted to other devices even if the device cannot regularly start message transmission processing within each node.

  Therefore, the present invention provides a periodic processing execution system that can execute periodic processing even when a generation source that periodically generates a trigger cannot be used, and a periodic processing execution device that is applied to the periodic processing execution system. It is an object to provide a process execution method and a periodic process execution program.

  The periodic process execution device according to the present invention is triggered by the fact that the trigger for executing the periodic process is received from the external device, from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target. On the condition that the elapsed time has reached a predetermined trigger transmission interval, the trigger transmission determining means for determining that the trigger is transmitted to the external device, and the trigger transmission determining means having determined that the trigger is transmitted And trigger transmitting means for transmitting a trigger to an external device.

  A periodic process execution system according to the present invention includes a plurality of external devices that transmit a trigger for executing a periodic process, and a periodic process execution device that causes the external device to periodically execute a process. However, when the trigger is received from the external device, the elapsed time from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target has reached the predetermined trigger transmission interval. Trigger transmission determining means for determining that a trigger is transmitted to the external device, and trigger transmission means for transmitting a trigger to the external device based on the determination that the trigger transmission determining means transmits a trigger. It is characterized by that.

  The periodic process execution method according to the present invention is based on the fact that the trigger for executing the periodic process is received from the external device, and the trigger is transmitted from the time when the trigger was transmitted to the external device in the past. On the condition that the elapsed time has reached a predetermined trigger transmission interval, it is determined that the trigger is transmitted to the external device, and the trigger is transmitted to the external device based on the determination that the trigger is transmitted. It is characterized by transmitting.

  The periodic process execution program according to the present invention has transmitted a trigger in the past to an external apparatus to which a trigger is to be transmitted, when a trigger for causing the computer to execute the periodic process is received from the external apparatus. A trigger is transmitted in the trigger transmission determination process and the trigger transmission determination process for determining that a trigger is transmitted to the external device on the condition that the elapsed time from the time has reached a predetermined trigger transmission interval. Based on the determination, trigger transmission processing for transmitting a trigger to an external device is executed.

  According to the present invention, it is possible to execute periodic processing even when a source that periodically generates a trigger cannot be used.

It is a block diagram which shows the minimum structure of this invention. It is a block diagram which shows the example of the regular process execution system in the 1st Embodiment of this invention. It is explanatory drawing which shows the example of the network structure by which a periodic process execution system is implement | achieved, and a URL list. It is a flowchart which shows the example of a process of the trigger transmission judgment part 34a. It is explanatory drawing which shows the example of the transmission timing of a trigger. It is explanatory drawing which shows the example when the transmission timing of a trigger is early and late. It is explanatory drawing which shows the example in the case of increasing and decreasing a trigger. It is a block diagram which shows the example of the regular process execution system in the 2nd Embodiment of this invention. It is explanatory drawing which shows the example of the network structure by which a periodic process execution system is implement | achieved, and a next hop list | wrist. It is a flowchart which shows the example of a process of the trigger transmission judgment part 34b. It is explanatory drawing which shows the example of operation | movement which each web server transmits a trigger. 1 is a block diagram showing a general DHT network. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the minimum configuration of the present invention will be described. FIG. 1 is a block diagram showing the minimum configuration of the present invention. The periodic processing execution system according to the present invention includes a plurality of external devices 70 that transmit a trigger for executing periodic processing, and a periodic processing execution device 80 that causes the external device 70 to periodically execute processing. .

  The regular process execution device 80 includes a trigger transmission determination unit 81 and a trigger transmission unit 82.

  The trigger transmission determination means 81 is triggered transmission that has been determined in advance from the time when the trigger was transmitted to the external device 70 that is the trigger transmission target in response to reception of the trigger from the external device 70. It is determined that a trigger is transmitted to the external device 70 on the condition that the interval has been reached.

  The trigger transmission unit 82 transmits a trigger to the external device 70 based on the determination that the trigger transmission determination unit 81 transmits a trigger.

  With such a configuration, it is possible to execute periodic processing even when a source that periodically generates a trigger cannot be used. That is, even when a device that regularly generates a trigger cannot be used, the periodic processing execution device 80 that has received the trigger from the external device 70 has reached a predetermined trigger transmission interval. The trigger is transmitted to the apparatus on the condition of. Therefore, the apparatus can perform periodic processing.

Embodiment 1. FIG.
FIG. 2 is a block diagram illustrating an example of a periodic process execution system according to the first embodiment of the present invention. The regular processing execution system in the present embodiment includes a Web server 21a and Web servers 22 to 25. The web server 21 a and the web servers 22 to 25 are connected to each other via the communication network 100. In addition, although the communication network 100 is implement | achieved by the internet etc., the form of the communication network 100 is not specifically limited. In the following description, the Web server may be referred to as a node.

  In the periodic processing execution system according to the present embodiment, each Web server forms a ring-shaped network, and triggers are sequentially transmitted to other Web servers along the network. Each Web server that has received the trigger performs processing based on the received trigger. The first trigger is input into the system by the user, for example.

  The Web server 21a includes a communication unit 31, a trigger input unit 32, an execution unit 33, a trigger transmission determination unit 34a, a trigger transmission time management unit 35, a next hop list unit 36a, a trigger output unit 37, a trigger And a transmission time storage unit 38.

  The trigger transmission time storage unit 38 transmits a previous trigger (hereinafter referred to as trigger transmission time tl) from the Web server 21a to the other Web servers 22 to 25 (hereinafter simply referred to as other Web servers). Remember). Specifically, the trigger transmission time storage unit 38 is realized by a magnetic disk device or the like included in the Web server 21a. The trigger transmission time tl is stored in the trigger transmission time storage unit 38 by the trigger transmission time management unit 35 described later.

  When the communication unit 31 receives a trigger (also referred to as a query) from another Web server via the communication network 100, the communication unit 31 starts processing instructed by the query. In the present embodiment, a case will be described in which the communication unit 31 causes the trigger input unit 32 to execute a process when a query is received from another Web server.

  When a trigger is input via the communication unit 31, the trigger input unit 32 instructs the execution unit 33 and the trigger transmission determination unit 34a to execute processing.

  The execution unit 33 executes processing (tasks) periodically executed by the Web server 21a. Specifically, the execution unit 33 executes a periodic process in response to an instruction from the trigger input unit 32. For example, the execution unit 33 executes a process for confirming the participation or withdrawal of a node in the DHT network (that is, the DHT maintenance process) using ping, TCP / IP, or the like provided by the Linux (registered trademark) OS. However, the process performed by the execution unit 33 is not limited to the DHT maintenance process. For example, the execution unit 33 periodically collects update information of a web log (hereinafter referred to as a blog) or periodically notifies file update information in a file system managed using DHT. May be.

  The trigger transmission determination unit 34a determines whether or not trigger transmission is possible, a trigger transmission waiting time, and the like based on the transmission time (that is, the trigger transmission time tl) at which the other Web server is instructed to transmit the previous trigger. For example, the trigger transmission determination unit 34a describes a time period (hereinafter referred to as a trigger transmission interval td) that is determined in advance as an interval for generating a trigger from the time when the trigger was transmitted in the past to another Web server. ) Is determined to transmit a trigger to the Web server. When the trigger transmission determining unit 34 a determines to transmit a trigger, the trigger transmission determining unit 34 a issues a trigger transmission instruction to the trigger output unit 37. When the trigger transmission determination unit 34 a issues a trigger transmission instruction, the trigger transmission determination unit 34 a instructs the trigger transmission time management unit 35 to store the trigger transmission time tl in the trigger transmission time storage unit 38.

  In addition, the trigger transmission determination unit 34a instructs the trigger transmission time management unit 35 to calculate the trigger transmission prohibition time tr. The trigger transmission prohibition time tr is a time during which the generation of a trigger is temporarily retained in order to keep the trigger transmission interval td with respect to another Web server. Specifically, the trigger transmission prohibition time tr is calculated by subtracting the elapsed time te from the trigger transmission interval td, where the elapsed time te is the time elapsed from the previous trigger transmission time tl to the current time t. That is, the trigger transmission prohibition time tr can be said to be a difference between the elapsed time from the time when the trigger is transmitted in the past to the time when the trigger is received and the trigger transmission interval td. When the trigger transmission prohibition time tr becomes 0, the trigger transmission determination unit 34a determines that the trigger transmission is performed to another Web server, and issues a trigger transmission instruction to the trigger output unit 37.

  As described above, the trigger transmission determining unit 34a calculates the trigger transmission prohibition time tr and issues a trigger transmission instruction after the trigger transmission prohibition time tr has elapsed, so that the trigger transmission interval with respect to another Web server can be adjusted.

  The trigger transmission determination unit 34a may adjust the trigger transmission instruction timing using a value other than the trigger transmission prohibition time tr. For example, the trigger transmission determination unit 34a calculates the distance between another Web server that transmits a trigger to the Web server 21a and the Web server 21a, and based on the distance, the time during which the trigger transmission is retained (hereinafter referred to as “trigger transmission”) , Written as the trigger residence time tw). When the calculated trigger residence time tw is greater than the trigger transmission inhibition time tr, the trigger transmission determination unit 34a may determine that the trigger is transmitted after the trigger residence time tw has elapsed.

  Hereinafter, a method for calculating the trigger residence time tw will be described. In the following description, an ID based on a code (Chord) is given to each Web server so as to be connected in a ring shape, and each Web server sequentially sends a trigger transmission instruction to the Web server that is closest to the own device. The case of performing will be described. That is, this ID is an identifier for identifying each Web server, and it can be said that the entire ID forms a loop. The trigger transmission determination unit 34a calculates a value (hereinafter, referred to as a normalized distance dn) obtained by dividing the difference between the IDs assigned to each Web server by the ID space size as a distance between the Web servers. Then, the trigger transmission determination unit 34a calculates the trigger residence time tw by multiplying the trigger transmission interval td by the normalized distance dn.

  The normalized distance dn is a value that becomes 1 when the trigger goes around the ring shape. Therefore, after each Web server receives the trigger, each trigger is transmitted after the elapse of time calculated by multiplying the trigger transmission interval td by the normalized distance dn. td. Each Web server transmits a trigger after the trigger residence time tw calculated in this way has elapsed, so that the trigger can be transmitted while adjusting to a constant trigger transmission interval td.

  When there are a plurality of trigger transmission instruction numbers (that is, triggers maintained in the loop) in the loop, a value obtained by multiplying the number of triggers (hereinafter referred to as the number of triggers in the loop nt) is the trigger retention. It is good also as time tw. By doing so, even if a plurality of triggers are transmitted in the loop, the trigger transmission instruction can be performed by adjusting to a constant trigger transmission interval td.

  On the other hand, the trigger transmission timing may be delayed due to a network delay or a Web server processing delay. Therefore, the trigger transmission determining unit 34a may multiply the trigger residence time tw by a coefficient (hereinafter referred to as an acceleration coefficient k) for shortening the trigger residence time tw. Here, the acceleration coefficient k is a positive number of 1 or less. By calculating the trigger residence time tw in this way, the trigger transmission determination unit 34a can adjust the trigger transmission interval td to a constant timing even when the arrival of the trigger is late.

  As described above, the trigger transmission determination unit 34a adjusts the trigger transmission timing using the trigger residence time tw and the trigger transmission prohibition time tr, so that the trigger transmission instruction is issued even when the trigger arrival interval is deviated. The timing to perform can be adjusted to a constant trigger transmission interval td.

  In addition, the trigger transmission determination unit 34a performs an instruction to transmit a query to a Web server arbitrarily selected from the URL list after giving a trigger transmission instruction, based on a predetermined probability p, a trigger output unit 37. You may go to At this time, the trigger output unit 37 may transmit the trigger to the Web server selected based on the random value from the URL list, but the method of selecting the Web server is not limited to the above method. For example, the trigger transmission determination unit 34a may transmit a trigger to a Web server selected according to the order of the list.

  A trigger transmission instruction that is periodically performed may disappear without propagating to another Web server due to a Web server down or network failure (hereinafter referred to as “trigger transmission failure”). Even in such a case, it is possible to prevent the trigger transmission instruction performed in the entire system from completely disappearing by performing the trigger transmission instruction in addition to the trigger transmission instruction performed periodically. In the following description, this probability p is referred to as a trigger replication probability p. The trigger duplication probability p is a parameter determined according to a system to which the periodic process execution system is applied, and is determined according to a rate at which the number of triggers sequentially transmitted is attenuated.

  On the other hand, when the trigger transmission determination unit 34a waits for a trigger transmission instruction to another Web server and receives a trigger from another Web server, the trigger transmission determination unit 34a suppresses a new trigger transmission instruction to be performed based on the received trigger. May be. By suppressing trigger transmission instructions in this way, it is possible to prevent the number of trigger transmission instructions on the network from increasing excessively.

  By using these methods, trigger transmission between nodes is interrupted due to a trigger transmission failure, etc., trigger transmission instructions are interrupted, and too many trigger transmission instructions cause a node or network to be down. Can be prevented.

  The trigger transmission time management unit 35 stores the trigger transmission time tl in the trigger transmission time storage unit 38 in response to an instruction from the trigger transmission determination unit 34a. In addition, the trigger transmission time management unit 35 calculates a trigger transmission prohibition time tr in response to an instruction from the trigger transmission determination unit 34a and notifies the trigger transmission determination unit 34a.

  The next hop list unit 36a stores a URL (Uniform Resource Locator) list of the Web server. Specifically, the next hop list unit 36a is realized by a magnetic disk device or the like included in the Web server 21a. The next hop list unit 36a stores a predetermined number of URLs of the Web server in order from the Web server closest to the Web server 21a.

  FIG. 3 is an explanatory diagram illustrating an example of a URL configuration and a network configuration in which the periodic processing execution system is realized. In the network shown in the example of FIG. 3A, the distance between the Web servers shown on the circumference is close to the order in which they are arranged on the circumference. That is, in the example illustrated in FIG. 3A, the Web server close to the Web server A is the Web server B, and thereafter, the Web server E is sequentially arranged. This distance may be determined based on the normalized distance dn. In the example shown in FIG. 3B, the URL list of the Web server is created with the direction of the arrow shown on the circumference as the forward direction. For example, when the Web servers A to E are connected with the contents illustrated in FIG. 3A, the next hop list unit 36a of the Web server A is transmitted from the Web server B as illustrated in FIG. A URL list arranged in the order of Web server E is stored.

  Further, the URL of the Web server stored in the next hop list section 36a is not limited to the Web server that is close to the Web server 21a. For example, in the case of a DHT network, the URL of a Web server corresponding to an ID that is separated every 2 factories from the ID assigned to the Web server 21a may be stored.

  The contents of the URL list are updated, for example, when the execution unit 33 detects joining or leaving of a node. Since the method for updating the URL list is widely known, the description thereof is omitted here.

  When the trigger output unit 37 receives an instruction from the trigger transmission determination unit 34a to transmit a trigger to another Web server, the Web server at the closest distance from the URL list stored in the next hop list unit 36a. Send a query to The trigger output unit 37 may transfer the received trigger content as it is to the next Web server, or may generate a new trigger and transmit it to the next Web server. Further, when the trigger transmission unit 37 fails to transmit a query to the Web server at the nearest distance due to a trigger transmission failure or the like, the trigger output unit 37 selects the Web at the next closest distance from the URL list stored in the next hop list unit 36a. Send a query to the server. Hereinafter, the trigger output unit 37 sequentially tries to transmit a query to a Web server at a short distance until the query is successfully transmitted.

  Note that when the query transmission fails, the trigger output unit 37 may set a flag indicating that the transmission failed in the URL in the URL list. The trigger output unit 37 can suppress unnecessary communication to the Web server that failed to transmit by suppressing transmission of the query to the Web server in which this flag is set.

  Since the configuration of the other Web servers (that is, the Web servers 22 to 25) is the same as that of the Web server 21a, detailed description thereof is omitted. In the above description, the case where the periodic process execution system includes four other Web servers has been described. According to the present invention, the number of other Web servers provided in the periodic process execution system is not limited to four, and may be one or two or more.

  Note that all of the Web servers in this system do not necessarily have the same function as the Web server 21a. A plurality of Web servers corresponding to a part of the system may have the same function as the Web server 21a, or only one server in the system may have the same function as the Web server 21a. In this case, a Web server that does not have the same function as the Web server 21a only needs to have a function of receiving a trigger and transmitting the trigger to another device, and a function of adjusting a time interval (that is, a trigger). The transmission determination unit 34a, the access time management unit 35, and the access time storage unit 38) may not be provided. In addition, it can be said that it is more preferable because more servers in the system have the same function as the Web server 21a (that is, the function of adjusting the time interval), so that the accuracy of the regular processing is increased.

  The communication unit 31, the trigger input unit 32, the execution unit 33, the trigger transmission determination unit 34a, the trigger transmission time management unit 35, and the trigger output unit 37 are computers that operate according to a program (periodic process execution program). Implemented by the CPU. For example, the program is stored in a storage unit (not shown) of the Web server 21a, and the CPU reads the program, and according to the program, the communication unit 31, the trigger input unit 32, the execution unit 33, the trigger transmission determination unit 34a, The trigger transmission time management unit 35 and the trigger output unit 37 may operate. The communication unit 31, the trigger input unit 32, the execution unit 33, the trigger transmission determination unit 34a, the trigger transmission time management unit 35, and the trigger output unit 37 are each realized by dedicated hardware. May be. In addition, the communication unit 31 may be realized by a CPU of a computer that operates according to a program that realizes a general Web server service.

  Next, the operation will be described. FIG. 4 illustrates an example of processing until the trigger transmission determination unit 34a determines whether or not to transmit a trigger according to an instruction from the trigger input unit 32, and performs a trigger transmission instruction to the trigger output unit 37 according to the determination. It is a flowchart to show. In the following description, each node is given an ID based on a code (Chord), and, for example, a trigger given by a user or the like on the network formed by each node to which this ID is given is an in-loop trigger number nt. It shall exist. That is, the in-loop trigger number nt can be said to be an expected value of the number of triggers maintained in the loop.

  The trigger transmission determination unit 34a determines whether or not the trigger transmission instruction 37 is currently waiting for a trigger transmission instruction (step S11). When waiting for a trigger transmission instruction (YES in step S11), the process ends without performing the subsequent determination process. On the other hand, when not waiting for a trigger transmission instruction (NO in step S11), the trigger transmission determining unit 34a determines whether or not a trigger is received from a neighboring node (that is, another Web server) (step S12). . When the trigger is received (YES in step S12), the trigger transmission determining unit 34a calculates a normalized distance dn between the transmission source node and the own node (step S13). That is, the trigger transmission determination unit 34a calculates a value obtained by dividing the difference between IDs assigned to nodes by the ID space size as a distance between the nodes. On the other hand, when a trigger is not received from a neighboring node (NO in step S12), the trigger transmission determining unit 34a determines that the normalized distance dn is 0 (step S14).

  Next, the trigger transmission determining unit 34a calculates the trigger residence time tw (step S15). The trigger residence time tw is calculated by multiplying the acceleration coefficient k, the normalized distance dn, the trigger transmission interval td, and the number of triggers nt in the loop. The trigger transmission determination unit 34a sets the maximum time that the trigger residence time tw can wait for processing of its own node (that is, the longest waiting time that the Web server can withstand. Hereinafter, the maximum allowable waiting time tw_max). It is determined whether or not it exceeds (step S16). The Web server 21a cannot wait for processing that exceeds the maximum allowable waiting time tw_max. Therefore, when the trigger residence time tw exceeds the maximum allowable waiting time tw_max (YES in step S16), the trigger transmission determination unit 34a ends the process. That is, the trigger transmission determination unit 34a does not issue a trigger transmission instruction.

  On the other hand, when the trigger residence time tw does not exceed the maximum allowable waiting time tw_max (NO in step S16), the trigger transmission determination unit 34a instructs the trigger transmission time management unit 35 to calculate the trigger transmission prohibition time tr, and triggers The calculation result input is received from the transmission time management unit 35 (step S17). The trigger transmission determination unit 34a compares the trigger residence time tw with the trigger transmission prohibition time tr, and waits for a trigger transmission instruction for the longer time (step S18). After the standby time elapses, the trigger transmission determination unit 34 a instructs the trigger output unit 37 to transmit a trigger to a neighboring node. The trigger output unit 37 transmits a query (trigger) to neighboring nodes in response to a trigger transmission instruction from the trigger transmission determination unit 34a (step S19). For example, the trigger output unit 37 transmits a query to the Web server closest to the URL list stored in the next hop list unit 36a.

  On the other hand, after sending a trigger transmission instruction to the trigger output unit 37, the trigger transmission determination unit 34a instructs the trigger transmission time management unit 35 to store the trigger transmission time tl in the trigger transmission time storage unit 38. . The trigger transmission time management unit 35 stores the trigger transmission time tl in the trigger transmission time storage unit 38 in response to an instruction from the trigger transmission determination unit 34a (step S20). In addition, after the trigger transmission instruction, the trigger transmission determination unit 34a instructs the trigger output unit 37 to instruct the node selected at random from the URL list to transmit the trigger based on the trigger replication probability p ( Step S21).

  By executing the above processing, triggers are sequentially transmitted between Web servers on a network configured in a ring shape. In addition, since the trigger transmission determination unit 34a periodically transmits a trigger by adjusting the transmission interval, each Web server that has received the trigger can periodically execute the process.

  When operating the system for the first time, trigger transmission is started based on the input of the first trigger by a user or the like. Thereafter, since the trigger is automatically transmitted between the Web servers in the system, the periodic process is continuously executed.

  5 to 7 are explanatory diagrams illustrating examples of trigger transmission timing. Hereinafter, the trigger transmission timing will be described with reference to FIGS. In the following description, an ID based on a code (Chord) is given to each Web server so as to be connected in a ring shape in the order of Web servers A to F, and each Web server is in the order of A to F (however, Next to F, the case where triggers are sequentially transmitted to the Web server adjacent to A) will be described. Also, the distance between the vertical lines shown in the examples of FIGS. 5 to 7 represents the normalized distance dn between the Web servers, and the vertical downward direction represents the passage of time. The number of triggers in the network formed in a ring shape (that is, the number of triggers in the loop nt) is 2.

  When a trigger is transmitted from the Web server A to the Web server B at the timing “1” illustrated in FIG. 5, the Web server B transmits the normalized distance dn, the trigger transmission interval td, and the number of triggers nt in the loop (here Then, the trigger is transmitted to the Web server C after the time multiplied by 2) (that is, the trigger residence time tw) has elapsed. The trigger transmission from the Web server C to the Web server D, the trigger transmission from the Web server D to the Web server E, the trigger transmission from the Web server E to the Web server F, and the trigger transmission from the Web server F to the Web server A are also described above. It is performed after the trigger residence time tw calculated in the same manner as described above. Since the trigger residence time tw is determined by the normalized distance dn, the trigger is transmitted at each timing when the dotted diagonal line illustrated in FIG. 5 intersects with the vertical line of each server.

  Even when the trigger is transmitted from the Web server A to the Web server B at the timing “2” after the trigger transmission interval td elapses from the timing “1”, each Web server transmits the trigger after the trigger residence time tw has elapsed. . Therefore, even when there are a plurality of triggers, the trigger is transmitted at a constant trigger transmission interval td.

  FIG. 6 is an explanatory diagram illustrating an example when the trigger is transmitted early and when the trigger is transmitted late. When a trigger is transmitted to the Web server C at the timing “A)” illustrated in FIG. 6, the trigger transmission prohibition time tr may be longer than the trigger residence time tw. In this case, the trigger transmission determination unit 34a waits until the trigger transmission interval td elapses (that is, the trigger transmission prohibition time becomes 0), and then instructs the trigger transmission unit 37 to transmit a trigger to the Web server D. For this reason, each Web server can maintain the trigger transmission interval td.

  On the other hand, if a trigger is transmitted to the Web server A at the timing of “B)” illustrated in FIG. 6, the trigger that arrives at the Web server A is delayed, so that the transmission of the trigger to the Web server B may also be delayed. . Therefore, the trigger transmission determination unit 34a gives the trigger transmission unit 37 a trigger transmission instruction for the Web server B after the elapse of the trigger residence time tw multiplied by the acceleration coefficient k. Similarly, since each Web server transmits a trigger after the trigger residence time tw multiplied by the acceleration coefficient k has elapsed, the trigger transmission interval is gradually reduced, so that the trigger transmission interval is set to the trigger transmission interval td. It can be converged.

  FIG. 7 is an explanatory diagram illustrating an example in which a trigger is generated according to the trigger duplication probability p (that is, a trigger copy is generated) and an example in which transmission of the trigger is suppressed. The trigger transmission determination unit 34a issues a new trigger transmission instruction at the timing of “c” illustrated in FIG. 7 according to the trigger replication probability p, for example. The subsequent processing is the same as the contents shown in FIGS. On the other hand, when a trigger is transmitted to the Web server E at the timing “d)” illustrated in FIG. 7, the trigger transmission determination unit 34a waits for a trigger transmission instruction to another Web server, or the trigger stays. The time tw may exceed the maximum allowable waiting time tw_max. At this time, the trigger transmission determination unit 34a suppresses a new trigger transmission instruction based on the received trigger, and does not perform a subsequent trigger transmission instruction. By doing in this way, the number of triggers in the loop can be kept constant (for example, the number of triggers in the loop nt).

  As described above, according to the present embodiment, the trigger transmission determination unit 34a calculates a distance (for example, normalized distance dn) from another Web server when the Web server 21a receives a trigger. The trigger residence time tw for calculating the trigger residence time tw is calculated based on the distance. The trigger transmission determination unit 34a is configured such that the trigger residence time tw is greater than the trigger transmission prohibition time tr, which is the difference between the elapsed time te from the time when the trigger is transmitted in the past to the time when the trigger is received and the trigger transmission interval td. If it is larger, it is determined that the trigger is transmitted to the Web server after the trigger residence time tw has elapsed. On the other hand, when the trigger residence time tw is equal to or shorter than the trigger transmission prohibition time tr, the trigger transmission determination unit 34a is on condition that the elapsed time te from the time when the trigger was transmitted in the past has reached the trigger transmission interval td. It is determined that a trigger is transmitted to the Web server. Then, the trigger output unit 37 transmits the trigger to another Web server based on the determination that the trigger transmission determination unit 34a transmits the trigger. Therefore, even when a source that periodically generates a trigger cannot be used, the periodic process can be executed.

  For example, when a Web server is used for constructing a DHT, a rental server that cannot use a function that periodically generates a trigger is often used for the Web server. Cannot be easily executed. In such a case, if the periodic processing execution system shown in the present embodiment is used, the periodic processing can be executed even when the Web server cannot use a source that periodically generates a trigger.

Embodiment 2. FIG.
FIG. 8 is a block diagram illustrating an example of a periodic process execution system according to the second embodiment of the present invention. In addition, about the structure similar to 1st Embodiment, the code | symbol same as FIG. 2 is attached | subjected and description is abbreviate | omitted. The regular processing execution system in this embodiment includes a Web server 21b and Web servers 22-25. The web server 21b and the web servers 22 to 25 are connected to each other via the communication network 100.

  The web server 21 b includes a communication unit 31, a trigger input unit 32, an execution unit 33, a trigger transmission determination unit 34 b, a next hop list unit 36 b, a trigger output unit 37, and a time acquisition unit 39. .

  The next hop list unit 36b stores a set of a URL of a Web server and a time when a trigger transmission instruction is given to the Web server (hereinafter referred to as a final transmission time). Specifically, the next hop list unit 36b is realized by a magnetic disk device or the like included in the Web server 21b. The next hop list unit 36b stores a predetermined number of sets of URLs and last transmission times (hereinafter referred to as a next hop list) so that the Web server is connected in a ring shape.

  FIG. 9 is an explanatory diagram illustrating an example of a network configuration in which the periodic process execution system is realized and a next hop list. In the network shown in the example of FIG. 9A, the distance between the Web servers shown on the circumference is close to the order in which they are arranged on the circumference. That is, in the example illustrated in FIG. 9A, the Web server close to the Web server A is the Web server B, and thereafter, the Web server E is sequentially arranged. In the example shown in FIG. 9B, the next hop list is created with the direction of the arrow on the circumference as the forward direction. For example, when the Web servers A to E are connected with the content illustrated in FIG. 9A, the next hop list unit 36b of the Web server A stores the next hop list with the content illustrated in FIG. 9B. To do.

  The time acquisition unit 39 calculates (acquires) the current time according to an instruction from the trigger transmission determination unit 34b and outputs the current time to the trigger transmission determination unit 34b.

  The trigger transmission determining unit 34b determines the Web server that performs the trigger transmission instruction based on the transmission time (that is, the trigger transmission time tl) instructed to transmit the trigger to the other Web server in the past. For example, the trigger transmission determination unit 34b determines to transmit a trigger to a Web server whose elapsed time from the trigger transmission time tl has reached the trigger transmission interval td. Then, the trigger transmission determination unit 34b instructs the trigger output unit 37 to transmit a trigger to the Web server.

  Specifically, the trigger transmission determination unit 34b subtracts the elapsed time te from the last transmission time stored in the next hop list unit 36b to the current time t when the trigger is received from the predetermined trigger transmission interval td. The trigger transmission inhibition time tr is calculated. Then, the trigger transmission determining unit 34b determines that a trigger transmission instruction is issued to the Web server corresponding to the final transmission time at which the trigger transmission prohibition time tr is 0 or less. That is, when the current time t is ahead of the time obtained by adding the trigger transmission interval td from the last update time, the trigger transmission determination unit 34b instructs the Web server corresponding to the last update time to send a trigger. be able to. The condition for determining that the trigger transmission determining unit 34b issues a trigger transmission instruction can be expressed by the following (Equation 1).

  Trigger transmission inhibition time tr = Trigger transmission interval td− (current time t−final transmission time) ≦ 0 (Expression 1)

  Further, (Equation 1) can be modified as the following (Equation 2).

  Last transmission time + trigger transmission interval td <current time t (Expression 2)

  This means that the current time t is ahead of the time obtained by adding the trigger transmission interval td from the last update time.

  Further, when the trigger transmission prohibition time tr is smaller than the random value R, the trigger transmission determination unit 34b may determine that a trigger transmission instruction is issued to the Web server corresponding to the final transmission time. Here, the random value R is a value smaller than the trigger transmission interval td, and is a random value determined by the trigger transmission determination unit 34b every time the trigger transmission unit calculates the trigger transmission prohibition time tr. In this case, the condition for determining that the trigger transmission determining unit 34b performs the trigger transmission instruction can be expressed by the following (Equation 3).

  Trigger transmission inhibition time tr = Trigger transmission interval td− (current time t−final transmission time) <R (Expression 3)

  Further, (Equation 3) can be modified as the following (Equation 4).

  Last transmission time + trigger transmission interval td-R <current time t (Formula 4)

  This can be said to satisfy the condition when the elapsed time from the transmission time at which the trigger was transmitted in the past has elapsed with the random value R added to the trigger transmission interval td.

  If the same time is set as the final transmission time of a plurality of nodes, the next trigger transmission to those nodes will be performed at the same time. Then, trigger transmission to a plurality of nodes is performed at the same time, which may cause overload of the Web server and concentration of access. Therefore, in the present embodiment, the final transmission time is distributed by using the random value R. Therefore, the transmission of triggers is distributed, and overload and access concentration on the Web server can be avoided.

  In the following description, the condition represented by (Expression 2) is referred to as “condition A1”, and the condition represented by (Expression 4) is referred to as “condition A2”.

  In addition, the trigger transmission determination unit 34b updates the last update time of the Web server that issued the trigger transmission instruction to the time when the trigger transmission instruction was issued, among the last update times stored in the next hop list unit 36b.

  Since the communication unit 31, the trigger input unit 32, the execution unit 33, and the trigger output unit 37 have the same configuration as in the first embodiment, description thereof is omitted.

  The configuration of the other Web servers (that is, the Web servers 22 to 25) is the same as that of the Web server 21b, and thus detailed description thereof is omitted. In the above description, the case where the periodic process execution system includes four other Web servers has been described. According to the present invention, the number of other Web servers provided in the periodic process execution system is not limited to four, and may be one or two or more.

  Note that all of the Web servers in this system do not necessarily have the same function as the Web server 21b. A plurality of Web servers corresponding to a part of the system may have the same function as the Web server 21b, or only one server in the system may have the same function as the Web server 21b. In this case, a Web server that does not have the same function as the Web server 21b may have a function of receiving a trigger and transmitting the trigger to another device. For this reason, other Web servers may not have the function of adjusting the time interval (that is, the trigger transmission determination unit 34b and the time acquisition unit 39). Since more servers in the system have the same function as the Web server 21b (that is, the function of adjusting the time interval), it can be said that it is more preferable because the accuracy of the regular processing is increased.

  The communication unit 31, the trigger input unit 32, the execution unit 33, the trigger transmission determination unit 34b, the trigger output unit 37, and the time acquisition unit 39 are performed by a CPU of a computer that operates according to a program (periodic process execution program). Realized. For example, the program is stored in a storage unit (not shown) of the Web server 21b, and the CPU reads the program, and according to the program, the communication unit 31, the trigger input unit 32, the execution unit 33, the trigger transmission determination unit 34b, The trigger output unit 37 and the time acquisition unit 39 may operate. Further, the communication unit 31, the trigger input unit 32, the execution unit 33, the trigger transmission determination unit 34b, the trigger output unit 37, and the time acquisition unit 39 may be realized by dedicated hardware. Good. In addition, the communication unit 31 may be realized by a CPU of a computer that operates according to a program that realizes a general Web server service.

  Next, the operation will be described. FIG. 10 is a flowchart illustrating an example of processing until the trigger transmission determination unit 34 b issues a trigger transmission instruction to the trigger output unit 37 in response to an instruction from the trigger input unit 32. In the following description, it is assumed that the determination as to whether or not the trigger transmission determination unit 34b issues a trigger transmission instruction is based on “Condition A2”.

  When the Web server 21b receives the trigger, the trigger transmission determination unit 34b selects one of the URLs corresponding to the last transmission time that satisfies the “condition A2” (step S31). For example, the trigger transmission determination unit 34b may select the URL corresponding to the earliest last transmission time among the URLs that satisfy the conditions, but the method by which the trigger transmission determination unit 34b selects the URL is limited to the above method. Not. Hereinafter, the selected URL is referred to as URLs. The trigger transmission determination unit 34b instructs the trigger transmission unit 37 to transmit a trigger to the Web server specified by URLs. In addition, the trigger transmission determination unit 34b updates the last update time corresponding to the URLs among the last update times stored in the next hop list unit 36b to the time when the trigger transmission instruction is issued (step S32).

  The trigger transmission determination unit 34b determines whether there is another URL corresponding to the final transmission time that satisfies the “condition A2” (step S33). If there is another URL corresponding to the final transmission time that satisfies “condition A2” (YES in step S33), the trigger transmission determination unit 34b repeats the processing from step S31 onward. On the other hand, when there is no other URL corresponding to the final transmission time that satisfies “condition A2” (NO in step S33), the trigger transmission determination unit 34b ends the process.

  An operation in which the trigger transmission determination unit 34b transmits a trigger to another Web server will be described using another example. FIG. 11 is an explanatory diagram illustrating an example of an operation in which each Web server transmits a trigger. In the example illustrated in FIG. 11, A to E indicate Web servers, and each Web server transmits a trigger in the direction of the arrow.

  First, when a trigger is transmitted to the Web server A (step S41), the trigger transmission determination unit 34b of the Web server A determines a Web server that transmits the trigger based on a condition (for example, condition A1). . For example, when only the Web server B satisfies the condition, the trigger transmission determination unit 34b of the Web server A determines to transmit a trigger to the Web server B, and the trigger output unit 37 transmits the trigger to the Web server B ( Step S42). When the trigger is transmitted to the Web server B, the trigger transmission determination unit 34b of the Web server B determines the Web server that transmits the trigger based on the condition. For example, when only the Web server D satisfies the condition, the trigger transmission determination unit 34b of the Web server B determines to transmit a trigger to the Web server D, and the trigger output unit 37 transmits the trigger to the Web server D ( Step S43).

  Similarly, when a trigger is transmitted to the Web server D and the only Web server that satisfies the condition is the Web server earlier than the Web server E, the trigger transmission determination unit 34b of the Web server D determines that the Web server E is a Web server earlier than the Web server E. The trigger output unit 37 transmits a trigger to the Web server (step S44).

  On the other hand, when the trigger is transmitted again to the Web server A (step S45), the trigger transmission determination unit 34b of the Web server A determines the Web server that transmits the trigger based on the condition. For example, when the Web server B that recently transmitted the trigger does not satisfy the condition and only the Web server C satisfies the condition, the trigger transmission determination unit 34b of the Web server A determines to transmit the trigger to the Web server C, and the trigger output unit 37 transmits a trigger to the Web server C (step S46). Similarly, when a trigger is transmitted to the Web server C and the only Web server that satisfies the condition is the Web server D, the trigger transmission determination unit 34b of the Web server C determines to transmit a trigger to the Web server D, and trigger output The unit 37 transmits a trigger to the Web server D (Step S47). If the trigger is transmitted to the Web server D and the only Web server that satisfies the condition is the Web server E, the trigger transmission determination unit 34b of the Web server D determines that the trigger is transmitted to the Web server E, and the trigger output unit 37 transmits a trigger to the Web server E (step S48). When a trigger is transmitted to the Web server E, and the only Web server that satisfies the condition is the Web server before the Web server E, the trigger transmission determination unit 34b of the Web server E triggers the trigger to the Web server before the Web server E. The trigger output unit 37 determines to transmit, and transmits a trigger to the Web server (step S49).

  When a trigger is transmitted to Web server B from before Web server A (step S50), trigger transmission determination unit 34b of Web server B determines the Web server that transmits the trigger based on the conditions. . For example, when the Web server D that recently transmitted the trigger does not satisfy the condition and only the Web server C satisfies the condition, the trigger transmission determination unit 34b of the Web server B determines to transmit the trigger to the Web server C, and the trigger output unit 37 transmits a trigger to the Web server C (step S51). Similarly, when a trigger is transmitted from the Web server B to the Web server C, and the Web server D that recently transmitted the trigger does not satisfy the condition, and only the Web server E satisfies the condition, the trigger transmission determination unit of the Web server C 34b determines to transmit a trigger to the Web server E, and the trigger output unit 37 transmits the trigger to the Web server E (step S52). Further, a trigger is transmitted to the Web server E, and it is determined that the Web server that satisfies the condition is a Web server earlier than the Web server E and the trigger is transmitted to a Web server that has not recently transmitted a trigger, The trigger output unit 37 transmits a trigger to the Web server (step S49).

  As described above, when a large number of trigger transmission instructions are issued to one Web server, the trigger transmission is interrupted because there is no fixed interval since the last trigger transmission instruction is issued, so the trigger transmission instructions are reduced. To do. Conversely, when there are few trigger transmission instructions given to one Web server, the trigger transmission instruction is issued to a plurality of nodes since a predetermined interval has passed since the previous trigger transmission instruction was issued. Therefore, the number of trigger transmission instructions to be issued throughout the network is kept constant.

  As described above, according to the present embodiment, triggered by the Web server 21b receiving a trigger, the trigger transmission determination 34b is from the last update time among the Web servers stored in the next hop list unit 36b. It is determined that the trigger is transmitted to the Web server whose elapsed time (for example, current time t−final transmission time) has reached the trigger transmission interval td. Then, the trigger output unit 37 transmits the trigger to another Web server based on the determination that the trigger transmission determination unit 34b transmits the trigger. Therefore, even when a source that periodically generates a trigger cannot be used, the periodic process can be executed.

  According to the periodic process execution system of the present invention, the DHT maintenance process can be realized even in a system using a rental server in which the use of cron or the permanent startup of a process is restricted. Note that the process of applying the periodic process execution system according to the present invention is not limited to the case of performing the DHT maintenance process. For example, the same applies to other cases in which a process is periodically executed by starting a daemon. Applicable.

  For example, it can be applied to DNS (Domain Name System). By applying this system, processing such as associating a host name with an IP (Internet Protocol) address (hereinafter referred to as DNS maintenance processing) can be periodically executed based on an instruction from a DNS server. A trigger for causing another DNS server to execute the DNS maintenance process can be transmitted periodically.

  In addition, for example, the present invention can be applied to a case where update information of a blog that the user wants to browse is collected periodically. In general, in order for a user to periodically collect blog update information, it is necessary to activate a daemon on a computer used by the user and periodically update the information using the daemon. However, according to the present system, RSS (Resource description framework Site Summary) information in the computer can be periodically updated based on an instruction from a server that manages the blog.

  Furthermore, for example, the present invention can also be applied to managing files distributed on a network using DHT. When each server that manages files receives the update information of the server that manages other files, it updates the management information in its own server, and notifies the update information after adjusting the transmission interval to other servers. can do.

  In addition, it can be said that the periodic process execution device and the periodic process execution system as described below are also described in any of the embodiments described above.

(1) When a trigger for executing a periodic process is received from an external device, the time when the trigger was transmitted in the past to an external device that is a trigger transmission target (for example, trigger transmission time tl, On the condition that the elapsed time from the last transmission time (for example, elapsed time te, current time t−final transmission time) has reached a predetermined trigger transmission interval (for example, trigger transmission interval td), the external Trigger transmission determination means (for example, trigger transmission determination units 34a and 34b) that determines that a trigger is transmitted to the device of the above, and an external device (for example, A periodic processing execution apparatus comprising trigger transmission means (for example, a trigger output unit 37) for transmitting a trigger to another Web server.

(2) distance calculation means (for example, trigger transmission determination unit 34a) for calculating a distance (for example, normalized distance dn) with an external device that transmits a trigger to a periodic process execution device (for example, Web server 21a); A residence time calculating unit (for example, trigger transmission determining unit 34a) that calculates a residence time (for example, trigger residence time tw) that is a time for which the transmission of the trigger is retained, based on the distance, If the residence time is longer than the transmission prohibition time (for example, the trigger transmission prohibition time tr), which is the difference between the elapsed time from the time when the trigger is transmitted to the time when the trigger is received and the trigger transmission interval, Elapsed from the time the trigger was sent in the past if it is determined that the trigger will be sent to an external device after the residence time has elapsed and the residence time is less than the transmission prohibition time During the condition that has reached the trigger transmission interval, periodic processing execution unit determines to transmit a trigger to an external device.

(3) A periodic processing execution device in which the residence time calculation means calculates the residence time by multiplying the residence time by a coefficient (for example, an acceleration coefficient k) for shortening the residence time.

(4) A device information storage unit (for example, a next hop list unit 36a) that stores a plurality of device information (for example, URLs) that can specify a device that is a transmission target candidate of the trigger is provided, A periodic processing execution device that transmits a trigger to a device that is different from the device and that is specified by the device information stored in the device information storage means when the transmission of the device fails.

(5) Based on a predetermined probability (for example, trigger replication probability p), the trigger transmission determination unit determines to transmit a trigger to any device specified by the device information stored in the device information storage unit Regular processing execution device.

(6) A transmission time storage unit (for example, trigger transmission determination unit 34b) that stores a transmission time when the trigger transmission unit transmits a trigger in the past to a device that is a transmission target candidate of the trigger in association with the device. A periodic processing execution device that determines that the trigger transmission determination unit transmits a trigger to a device that has elapsed from the transmission time and has reached the trigger transmission interval among the devices stored in the transmission time storage unit.

(7) Random interval determination means (for example, trigger) that determines a random time interval (for example, random value R) that is a random value smaller than the transmission interval each time the trigger transmission determination means determines whether or not to transmit a trigger. A transmission determination unit 34b), wherein the trigger transmission determination means transmits a trigger to an apparatus in which the elapsed time from the transmission time at which the trigger was transmitted in the past has elapsed by adding a random time interval to the trigger transmission interval. A periodic processing execution device that determines that this is the case.

(8) A periodic process execution device including execution means (for example, the execution unit 33) that executes a periodic process when a trigger is received.

(9) A plurality of external devices (for example, Web servers 22 to 25) that transmit a trigger for executing periodic processing, and a periodic processing execution device (for example, Web server) that causes the external devices to periodically execute processing 21a, b), and the time at which the periodic process execution device has transmitted the trigger to the external device that is the trigger transmission target in response to the reception of the trigger from the external device (for example, the trigger transmission time) tl, the last transmission time) (for example, elapsed time te, current time t-final transmission time) on condition that the predetermined trigger transmission interval (for example, trigger transmission interval td) has been reached. Trigger transmission determination means (for example, trigger transmission determination units 34a and 34b) that determines that a trigger is transmitted to the external device, and trigger transmission determination means transmit the trigger. Based on that determination the periodic processing execution system, characterized in that it includes a trigger transmitting unit configured to transmit a trigger to an external device (e.g., a trigger output unit 37).

(10) Distance calculation means (for example, trigger transmission determination unit 34a) for calculating a distance (for example, normalized distance dn) with an external device that transmits a trigger to the periodic process execution device, and a time for which the trigger transmission is held A dwell time calculating means (for example, trigger transmission determining unit 34a) for calculating a certain dwell time (for example, trigger dwell time tw) based on the distance, and the trigger transmission determining means from the time when the trigger was transmitted in the past to this time When the residence time is longer than the transmission prohibition time (for example, the trigger transmission prohibition time tr) that is the difference between the elapsed time up to the time when the trigger is received and the trigger transmission interval, the external device If the residence time is less than the transmission prohibition time, the elapsed time from the time the trigger was sent in the past has reached the trigger transmission interval. On condition Rukoto, periodic process execution system determines to transmit a trigger to an external device.

(11) The distance calculation means is an identifier for identifying each device, and the distance from each device based on an identifier (for example, an ID based on a code (Chord)) that forms a loop with the entire identifier. The periodic processing execution system in which the trigger transmission means transmits the trigger to the external device closest to the distance.

(12) The external device and the periodic processing execution device (for example, each Web server) form a ring-shaped network, and the trigger transmission means sequentially triggers another device (for example, another Web server) along the network. A periodic processing execution system that sends

(13) A transmission time storage unit (for example, trigger transmission determination unit 34b) that stores a transmission time when the trigger transmission unit transmits a trigger in the past to a device that is a transmission target candidate of the trigger in association with the device. A periodic processing execution system for determining that the trigger transmission determination unit transmits a trigger to a device whose elapsed time from the transmission time has reached the trigger transmission interval among the devices stored in the transmission time storage unit.

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the above embodiments and examples. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  This application claims the priority on the basis of the JP Patent application 2009-126841 for which it applied on May 26, 2009, and takes in those the indications of all here.

  The present invention is preferably applied to a periodic processing execution system that periodically executes processing.

21a, 21b, 22-25 Web server 31 communication unit 32 trigger input unit 33 execution unit 34a, 34b trigger transmission determination unit 35 trigger transmission time management unit 36a, 36b next hop list unit 37 trigger output unit 38 trigger transmission time storage unit 39 Time acquisition unit 100 Communication network

Claims (19)

Trigger transmission with a predetermined elapsed time from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target, triggered by the reception of the trigger for executing the periodic processing from the external device Trigger transmission determination means for determining that a trigger is transmitted to the external device on the condition that the interval has been reached;
A periodic processing execution device comprising: a trigger transmission unit configured to transmit a trigger to the external device based on the determination that the trigger transmission determination unit transmits a trigger. Distance calculating means for calculating a distance from an external device that transmits a trigger to the periodic processing execution device;
A dwell time calculation means for calculating a dwell time that is a dwell time of transmission of the trigger based on the distance;
The trigger transmission determination means determines that the staying time is longer when the staying time is longer than the transmission prohibition time that is the difference between the elapsed time from the time when the trigger is transmitted to the time when the trigger is received and the trigger transmission interval. It is determined that a trigger is transmitted to an external device after a lapse of time, and when the stay time is equal to or shorter than the transmission prohibition time, the elapsed time from the time when the trigger was transmitted in the past has reached the trigger transmission interval. The periodical processing execution device according to claim 1, wherein it is determined that a trigger is transmitted to an external device on the condition of. The periodic processing execution device according to claim 2, wherein the residence time calculation means calculates the residence time by multiplying the residence time by a coefficient for reducing the residence time. Device information storage means for storing a plurality of device information capable of specifying devices that are trigger transmission candidates,
The trigger transmission unit transmits a trigger to a device that is different from the device and is specified by device information stored in the device information storage unit when transmission of a trigger to the device fails. The periodic process execution device according to any one of claims 1 to 3. The periodic processing execution device according to claim 4, wherein the trigger transmission determination unit determines to transmit the trigger to any device specified by the device information stored in the device information storage unit based on a predetermined probability. A transmission time storage means for storing a transmission time when the trigger transmission means transmits a trigger in the past for a device that is a transmission target candidate of the trigger in association with the device, and
2. The periodic transmission according to claim 1, wherein the trigger transmission determination unit determines to transmit a trigger to a device whose elapsed time from the transmission time has reached a trigger transmission interval among the devices stored in the transmission time storage unit. Processing execution device. Random interval determination means for determining a random time interval that is a random value smaller than the transmission interval each time the trigger transmission determination means determines whether to transmit a trigger,
The trigger transmission determining means determines that the trigger is transmitted to a device whose elapsed time from the transmission time at which the trigger was transmitted in the past has elapsed with the random time interval added to the trigger transmission interval. Regular processing execution device. The periodic processing execution device according to any one of claims 1 to 7, further comprising execution means for executing periodic processing when a trigger is received. A plurality of external devices that transmit triggers for executing periodic processing;
A periodic processing execution device that periodically executes processing on an external device;
The periodic process execution device includes:
When the trigger is received from the external device, the elapsed time from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target has reached a predetermined trigger transmission interval. Trigger transmission determination means for determining that a trigger is transmitted to the external device as a condition,
A periodic processing execution system comprising: a trigger transmission unit that transmits a trigger to the external device based on the determination that the trigger transmission determination unit transmits a trigger. A distance calculating means for calculating a distance from an external device that transmits a trigger to the periodic processing execution device;
A dwell time calculation means for calculating a dwell time that is a dwell time of transmission of the trigger based on the distance;
The trigger transmission determination means determines that the staying time is longer when the staying time is longer than the transmission prohibition time that is the difference between the elapsed time from the time when the trigger is transmitted to the time when the trigger is received and the trigger transmission interval. It is determined that a trigger is transmitted to an external device after the elapse of time, and when the stay time is equal to or shorter than the transmission prohibition time, the elapsed time from the time when the trigger was transmitted in the past has reached the trigger transmission interval. The periodic processing execution system according to claim 9, wherein it is determined that a trigger is transmitted to an external device as a condition. The distance calculation means is an identifier for identifying each device, and calculates a distance from each device based on an identifier that forms a loop with the entire identifier,
The regular processing execution system according to claim 9 or 10, wherein the trigger transmission unit transmits a trigger to an external device having the closest distance. The external device and the periodic processing execution device form a ring network,
The periodic processing execution system according to any one of claims 9 to 11, wherein the trigger transmission unit sequentially transmits a trigger to another device along the network. A transmission time storage means for storing a transmission time when the trigger transmission means transmits a trigger in the past for a device that is a transmission target candidate of the trigger in association with the device, and
10. The periodic transmission determination unit according to claim 9, wherein the trigger transmission determination unit determines to transmit a trigger to a device whose elapsed time from the transmission time has reached a trigger transmission interval among the devices stored in the transmission time storage unit. Processing execution system. Trigger transmission with a predetermined elapsed time from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target, triggered by the reception of the trigger for executing the periodic processing from the external device It is determined that a trigger is transmitted to the external device on the condition that the interval has been reached,
A periodic processing execution method, comprising: transmitting a trigger to the external device based on determining that a trigger is to be transmitted. Calculate the distance to the device that sends the trigger from the outside,
Based on the distance, the residence time, which is the time for which the transmission of the trigger is retained, is calculated.
When determining whether to send a trigger to an external device, than the transmission prohibition time, which is the difference between the elapsed time from the time when the trigger was transmitted in the past to the time when the trigger was received and the trigger transmission interval, When the stay time is greater, it is determined that a trigger is transmitted to an external device after the stay time has elapsed, and when the stay time is equal to or shorter than the transmission prohibition time, the trigger is transmitted in the past. The periodical process execution method according to claim 14, wherein it is determined that a trigger is transmitted to an external device on the condition that the elapsed time has reached the trigger transmission interval. When determining whether or not to transmit a trigger to an external device, the device is stored in a transmission time storage unit that stores a device that is a trigger transmission target candidate and a transmission time at which the trigger is transmitted to the device in association with each other. The periodic processing execution method according to claim 14, wherein among the devices that have been transmitted, a trigger is determined to be transmitted to a device whose elapsed time from the transmission time has reached a trigger transmission interval. On the computer,
Trigger transmission with a predetermined elapsed time from the time when the trigger was transmitted in the past to the external device that is the trigger transmission target, triggered by the reception of the trigger for executing the periodic processing from the external device Trigger transmission determination processing for determining that a trigger is transmitted to the external device on the condition that the interval has been reached; and
A periodic process execution program for causing a trigger transmission process to transmit a trigger to the external device based on the determination that a trigger is transmitted in the trigger transmission determination process. On the computer,
Distance calculation processing for calculating the distance to the device that transmits the trigger from the outside, and
A dwell time calculation process for calculating a dwell time that is a dwell time of the trigger based on the distance is executed,
In the trigger transmission determination process, if the stay time is larger than the transmission prohibition time that is the difference between the trigger transmission interval and the elapsed time from the time when the trigger was transmitted in the past to the time when the trigger was received, When the trigger is transmitted to an external device after the elapse of time and the stay time is equal to or shorter than the transmission prohibition time, the elapsed time from the time when the trigger was transmitted in the past has reached the trigger transmission interval. The periodic processing execution program according to claim 17, wherein the program determines that a trigger is to be transmitted to an external device on the condition. A periodic processing execution program applied to a computer having a transmission time storage means for storing a transmission time when a trigger transmission means has transmitted a trigger in the past to a device that is a transmission target candidate of the trigger in association with the device. There,
In the computer,
The periodic transmission according to claim 17, wherein the trigger transmission determination process determines that a trigger is transmitted to a device whose elapsed time from the transmission time has reached a trigger transmission interval among the devices stored in the transmission time storage means. Processing execution program.

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