JP6102409B2 - Event processing method, event processing system, and event processing program - Google Patents

Description

  The embodiments discussed herein relate to event processing using stream computing.

  With increasing demand for faster business decisions, stream computing has attracted attention. Stream computing is a technology for processing in real time a large number of events collected from various sensors and systems (data collected by sensing or data generated by the system, and data itself). In conventional data processing, collected events are temporarily stored in a database, a query is issued, and data in a condition is extracted and analyzed. On the other hand, in stream computing, logic for detecting an event is given as a query to the stream engine in advance, and the query is executed when the event arrives to extract and analyze the event. For this reason, it is used for algorithmic trading, factory facility operation status monitoring, and fraud detection of system operation.

  On the other hand, with the widespread use of mobile terminals equipped with various sensors and the development of wireless technology, the status of mobile objects (people and things that accompany movement) can be grasped, and services that respond to changes in the status of mobile objects are attracting attention. ing. For example, collect location information from a person's mobile terminal and distribute optimal content according to the person's whereabouts, or carry a sensor to an outpatient to monitor whether they have entered an unauthorized area. Service is considered. For this purpose, it is necessary to collect events by wireless distribution and process them in real time, and stream computing is being applied to mobile environments.

  Usually, the wireless environment is unstable, and communication is impossible due to various environmental factors, and the mobile terminal may not be able to transmit collected events to a server on which the stream engine operates. Since the stream engine processes events continuously, if an event is missing, there is a possibility that the event cannot be processed correctly. For example, because the human movement trajectory is incomplete, the prediction accuracy of the next destination will decrease, so it will not be possible to send appropriate content in advance, or it will not be possible to detect an event that has entered the restricted area for a certain period of time, It is conceivable that the unauthorized entry determination may fail.

  In order to solve such a problem, there is a method of holding events collected on the terminal side when the terminal is offline, and transmitting the held event to the stream engine when the terminal is online ( (See FIG. 2). By doing so, it is possible to cause the stream engine to sequentially process all events collected by the mobile terminal.

JP 2010-154514 A

  However, the stream engine is based on the premise that the difference between the event occurrence time and the arrival time is small, and there is a problem that correct processing cannot be performed if the time for the event arrival at the stream engine is greatly delayed from the occurrence time. For example, typical processing of the stream engine includes timer processing and time window processing. The timer process is a process for detecting that a predetermined event has not arrived or has arrived within a certain time after a certain event has arrived. The time window process is a process for buffering events that arrive within a certain period and performing a common process (for example, obtaining an average value or a maximum value). Since these processes are performed based on the arrival time of the event to the stream engine, if the difference between the event occurrence time and the arrival time is large, a timer event cannot be generated at a predetermined time, or time window processing The target event may not be recognized correctly.

  Therefore, it is a problem to correctly perform stream processing for an event having a large difference between the generation time and the arrival time to the system.

  In the event processing method described later in this specification, the following processing is executed by a computer. First, the connection state of a terminal that transmits data collected by the sensor as event data to the event processing system is monitored. Next, the cumulative value of the time during which the terminal cannot communicate is calculated. When stream processing is performed, a correction time is calculated by subtracting the accumulated value from the system clock time. Finally, the event data transmitted by the terminal is stream-processed based on the correction time and output.

  According to the event processing system described later in this specification, it is possible to correctly perform stream processing on an event having a large difference between the generation time and the arrival time at the system.

It is a block diagram of one Example of an event processing system. It is a figure for demonstrating the method of transmitting the event to a stream engine when it assumes that a terminal will be offline. It is a figure for demonstrating the timeline of event processing. It is a lineblock diagram of the event processing system concerning a 1st embodiment. It is a block diagram which shows an example of the hardware constitutions of a standard computer. It is a figure for demonstrating the example of a terminal state management table. It is the flowchart which illustrated the processing content of the session start process. It is the flowchart which illustrated the processing content of the terminal connection state monitoring process. It is the flowchart which illustrated the processing content of event stream reproduction | regeneration processing. It is a block diagram of the event processing system which concerns on 2nd Embodiment.

<Configuration of event processing system>
FIG. 1 is a configuration diagram of an event processing system for explaining the principle of the present invention. As shown in FIG. 1, the event processing system 10 includes a terminal connection state monitoring unit 11, a clock correction unit 12, an event stream reproduction unit 13, a stream engine 14, and a system clock 15.

  The terminal 50 includes a sensor 51. The terminal 50 transmits the sensor data collected by the sensor 51 to the event processing system 10 as event data.

  The terminal connection status monitoring unit 11 monitors the connection status of whether each terminal 50 can communicate (online) or not (offline).

  The clock correction unit 12 calculates and manages the time of going offline for each terminal 50 and the accumulated value of the offline time, and the event stream playback unit 13 and the stream engine 14 keep the terminal 50 online. Provide the time of day (apparent time).

  The event stream reproduction unit 13 inputs the event data transmitted from the terminal 50 to the stream engine 14 at the time when it should originally arrive.

  The stream engine 14 processes the event and outputs the event to the event use service 60.

  The system clock 15 is a clock that always operates at a constant speed provided by a device or OS that operates the event processing system 10 and provides an actual time.

  With such a configuration, the event processing system 10 controls the clock correction unit 12 referred to by the stream engine 14 and goes online so that the clock is stopped while the terminal 50 that transmits the event is offline. An event that arrives late can be recognized by the stream engine 14 as if it had arrived now.

  Further, the event processing may be performed efficiently by processing the interval between events transmitted offline while making the interval shorter than the actual time, that is, by making the apparent time advance faster.

<Operation of event processing system>
Next, an event processing method in the event processing system 10 will be described. The event processing method is executed by a computer.

FIG. 2 is a diagram for explaining a method of transmitting an event to the stream engine when the terminal is assumed to be offline. The normal operation causes the computer to execute the following two types of processing by a program.
(1) Terminal connection status monitoring process (2) Event stream playback process

  The operation of the terminal connection state monitoring process is as follows. The terminal connection state monitoring unit 11 monitors the connection state (online or offline) of the terminal 50, and notifies the clock correction unit 12 of the terminal identifier and the contents of the state change when the connection state changes. The clock correction unit 12 calculates and manages the time when the terminal 50 goes offline for each terminal 50 and the accumulated value of the offline time (hereinafter sometimes referred to as accumulated offline time), and the terminal 50 goes from online to offline. In the case of a change, the difference between the time when the change was made offline and the system clock 15 is calculated and added to the accumulated offline time so far to obtain a new accumulated offline time. By doing so, it is possible to grasp the accumulated time that each terminal has been offline from the initial state to the present.

  The operation of the event stream playback process is as follows. The terminal 50 transmits an event to the event processing system 10. At this point, the terminal 50 is online, and sensor data collected by the sensor 51 may be transmitted in real time, or an event collected while offline may be transmitted. Each event has, in addition to the sensor data, the time when the sensor data is collected and the identifier of the terminal 50 as attributes (the clock of the terminal 50 is assumed to be synchronized with the system clock 15 of the event processing system 10). Events collected while the terminal 50 is offline may be transmitted one by one in sequence or may be transmitted all at once. The event transmitted from the terminal 50 is passed to the event stream playback unit 13. The event stream reproduction unit 13 refers to the data collection time included in each event and the identifier of the terminal 50, and acquires the apparent time of the terminal 50 from the clock correction unit 12 using the terminal identifier as a key. The clock correction unit 12 refers to the system clock 15 and acquires the time of the terminal 50 from the clock correction unit 12 using the terminal identifier as a key. The clock correction unit 12 refers to the system clock 15 and returns a correction time obtained by subtracting the accumulated offline time updated as needed by the terminal connection state monitoring process. This indicates the time at which the event should originally arrive. The event stream reproduction unit 12 inputs each event to the stream engine 14 at the time when the event should arrive originally. While the stream engine 14 processes the event, the clock is referred to. The correction value considering the offline time for each terminal 50 is also used via the clock correction unit 12 at that time. In addition, when the terminal 50 is offline, the events that are supposed to be replied are stagnant, and the apparent time referred to by the stream engine 14 always returns the time when the terminal 50 is offline. At this time, the event processing may be performed efficiently by processing the interval of the event transmitted while offline, shorter than the actual interval.

  FIG. 3 is a timeline showing this operation. Events collected and transmitted while the terminal 50 is online (events collected at times t0 and t1) are immediately passed to the stream engine 14 and processed by the event stream playback unit 13. When the terminal 50 goes offline at time Toff, the terminal 50 collects events (collects events at times t2 and t3), but cannot transmit to the event processing system 10. Then, the clock referred to by the stream engine 14 always refers to the time when it goes offline, and timer processing and time window processing are also stopped. When the terminal 50 returns online at the time Ton, the events at the times t2 and t3 collected while offline are transmitted to the event processing system 10. However, the event stream playback unit 13 does not immediately pass to the stream engine 14, but waits until the actual time becomes t2 + (Ton-Toff) and t3 + (Ton-Toff). Ton-Toff is the time when the terminal 50 has been offline. The stream engine (4) performs processing while referring to the correction time obtained by subtracting the time from the actual time, so that the event is originally It can be processed as occurring at times t2 and t3. The event at time t4 collected after the terminal 50 returns online is processed in the same manner.

  In the event processing system 10, the terminal connection state monitoring unit 11 monitors the connection status of the terminal 50 and notifies the clock correction unit 12 of the monitoring. The clock correction unit 12 calculates and manages the cumulative value of whether the terminal 50 is offline or online, and the time that has been offline. Then, when other modules refer to the time, it is assumed that the terminal 50 has always sent an event in an online state by returning a correction time obtained by subtracting the accumulated offline time from the actual time, that is, the time of the system clock. Be able to provide the time of the case. When the terminal 50 is offline, the events that should have arrived are stagnant, so that the apparent time when the terminal 50 is offline is returned so that the time does not advance.

  By operating in this way, when processing an event, the event stream playback unit 13 can use the clock correction unit 12 to input the event to the stream engine 14 as if the event has just arrived. The stream engine 14 can operate as if it is processing the current event. Therefore, even if the event occurrence time and arrival time are significantly different, the stream engine 14 can process normally.

<First Embodiment>
FIG. 4 is a configuration diagram of the event processing system according to the first embodiment. The event processing system 20 collects events from the terminal 50 by wireless communication. In FIG. 4, similar numbers are assigned to the elements shown in FIG.

  As shown in FIG. 4, the event processing system 20 is similar to the event processing system 10 in that the terminal connection state monitoring unit 21, the clock correction unit 22, the event stream playback unit 23, the stream engine 24, and the system clock 25 are displayed. And a session management unit 26 and an event reception unit 27.

  The terminal connection state monitoring unit 21, the clock correction unit 22, the event stream reproduction unit 23, the stream engine 24, and the system clock 25 operate in the same manner as the event processing system 10.

  The session management unit 26 authenticates the terminal 50 that requested the session start as necessary, starts the session, acquires the time from the system clock 25, and returns it to the terminal 50. Furthermore, the session management unit 26 notifies the terminal connection state monitoring unit 21 of the start of the session together with the ID of the terminal 50.

  The event receiver 27 analyzes the event transmitted from the terminal 50, converts it into an internal format, and passes it to the event stream playback unit 23.

  Here, the operation of the event processing system according to the above embodiment and an example of a computer that is commonly applied to cause a computer to perform event processing will be described.

  FIG. 5 is a block diagram illustrating an example of a hardware configuration of a standard computer. As shown in FIG. 5, a computer 70 includes a central processing unit (CPU) 71, a memory 72, an input device 73, an output device 74, an external storage device 76, a medium drive device 77, a network connection device 79, and the like via a bus 75. Are connected to each other.

  The CPU 71 is an arithmetic processing unit that controls the operation of the entire computer 70. The CPU 71 uses the memory 72 to execute the event processing program, whereby the terminal connection state monitoring unit 21, the clock correction unit 22, the event stream reproduction unit 23, the stream engine 24, the session management unit 26, and the event reception shown in FIG. The unit 27 operates.

  The memory 72 includes, for example, a random access memory (RAM) and a read only memory (ROM), and stores an event processing program and data used for event processing. The memory 72 is a storage unit for storing an event processing program in advance or using it as a work area as necessary when the event processing program is executed. For example, the memory 72 can also be used as a storage unit that stores the time when each terminal 50 is offline and the accumulated offline time.

  The input device 73 is a device that, when operated by a computer user, acquires various information inputs from the user associated with the operation content and transmits the acquired input information to the CPU 71. Keyboard device, mouse device, etc. The input device 73 receives an editing operation input from an external input when executing the event processing program.

  The output device 74 is a device that outputs a processing result by the computer 70, and includes a display device and the like. The display device is, for example, a display, a printer, or the like, and is used for outputting an inquiry to a computer user, a processing result, and the like. For example, the display device displays text and images according to display data sent by the CPU 71. The output device 74 outputs an event when executing the event processing program.

  The external storage device 76 is a storage device such as a hard disk, for example, and stores various control programs executed by the CPU 71, acquired data, and the like. Examples of the storage device include a magnetic disk device, an optical disk device, and a magneto-optical disk device. The external storage device 76 can also store the time when each terminal 50 has gone offline and the respective accumulated offline time. In this case, the time of going offline for each terminal 50 and each accumulated offline time are read from the external storage device 76 to the memory 72 and used for event processing. Furthermore, the event processing program can be stored in the external storage device 76 of the computer 70 and loaded into the memory 72 for use as required.

  The medium driving device 77 is a device for writing to and reading from the portable recording medium 78. The medium driving device 77 drives the portable recording medium 78 and accesses the recorded contents.

  The CPU 71 can also perform event processing by reading and executing the event processing program recorded on the portable recording medium 78 via the medium driving device 77. The portable recording medium 78 is, for example, a Compact Disc (CD) -ROM, a Digital Versatile Disc (DVD), a Universal Serial Bus (USB) memory, or the like.

  The network connection device 79 is an interface device that manages transmission / reception of various data performed between the outside by wired or wireless. The network connection device 79 communicates with an external device via an arbitrary network (line) such as a local area network (LAN) or a wide area network (WAN), and performs data conversion accompanying the communication. If necessary, the event processing program can be received from an external device and loaded into the memory 72 of the computer 70 for use.

  The bus 75 is a communication path for connecting the above devices and the like to exchange data. The above-mentioned program can be stored in the portable recording medium 78 and loaded into the memory 72 of the computer 70 for use as necessary.

  An event processing program that causes a computer to execute the event processing according to each of the above embodiments is stored in, for example, the external storage device 76. The CPU 71 reads an event processing program from the external storage device 76 and performs event processing. At this time, an event processing program for causing the CPU 71 to perform event processing is stored in the external storage device 76 in advance. Then, a predetermined instruction is given to the CPU 71 from the input device 73, and this event processing program is read from the external storage device 76 and executed. The event processing program may be stored in the portable recording medium 78.

Next, an example of loading an event processing program and data to the computer 70 shown in FIG. 5 will be described.
In order for the computer 70 to perform the function corresponding to the event processing system 20 described in the above embodiment, the event processing program is stored in advance in the portable recording medium 78 that can be read by the computer 70. Then, the event processing program is read from the portable recording medium 78 to the computer 70 and temporarily stored in the memory 72 or the external storage device 76 of the computer 70, and the stored event processing program is included in the computer 70. The CPU 71 may be configured to read and execute.

  Further, the event processing program may be downloaded from the database of the server to the computer 70 via the network.

<Operation phase of the entire system>
Next, the event processing method in this embodiment will be described. A typical operation phase of the entire system including the terminal 50 is as follows. The computer executes these processes.
(1) The terminal 50 starts a session for event transmission and starts sensing.
(2) The terminal 50 comes online and transmits the collected sensor data to the event processing system 20 as an event.
(3) The terminal 50 goes offline and accumulates events in the terminal 50.
(4) The terminal 50 goes online and transmits the events accumulated while offline to the event processing system.
(Repeat (3) to (4).)
(5) The terminal ends sensing and ends the session for event transmission.

The event processing system has the following four types of operations.
Session start processing (corresponding to operation phase (1)): FIG. 6 shows an example of a terminal state management table. FIG. 7 is a flowchart illustrating the processing contents of the session start processing.
In S <b> 100, the terminal 50 requests the session management unit 26 to start a session before transmitting an event to the event processing system 20. The session may be any session as long as it is constantly maintained while the event is continuously sent, and may be a session such as Virtual Private Network (VPN) or Hypertext Transfer Protocol (HTTP).

  In S102, the session management unit 26 performs authentication as necessary and starts a session. Next, in S <b> 104, the session management unit 26 acquires the time from the system clock 25 and returns it to the terminal 50.

  In S106, the terminal 50 sets the clock of the terminal 50 to the acquired time. Further, in S108, the terminal 50 starts collecting and transmitting events and continues until the session ends.

  In S110, the session management unit 26 notifies the terminal connection state monitoring unit 21 of the start of the session together with the ID of the terminal 50. Conversely, the terminal connection state monitoring unit 21 may periodically inquire the session management unit 26. Next, in S112, the terminal connection state monitoring unit 21 notifies the clock correction unit 22 of the start of the session.

  The clock correction unit 22 calculates and manages the time of the system clock 25 when it goes offline for each terminal 50 and the accumulated value of the time when it goes offline for each terminal 50, and is notified in S114. Initialize the entry of the terminal 50. Subsequently, in S116, the terminal connection state monitoring unit 21 starts monitoring the terminal connection state. At the start of the session, the offline time is empty and the accumulated offline time is set to zero.

Terminal connection state monitoring process (corresponding to operation phases (3) and (4)): FIG. 8 is a flowchart illustrating the processing contents of the terminal connection state monitoring process.
In S200, the session management unit 26 periodically checks the connection state of the terminal 50. That is, the session information managed by the session management unit 26 itself may be confirmed, the presence / absence of a packet from the terminal 50, or a response by ping may be confirmed. The session management unit 26 notifies the terminal connection state monitoring unit 21 of the result together with the terminal ID, and proceeds to S202.

  In S202, the terminal connection state monitoring unit 21 confirms whether or not the terminal 50 has changed from the previous connection state. That is, it is determined whether online has changed to offline or offline has changed to online. If there is a change, the process proceeds to S204, and the terminal connection state monitoring unit 21 notifies the clock correction unit 22 of the change. If there is no change, the process returns to S200.

  Subsequent to S204, in S206, the terminal connection state monitoring unit 21 determines whether or not the change in the connection state of the terminal 50 is a change from online to offline.

  If the determination result in S206 is YES, that is, if the change is from online to offline, the process proceeds to S208, and the terminal connection state monitoring unit 21 records the time of the system clock in the offline time of the terminal state management table, and S200. Return to.

  When the determination result in S206 is NO, that is, when the connection state changes from offline to online, the process proceeds to S210, and the terminal connection state monitoring unit 21 acquires the current time from the system clock 25. In step S212, the terminal connection state monitoring unit 21 adds the difference between the current time of the system clock 25 and the offline time of the terminal state management table to the accumulated offline time. In step S214, the terminal connection state monitoring unit 21 empties the offline time. Thereafter, the process returns to S200.

  Event stream playback process (corresponding to operation phases (2) and (4)): FIG. 9 is a flowchart illustrating the process contents of the event stream playback process. First, the terminal 50 collects data from the sensor and transmits it to the event receiving unit 27 as an event. The terminal 50 may transmit events one by one, or may transmit a plurality of events collectively. If the terminal is online, it can be sent one at a time when the events are collected. However, if the terminal is immediately after moving from offline to online, it is better to send the collected events while offline to delay the event. This is because it can be made smaller.

  In S300, the event reception unit 27 analyzes the event transmitted from the terminal 50, converts it into an internal format, and passes it to the event stream reproduction unit 23. Then, in S302, the event stream playback unit 23 decomposes the passed events one by one as necessary, and the stream engine 24 at the time when the event arrives for each event. To enter. The stream engine 24 requests the clock correction unit 22 for the apparent time of the terminal 50.

  In step S304, the clock correction unit 22 acquires the accumulated offline time using the terminal ID as a key. Subsequently, in S306, the clock correction unit 22 acquires the offline time of the terminal 50 from the terminal connection state management table. In step S308, the clock correction unit 22 determines whether the offline time of the terminal 50 exists.

  If the determination result in S308 is YES, that is, if the time exists, the process proceeds to S312 and the terminal 50 is currently in an offline state, so the clock correction unit 22 sets the correction time obtained by subtracting the accumulated offline time from the offline time to the stream engine 24. Return to Thereafter, the process proceeds to S314.

  When the determination result in S308 is NO, that is, when the offline time does not exist, the process proceeds to S310, where the clock correction unit 22 acquires the current time from the system clock 25 and uses the correction time obtained by subtracting the accumulated offline time as the stream engine. Return to 24. Thereafter, the process proceeds to S314.

  In S314, the clock correction unit 22 determines whether the apparent time of the terminal 50 acquired as described above is newer than the event generation time. If the determination result in S314 is NO, the process proceeds to S316, and the clock correction unit 22 waits for a certain period of time because the time at which the event should be processed is not reached, returns to S304, and repeats the same process. In addition, the delay time of event arrival may be measured regularly, and the time may be taken into account. Subsequent processing depends on the query given to the stream engine 24, but processing dependent on the arrival time of the event such as timer processing or time window processing refers to the time. The process at that time is the same as the time reference process described above.

  If the determination result in S314 is YES, the process proceeds to S318, and the clock correction unit 22 passes the event to the stream engine 24, and then proceeds to S320 to end the repetition process.

Thereafter, processing that depends on the query executed by the stream engine 24 is performed. In S322, the stream engine 24 processes the query. In the middle of the process, in S324, the stream engine 24 acquires time as necessary (executes the time acquisition process described above). Thereafter, in S326, the stream engine 24 outputs an event.
In the above, iterative processing need not be performed synchronously, but can be performed sequentially.

  Session termination (corresponding to the operation phase (5)): The session management unit 26 performs session termination processing. At this point, since the terminal is online, there is no need to change the entry in the terminal connection state management table of the clock correction unit 22, so nothing is done to the terminal connection state monitoring unit 21. The reason why the entry in the terminal connection state management table is not deleted is that when the query processed by the stream engine 24 includes timer processing or time window processing, clock reference can be made even if the session ends.

  In the above operation, once the terminal goes offline, the apparent time is delayed from the actual time by the time when the terminal has been offline. Then, every time the terminal 50 repeats offline / online, the time when the stream engine 24 processes the event is delayed, and the real-time property is deteriorated. In order to prevent this, it is possible to make the apparent time advance faster and process the event faster than usual. In that case, when the past event processing ends and catches up with the current time, the way the apparent time advances is restored.

<Second Embodiment>
FIG. 10 is a configuration diagram of an event processing system according to the second embodiment. As shown in FIG. 10, the event processing system 30 includes a terminal connection state monitoring unit 31, a clock correction unit 32, an event stream reproduction unit 33, a stream engine 34, a system clock 35, a session management unit 36, An event receiving unit 37, and a VM management unit 38 and a clock acquisition unit 39.

  In the first embodiment, in order for the event stream playback unit 23 and the stream engine 24 to use the apparent time of the terminal 50, the ID of the terminal 50 is necessary, and a dedicated Application Programming Interface (API) is used. Is assumed to be used. Therefore, in the present embodiment, in order to be applicable to a general stream engine, a virtual machine (VM, virtual machine) having a function of referring to an apparent time as a clock is prepared for each terminal 50 ( In other words, n VM1, VM2,..., VMn are prepared), and the event stream playback unit 33 and the stream engine 34 may be executed by the dedicated VM.

The present embodiment is different from the configuration of the first embodiment in that a VM management unit 38 and a clock acquisition unit 39 are provided.
The VM management unit 36 manages a VM that processes an event for each terminal 50.

  The clock acquisition unit 39 remembers the ID of the terminal 50 processed by the VM, and acquires the apparent time from the clock correction unit 32 by using the ID.

  In the session start operation, a process in which the session management unit 36 notifies the VM management unit 38 that the session of the predetermined terminal 50 is started is added to the above-described operation. The VM management unit 38 checks whether a VM with the designated terminal ID exists, and if not, creates a VM including the event stream playback unit 33, the stream engine 34, and the clock acquisition unit 39, Initialization such as setting a terminal ID or registering a query in the stream engine is performed.

  When the event receiving unit 37 receives an event, the event stream playback processing operation inquires the VM management unit 38 about the VM for processing the event, and distributes the event to the event stream playback unit 33 of the VM. The subsequent processing is as described above, and initialization such as registering a query in the event stream reproduction unit 33 and the stream engine 34 is performed.

  When the event reception unit 37 receives an event, the event stream playback process is inquired of the VM management unit 38 about the VM for processing the event, and the event stream playback unit 33 and the stream engine 34 of the VM apparently appear. Get the time. By doing so, it is possible to process an off-line event without changing the existing stream engine product.

  The operation of the event processing system according to the present embodiment and the example of the computer commonly applied to cause the computer to perform the event processing are the same as those shown in FIG.

  The CPU 71 uses the memory 72 to execute the event processing program, whereby the terminal connection state monitoring unit 31, the clock correction unit 32, the event stream reproduction unit 33, the stream engine 34, the system clock 35, and the session management unit in FIG. 36, the event receiving unit 37, the VM managing unit 38, and the clock acquiring unit 39.

  As described above, according to the present embodiment, when an event is collected from a wireless terminal and stream processing is performed, the clock referred to by the stream engine is controlled so that the event is recognized as if it has just arrived. Even if the arrival of an event is greatly delayed, it can be handled correctly.

  Although the embodiment of the present invention has been described as described above, the present invention is not limited to the above-described embodiment, and various other modifications are possible.

In addition, the following additional remarks are disclosed regarding the embodiment described above.
(Appendix 1)
An event processing method executed by a computer,
Monitor the connection status of the terminal that sends the data collected by the sensor to the event processing system as event data,
Calculate the cumulative value of the time when the terminal cannot communicate,
When performing stream processing, calculate the correction time by subtracting the cumulative value from the time of the system clock,
Streaming and outputting event data transmitted from the terminal based on the correction time,
An event processing method characterized by the above.
(Appendix 2)
The event processing method according to appendix 1, wherein the stream processing is performed by a different virtual machine for each terminal.
(Appendix 3)
The event processing method according to appendix 1, wherein the event processing is performed by setting an interval of events transmitted during a time during which communication is impossible to be shorter than actual.
(Appendix 4)
A terminal connection state monitoring unit for monitoring a connection state of a terminal that transmits data collected by the sensor to the event processing system as event data;
A clock correction unit that calculates a cumulative value of the communication impossible time of the terminal, and calculates a correction time obtained by subtracting the cumulative value from a system clock time when performing stream processing;
An event stream playback unit for inputting event data transmitted from the terminal to a stream engine;
A stream engine that processes and outputs the event data based on the correction time;
A system clock that provides the actual time, and
An event processing system comprising:
(Appendix 5)
The event processing system according to appendix 4, wherein the stream processing is performed by a different virtual machine for each terminal.
(Appendix 6)
The event processing system according to appendix 4, wherein the event processing is performed by setting an interval of events transmitted during a time during which communication is impossible to be shorter than actual.
(Appendix 7)
Monitor the connection status of the terminal that sends the data collected by the sensor to the event processing system as event data,
Calculate the cumulative value of the time when the terminal cannot communicate,
When performing stream processing, calculate the correction time by subtracting the cumulative value from the time of the system clock,
Streaming and outputting event data transmitted from the terminal based on the correction time,
An event processing program that causes a computer to execute processing.
(Appendix 8)
The event processing program according to appendix 7, wherein a plurality of the terminals are provided, and the stream processing is performed by a different virtual machine for each terminal.
(Appendix 9)
9. The event processing program according to appendix 8, wherein the event processing is performed by setting an interval of events transmitted during a time during which communication is impossible to be shorter than actual.

DESCRIPTION OF SYMBOLS 10 Event processing system 11 Terminal connection state monitoring part 12 Clock correction part 13 Event stream reproduction | regeneration part 14 Stream engine 15 System clock 16 Session management part 17 Event reception part 18 VM management part 19 Clock acquisition part

Claims (5)

An event processing method executed by a computer,
Monitor the connection status of the terminal that sends the data collected by the sensor to the event processing system as event data,
Calculate the cumulative value of the time when the terminal cannot communicate,
When performing stream processing, calculate the correction time by subtracting the cumulative value from the time of the system clock,
Streaming and outputting event data transmitted from the terminal based on the correction time,
An event processing method characterized by the above.   The event processing method according to claim 1, wherein a plurality of the terminals are provided, and the stream processing is performed by a different virtual machine for each terminal. 2. The event processing method according to claim 1, wherein the stream processing is performed by shortening an interval of events at which the sensor collects the event data during a time during which communication is impossible. A terminal connection state monitoring unit for monitoring a connection state of a terminal that transmits data collected by the sensor to the event processing system as event data;
A clock correction unit that calculates a correction value obtained by subtracting the cumulative offline time from a system clock time when calculating a cumulative value of the terminal incapable communication and performing stream processing;
An event stream playback unit for inputting event data transmitted from the terminal to a stream engine;
A stream engine that processes and outputs the event data based on the correction time;
A system clock that provides the actual time, and
An event processing system comprising: Monitor the connection status of the terminal that sends the data collected by the sensor to the event processing system as event data,
Calculate the cumulative value of the time when the terminal cannot communicate,
When performing stream processing, calculate the correction time by subtracting the cumulative value from the time of the system clock,
Streaming and outputting event data transmitted from the terminal based on the correction time,
An event processing program that causes a computer to execute processing.