JP2014033371A - Information sharing system, terminal, switching method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance stability in information sharing between terminals.SOLUTION: An information sharing system includes a first terminal for holding the original of data, and one or more second terminals synchronized with the first terminal for that data. The first terminal includes a detection unit 130 for detecting that the first terminal may be impossible to maintain master operation, and a first switching unit for switching the operation of the first terminal from master operation to slave operation, when the detection unit 130 detected that the first terminal may be impossible to maintain master operation. The second terminal includes a second switching unit for switching the operation of the second terminal from slave operation to master operation, when the detection unit 130 detected that the first terminal may be impossible to maintain master operation.

Description

  The present invention relates to an information sharing system, a terminal device, a switching method, and a program.

  Conventionally, a database or the like has a redundant configuration so that there is no problem in service continuity even when a failure occurs. A case where private information (for example, schedule, phone book, photo, video, etc.) is shared between terminal devices within a network connected to a limited number of terminal devices (mobile information devices) such as a home wireless LAN environment. There is. Information sharing in such a case can be realized by synchronizing each terminal device with a file stored in the cloud, but some people have resistance to depositing private information in the cloud. Here, “synchronization” means to align the contents at a certain cycle or timing.

  On the other hand, a dedicated server can be provided in the home, and sharing can be realized while keeping private information in the home. However, installing such a dedicated server in the home is a burden on the user. Therefore, it is more desirable that it can be realized only by the terminal device. However, assigning a server role to a specific terminal is not suitable in a home where a terminal device enters and exits.

  On the other hand, in Patent Document 1, in a method of managing shared information by enabling communication between a plurality of terminal devices via a communication network, all data of the shared information is transmitted to any one of the plurality of terminal devices. A replica of shared information in which at least a part of the original of the shared information data is duplicated is stored in at least one of the other terminal devices, and one of the shared information replicas is mastered. When switching to, it is described that the original master of shared information is switched to a replica, so that management of shared information can be continued even if a failure occurs in one of a plurality of terminal devices.

JP 2004-5199 A

Terminal devices (mobile information devices) often move together with people, and they often leave the network other than when a failure occurs.
For this reason, when using the system of Patent Document 1, since switching between the original data and the replica (replication of the original data) is performed more frequently, the terminal device that holds the original data for a certain time each time. May be absent. Therefore, while there is no terminal that holds the original data, a synchronization service that synchronizes the original data and the replica cannot be provided, and the stability of information sharing between the terminal devices decreases. The inventor has discovered that

  Accordingly, the present invention has been made in view of the above problems, and it is an object to provide an information sharing system, a terminal device, a switching method, and a program that can improve the stability of information sharing between terminal devices. And

  (1) The present invention has been made in view of the above circumstances. One aspect of the present invention is a first terminal device that holds an original data, and one device that synchronizes the data with the first terminal device. Or an information sharing system comprising a larger number of second terminal devices, wherein the first terminal device may not be able to maintain the master operation of the first terminal device. When the detection unit detects that there is a possibility that the first terminal device cannot maintain the master operation, the operation of the first terminal device is changed from the master operation to the slave operation. A first switching unit that switches to the second terminal device, wherein the second terminal device detects that the first terminal device may not be able to maintain the master operation, Of the second terminal device Create a is an information sharing system comprising a second switching unit for switching the master operation from the slave operation.

  (2) In the information sharing system described above, according to one aspect of the present invention, the first terminal device can detect that the detection unit may be disconnected from the network. Yes, the first switching unit switches the operation of the first terminal device from a master operation to a slave operation when the detection unit detects that the first terminal device may be disconnected from the network. The second switching unit switches the operation of the second terminal device from the slave operation to the master operation when the detection unit detects that the first terminal device may be disconnected from the network.

  (3) In the information sharing system described above, according to one aspect of the present invention, when the second switching unit starts a process in which the first terminal device transfers master authority, If the terminal device is in a state where it can become a master, it notifies the first terminal device that it is requested to transfer the master authority, and the master device from the first terminal device When the authority is transferred, the operation of the second terminal device is switched from the slave operation to the master operation.

  (4) In the information sharing system described above, according to one aspect of the present invention, the detection unit is configured to disconnect from an external power source, decrease in remaining battery power, decrease in remaining operable time, movement of own terminal, wireless state At least one of the deterioration of the user and the user's operation is detected.

  (5) One aspect of the present invention is an information sharing system including a terminal device that holds an original data and one or more slave terminal devices that synchronize the data with the terminal device. Based on the detection result detected by the detection unit and the detection unit that detects that there is a possibility that the terminal device used may not be able to maintain the master terminal device having a master authority. And a switching unit that switches the operation of the terminal device from a master operation to a slave operation.

  (6) One aspect of the present invention is an information sharing system including a master terminal device that holds an original data and one or more terminal devices that synchronize the master terminal device and the data When the master terminal device detects that the master terminal device may not be able to maintain the master operation, the operation of the own terminal device is changed from the slave operation to the master operation. It is a terminal device provided with the switching part to switch.

  (7) According to one aspect of the present invention, a first terminal device that holds an original data, and one or more second terminal devices that synchronize the data with the first terminal device The first terminal device used in the information sharing system comprising: a step of detecting that the detection unit may not be able to maintain a state in which the terminal device is a master. And a step of switching the operation of the terminal device from the master operation to the slave operation based on the detection result detected by the detection unit.

  (8) According to one aspect of the present invention, a first terminal device that retains an original data, one or more second terminal devices that synchronize the data with the first terminal device, Switching method executed by the second terminal device used in the information sharing system comprising: the first terminal device may not be able to maintain the master operation by the first terminal device Is detected, the switching unit has a step of switching the operation of the terminal device from the slave operation to the master operation.

  (9) According to one aspect of the present invention, a first terminal device that holds an original data and one or more second terminal devices that synchronize the data with the first terminal device A detection step for detecting that the first terminal device used in the information sharing system comprising the information processing system may not be able to maintain a state in which the terminal device is a master, and a detection detected by the detection step This is a program for executing the switching step of switching the operation of the terminal device from the master operation to the slave operation based on the result.

  (10) According to one aspect of the present invention, a first terminal device that holds an original data, and one or more second terminal devices that synchronize the data with the first terminal device When it is detected by the first terminal device that the first terminal device may not be able to maintain the master operation in the second terminal device used in the information sharing system comprising: This is a program for executing a switching step for switching the operation of the terminal device from the slave operation to the master operation.

  ADVANTAGE OF THE INVENTION According to this invention, the stability of the information sharing between terminal devices can be improved.

It is a schematic block diagram which shows the structure of the information sharing system in 1st Embodiment. It is a figure which shows an example of the master authority delegation process of the information sharing system in 1st Embodiment. It is a schematic block diagram which shows the structure of the terminal device in 1st Embodiment. It is a figure which shows an example of the flow of a data synchronous process between a master terminal device and a slave terminal device. It is a flowchart which shows an example of the flow of a process until it starts the transfer of the master of the terminal device in 1st Embodiment. It is a sequence diagram which shows an example of the flow of a process of the information sharing system in 1st Embodiment. It is a schematic block diagram which shows the structure of the information sharing system in 2nd Embodiment. It is a schematic block diagram which shows the structure of the terminal device in 2nd Embodiment. It is a schematic block diagram which shows the structure of the information sharing system in 3rd Embodiment. In 3rd Embodiment, it is a schematic block diagram which shows the structure of the terminal device in the case of operate | moving as a master terminal device. In 3rd Embodiment, it is a schematic block diagram which shows the structure of the terminal device in the case of operate | moving as a slave terminal device. It is a schematic block diagram which shows the structure of the information sharing system in 4th Embodiment. It is a schematic block diagram which shows the structure of the terminal device in 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each embodiment, a master terminal device (hereinafter also referred to as “first terminal device”) is a terminal device (hereinafter referred to as “terminal” or “mobile” that holds an original data (hereinafter also referred to as master). Information equipment). In this embodiment, as an example, the master terminal device is responsible for notifying update data to other terminal devices. A slave terminal device (hereinafter sometimes referred to as a “second terminal device”) is a terminal device that synchronizes data with a master terminal device. Here, to synchronize means to make the contents the same. The original data is the only representative data selected to guarantee consistency in a state where the same data copy exists in a plurality of terminals. Data consistency is determined based on this original.

  In the present embodiment, as an example, the slave terminal device notifies the master terminal device of update data at the time of data update, and updates the data of its own terminal device according to the update completion notification from the master. The operation of the slave terminal device is not limited to this, and the update notification to the master terminal device and the update of the data of the own terminal may be performed simultaneously. The slave terminal device includes a device that receives a replica that is a replica of the master and reflects the replica in the storage device.

<First Embodiment>
FIG. 1 is a schematic block diagram illustrating a configuration of an information sharing system 1 according to the first embodiment. The information sharing system 1 includes a terminal device 100-1 (hereinafter also referred to as “terminal A”), a terminal device 100-2 (hereinafter also referred to as “terminal B”), and a terminal device 100-3 (hereinafter referred to as “terminal”). C ”) and an access point 200. As an example, as an initial state, the terminal device 100-1 is a master terminal device, and the terminal device 100-2 and the terminal device 100-3 are slave terminal devices. The terminal devices 100-1 to 100-3 are also collectively referred to as the terminal device 100. The terminal device 100 is a mobile phone, for example. In this embodiment, as an example, it is assumed that both the terminal device 100-2 and the terminal device 100-3 can become master terminal devices when the master authority is transferred from the terminal device 100-1. Note that either the terminal device 100-2 or the terminal device 100-3 may be a terminal that can only be a slave terminal device.

Each terminal device 100 communicates with the access point 200. The access point 200 transfers data received from each terminal device 100 to another terminal device 100.
The information sharing system 1 in the present embodiment includes the three terminal devices 100. However, the number of the terminal devices 100 is not limited to this, and may be two, or four or more. May be. That is, the information sharing system 1 may include a master terminal device that holds the original data and one or more slave terminal devices that synchronize the master terminal device with the data.

Here, a master terminal device which is a terminal device having master authority performs a master operation. The master operation includes, for example, holding an original data, receiving update data from the slave terminal device, and notifying the slave terminal device of an update of the original data. In the case of notifying the slave terminal device of the update of the original data, the case where the own terminal directly notifies the slave terminal device or the case where it is indirectly notified via another device is included.
On the other hand, a slave terminal device, which is a terminal device without master authority, performs a slave operation. The slave operation includes, for example, notifying update data in the own terminal to the master device, receiving the original data from the master terminal device, and updating the data in the own terminal with the received original data.

  FIG. 2 is a diagram illustrating an example of a master authority delegation process of the information sharing system 1 according to the first embodiment. At time T1, terminal A is in the master state. Here, the master state is a state having master authority, and means that the own terminal is a master terminal device. When it is detected that the terminal A is likely to be removed from the network, the terminal A transfers the master authority to the terminal C at time T2. At time T3, even if terminal A is disconnected from the network, since terminal C is in the master state, data can be synchronized between terminal B and terminal C. As described above, even if the terminal A in the master state is disconnected from the network, the master authority is transferred to the terminal C before the terminal A is disconnected from the network, so that the data synchronization service is not interrupted.

  FIG. 3 is a schematic block diagram illustrating a configuration of the terminal device 100 according to the first embodiment. The terminal device 100 includes an input unit 110, a display unit 120, a detection unit 130, a communication unit 140, a storage unit 150, and a control unit 160.

The input unit 110 receives input from a user who operates the terminal. Here, the input unit 110 includes an input button 111 and a touch panel 112 as an example. When the input button 111 is pressed by the user, the input button 111 outputs a signal indicating that the input button 111 has been pressed to the control unit 160. The touch panel 112 receives a user's touch operation and outputs touch operation information indicating the received touch operation to the control unit 160.
The display unit 120 displays a screen under the control of the control unit 160.

  When the own terminal is in the master state, the detecting unit 130 detects, for example, that the own terminal is in a state where there is a possibility that the own terminal is disconnected from the network. Here, “disengaging from the network” means going out of the communication area with the access point 200 as an example. As an example of detection, the detection unit 130 detects that the master terminal has been disconnected from the external power source (for example, disconnected from the AC power source), that is, has been switched to driving by a battery (not shown) included in the own device. .

  In addition, although the detection part 130 in this embodiment detected having disconnected from the external power supply, it is not restricted to this. The detecting unit 130 may detect that the remaining battery level is less than a predetermined threshold remaining amount, or detect that the remaining operable time is shorter than a predetermined threshold operating time. May be.

In addition, the detection unit 130 may include, for example, an acceleration sensor, and may detect that the own terminal has changed from a stationary state to a moving state based on the acceleration detected by the acceleration sensor.
Further, the detection unit 130 may detect that the wireless state (for example, RSSI (Received Signal Strength Indicator), SNR (Signal to Noise ratio), link speed, etc.) has deteriorated, for example. Good. Specifically, for example, when at least one of RSSI, SNR, or link speed becomes smaller than a predetermined threshold value, it may be detected that the radio state has deteriorated.

Moreover, the detection part 130 may detect that the input button 111 of the own terminal was pressed or the touch panel 112 of the own terminal was operated, for example.
Note that the detection unit 130 may detect any one or more of the above, for example. That is, the detection unit 130 detects at least one of disconnection from the external power source, a decrease in the remaining battery power, a decrease in the remaining operable time, a movement of the own terminal, a deterioration in the wireless state, and a user operation. Also good.

  When the detection unit 130 detects that the own terminal is likely to be disconnected from the network, the control unit 160 can transfer the master authority to another terminal device. It is possible to shorten the time during which the service that synchronizes between them cannot be provided.

  In the present embodiment, the detection unit 130 performs detection every time when the terminal enters a state where there is a possibility that the terminal is disconnected from the network. However, the present invention is not limited to this. It is also possible to detect whether or not the terminal has entered a state where there is a possibility of disconnecting from the network. In the present embodiment, the detection unit 130 detects that the terminal itself is likely to be disconnected from the network. However, the detection unit 130 is not limited to this, and the detection unit 130 determines whether the load is a predetermined threshold. May be detected, or a temperature sensor may be provided to detect that the temperature of the terminal itself is higher than a predetermined temperature. As a result, when the detection unit 130 detects that the load is greater than a predetermined threshold, the control unit 160 can transfer the master authority to another terminal device. It is possible to shorten the time during which the service that synchronizes between the services cannot be provided. In addition, when the detection unit 130 detects that the temperature of its own terminal is higher than a predetermined temperature, the control unit 160 can transfer the master authority to another terminal device, so that the master and replica It is possible to shorten the time during which the service that synchronizes with the server cannot be provided.

  As described above, the master terminal device only needs to be able to transfer the master authority to another terminal device before the master operation cannot be maintained. For this reason, the detection unit 130 may detect that the terminal itself may not be able to maintain the master operation. Here, when the master operation cannot be maintained, for example, when the original data cannot be retained, or when the update data cannot be received from the slave terminal device, the master terminal is notified of the update of the original data. This is the case when it becomes impossible. When it becomes impossible to notify the slave terminal device of the update of the original, the case where the own terminal cannot directly notify the slave terminal device or the case where it cannot be indirectly notified through another device is included. Shall be.

The communication unit 140 receives instructions from the synchronization control switching unit 162, the master synchronization control unit 163, and the slave synchronization control unit 164, and communicates with other terminal devices via the access point 200. For example, the communication unit 140 communicates with other terminal devices via a wireless LAN. The communication unit 140 may communicate with other terminals via Bluetooth (registered trademark), a communication line of a mobile phone, or a wired LAN.
The storage unit 150 stores data to be synchronized using, for example, a built file system or database. The storage unit 150 is, for example, a flash memory or an HDD (Hard Disk Drive: hard disk).

  The control unit 160 controls each unit. Here, the control unit 160 includes the above-described synchronization control switching unit (hereinafter also referred to as “switching unit”) 162, a master synchronization control unit 163, and a slave synchronization control unit 164.

  The synchronization control switching unit 162 switches between the master synchronization control unit 163 and the slave synchronization control unit 164 to operate. When the own terminal is the master terminal device, the synchronization control switching unit 162 starts the master authority transfer process when the detecting unit 130 detects that the own terminal may be removed from the network. Then, when the master authority transfer is successful, the synchronization control switching unit 162 switches the operation of the own terminal from the master operation to the slave operation. At that time, the synchronization control switching unit 162 stops the master synchronization control unit 163 and operates the slave synchronization control unit 164.

  Next, details of the master authority transfer process will be described. For example, in order to search for a terminal device that can become a master terminal device, the synchronization control switching unit 162 inquires of another terminal whether or not it can become a master terminal device via the communication unit 140. For example, the synchronization control switching unit 162 receives a candidate for the master terminal device from another terminal via the communication unit 140. At that time, for example, the synchronization control switching unit 162 is informed of information such as the power state, remaining operation prediction time, radio state, physical state (how long, not physically moving) of the terminal that has run as a master terminal device. Is received from the candidate terminal device.

  The synchronization control switching unit 162 selects an optimal terminal device as the master terminal device from among the terminal devices that have run as master terminal devices. At that time, when there are a plurality of master terminal device candidates and the master terminal device is selected, for example, the synchronization control switching unit 162 is connected to an AC power source among slave terminal devices running as master terminal devices. Select the master terminal device with higher priority. For example, when only the terminal device C is connected to the AC power source among the terminal devices B and C, the end device A selects the terminal device C as a master terminal device.

  Note that the synchronization control switching unit 162 may select a terminal device with a large remaining battery level as a master terminal device with higher priority. For example, the synchronization control switching unit 162 may select a terminal device with the largest remaining battery level as the master terminal device. Further, the synchronization control switching unit 162 may preferentially select a terminal device having a long remaining operation prediction time as a master terminal device. For example, the synchronization control switching unit 162 may select the terminal having the longest remaining estimated operation time as the master terminal device. In addition, the synchronization control switching unit 162 may prioritize and select a terminal device that is not physically operated for a long time as a master terminal device. For example, the synchronization control switching unit 162 may select a terminal device that is not physically operated for a longer time than a predetermined time as the master terminal device, or is not physically operated for the longest time. The terminal device may be selected as a master terminal device. In addition, the synchronization control switching unit 162 may select a terminal device having a better radio condition (for example, RSSI (received signal strength) or link speed) as a master terminal device with higher priority than a predetermined standard. Good. For example, the synchronization control switching unit 162 may select the terminal device with the largest RSSI as the master terminal device, or may select the terminal with the fastest link speed as the master terminal device. In addition, the synchronization control switching unit 162 may, for example, perform scoring by weighting each of the above items, and select the terminal with the highest score as a new master terminal device.

  Then, the synchronization control switching unit 162 notifies the selected terminal device that the master authority is transferred via the communication unit 140. Then, the synchronization control switching unit 162 receives from the selected terminal device via the communication unit 140 that the master operation has been switched (master preparation complete). In that case, the synchronization control switching unit 162 switches the operation of the own terminal from the master operation to the slave operation, assuming that the master authority transfer is successful.

  When the own terminal is a slave terminal device, the synchronization control switching unit 162 determines whether the master terminal device is ready when it detects that another terminal device has started the master authority transfer process. . When the synchronization control switching unit 162 determines that the master terminal device is ready to be used, the synchronization control switching unit 162 requests transfer of master authority via the communication unit 140 (for example, the master terminal device candidacy). To the master terminal device. At that time, the synchronization control switching unit 162, via the communication unit 140, such as the power state of the terminal device, the estimated remaining operation time, the wireless state, the physical state (how long, not physically moving), etc. Information may be transmitted to the master device together with the fact that the candidate is running. When the master authority is transferred from the master terminal device, the synchronization control switching unit 162 switches the operation of the own terminal from the slave operation to the master operation. At that time, the synchronization control switching unit 162 stops the slave synchronization control unit 164 and operates the master synchronization control unit 163.

  Here, an example of specific processing when determining whether or not the master terminal device is ready will be described. For example, the synchronization control switching unit 162 determines that the master terminal device is ready when the data synchronization with the master terminal device is synchronized. Note that, when the battery is driven, the synchronization control switching unit 162 may not run as a master terminal device. Further, the synchronization control switching unit 162 determines that the master terminal device is ready when the data is synchronized with the master terminal device and at least one of the following conditions is satisfied. May be. The following conditions are, for example, when the own terminal device is connected to an AC power source, when the remaining battery level is greater than a predetermined threshold, and the own terminal has not physically moved for a predetermined time or more. Or radio conditions (for example, RSSI, link speed, etc.) are better than predetermined conditions. The synchronization control switching unit 162 may perform scoring by weighting each of the above conditions, and may determine that the master terminal device is ready when the sum of the scores is greater than a predetermined threshold.

  As described above, when the terminal device 100 is a master terminal device, the synchronization control switching unit 162 operates the own terminal (master terminal device) when detecting that the master terminal device may not be able to maintain the master operation. Functions as a first switching unit that switches from master operation to slave operation. On the other hand, when the terminal device 100 is a slave terminal device, the detection unit 130 of the master terminal device detects that the master terminal device may not be able to maintain the master operation, and whether or not the master terminal device can transfer master authority. The synchronization control switching unit 162 functions as a second switching unit that switches the operation of the own terminal device (slave terminal device) from the slave operation to the master operation.

  When the terminal device 100 is a slave terminal device, the synchronization control switching unit 162 determines whether or not the own terminal device can become a master when the master terminal device starts a process of delegating master authority. It functions as a second switching unit. Then, the synchronization control switching unit 162 notifies the master terminal device that it is a candidate for the master terminal device when the terminal device is in a master state, and when the master authority is transferred from the master terminal device, It functions as a second switching unit that switches the operation of its own terminal device (slave terminal device) from the slave operation to the master operation.

Note that master authority transfer may be attempted periodically regardless of the output of the detection unit. If the status of the slave terminal device has changed from the current master terminal device to a state more suitable for the master terminal device even if the master time state has not changed, the master terminal device becomes the master terminal device more suitable for the master terminal device. Authority can be transferred. As a result, the stability of the synchronization service between the master and the replica can be improved.
In addition, when the slave terminal device changes its state (for example, when connected to an AC power source), the slave terminal device notifies the master terminal device of the change mode (for example, connected to the AC power source). Also good. In that case, the master terminal device determines whether or not the state of the slave terminal device is better than the current state of the master terminal device, and if so, the master terminal device transfers the master authority to the slave terminal device. You may make it do. As a result, the master terminal device can transfer the master authority to a terminal more suitable for the master terminal device, so that the stability of the synchronization service between the master and the replica can be improved.

  The master synchronization control unit 163 is a synchronization control unit used when the own terminal is in the master state. For example, the master synchronization control unit 163 updates the master stored in the own terminal when the data of the own terminal is updated or when update data of another terminal is received. Then, the master synchronization control unit 163 notifies the updated data to each slave terminal device, for example.

  The slave synchronization control unit 164 is a synchronization control unit used when the own terminal is in a slave state. For example, the slave synchronization control unit 164 updates the data in the data area reserved for local storage when the data of the terminal itself is updated. Then, the slave synchronization control unit 164 notifies the master terminal device of the update data. When receiving update data from the master terminal device, the slave synchronization control unit 164 updates the replica with the received update data. Here, the replica is a replica of the master. When the slave terminal device transfers the master authority and becomes the master terminal device, this replica becomes the master.

  Note that it is not necessary for all terminal devices included in the information sharing system 1 to have all the above-described configurations, and a terminal device that can only be a slave terminal device can participate in the information sharing system 1.

Next, a flow of data synchronization processing between the master terminal device and the slave terminal device will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of a flow of data synchronization processing between the master terminal device and the slave terminal device. In the figure, terminal A is a master terminal device, and terminal B is a slave terminal device.
(Time T101) Synchronization is established between the master M1 of the terminal A and the replica S1 of the terminal B. Here, the contents of the data of the master M1 are expressed as “■■■■”. Further, the contents of the data of the replica S1 are represented as “■■■■”.

(Time T102) Terminal B leaves the network.
(Time T103) A change is made to the master of terminal A. Here, in the master M2, “▲▲▲” is the changed data.
(Time T104) The replica of the terminal B is changed. In the replica S2 after the change is made, a branch (local branch) is generated from the end of the synchronized data “■■■■”, and the change data “□□” is added to the local branch. ing. Thus, since the terminal B cannot synchronize with the master, for example, the change made is distinguished and recorded as a local change.

(Time T105) Terminal B returns to the network and enters a slave state.
(Time T106) Terminal B obtains master update data “▲▲▲” from terminal A. Thereby, the replica data S3 includes “■■■■ ▲▲▲” and “□□” existing in the local branch branched from the end of “■■■■”.
(Time T107) The terminal B performs merging so as to be updated from the latest master. As a result of merging, in the replica S4, “□□” existing in the local branch branched from the end of “■■■■” exists in the local branch branched from the end of “■■■■ ▲▲▲”. ◇ ”has been changed. This is because the data change “□□” from “■■■■” has become the data change “◇◇” from “■■■■ ▲▲▲”.

(Time T108) Terminal B transmits update data “◇◇” to terminal A.
(Time T109) The terminal A updates the master with the update data “◇◇” received from the terminal B. As a result, the contents of the data of the master M3 are “■■■■ ▲▲▲ ◇◇”.
(Time T110) The terminal B acquires the master update “◇◇” from the terminal A. As a result, the data in the replica S5 becomes “■■■■ ▲▲▲ ◇◇” which is the same as that of the master M3. This completes the synchronization.

FIG. 5 is a flowchart illustrating an example of a processing flow until the master transfer of the terminal device 100-1 according to the first embodiment is started.
(Step S101) First, the control unit 160 of the terminal device 100-1 determines whether or not the own terminal is in a master state. If the control unit 160 determines that the terminal is not in the master state (NO), the control unit 160 waits as it is. When the control unit 160 determines that the terminal is in the master state (YES), the control unit 160 proceeds to the process of step S102.
(Step S102) Next, the detection unit 130 determines whether or not it is detected that it is likely to be disconnected from the network. When the detection unit 130 has not detected that it is likely to be disconnected from the network (NO), the control unit 160 returns to the process of step S101. When it is detected that the detection unit 130 is likely to be disconnected from the network (YES), the control unit 160 proceeds to the process of step S103.
(Step S103) Next, the synchronization control switching unit 162 starts a master authority transfer process. Above, the process of this flowchart is complete | finished.

FIG. 6 is a sequence diagram illustrating an example of a processing flow of the information sharing system 1 according to the first embodiment. It is assumed that terminal A is a master terminal device. This figure shows a case where terminal A, which is a master terminal device, grasps all slave terminal devices.
(Time T201) The terminal A detects that the terminal may be disconnected from the network.

(Time T202) The terminal A inquires of the terminal B whether or not it can become the master terminal device in order to search for a terminal that can become the master terminal device.
(Time T203) Terminal B notifies terminal A that it is a candidate for a master terminal device.
(Time T204) In order to search for a terminal that can become a master terminal device, the terminal A inquires of the terminal C whether or not it can become a master terminal device.
(Time T205) The terminal C notifies the terminal C that it is a candidate for the master terminal device.

(Time T206) The terminal A selects an optimum terminal as a master terminal apparatus from among the terminals that are candidates for the master terminal apparatus. Here, as an example, it is assumed that the terminal A selects the terminal C as a master terminal device.
(Time T207) The terminal A transfers the master authority to the terminal C.
(Time T208) The terminal C switches the operation of the own terminal from the slave operation to the master operation.

(Time T209) The terminal C notifies the terminal A that the master operation has been switched (master preparation completion).
(Time T210) The terminal A notifies the terminal B that the master authority has been transferred to the terminal C.
(Time T211) The terminal A switches the operation of the own terminal from the master operation to the slave operation. This completes the master authority transfer process. Thus, this sequence is completed.

  Thus, a slave terminal device capable of becoming a master terminal device can run as a master terminal device. However, if the slave terminal device has not completed synchronization with the master terminal device, the candidacy itself may not be performed.

  When the master terminal device does not manage the list of slave terminal devices, candidates for the master terminal device may be searched by broadcasting.

  Further, even when the local branch remains in the replica, when it is found that there is no contradiction between the data update of the master terminal device and the data update of the slave terminal device (for example, “◇◇” in the local tree in FIG. 4) The slave terminal device may run as a master. As a result, the slave terminal device can run as a master terminal device before data can be completely synchronized with the master terminal device. Thereby, since the slave terminal apparatus can shift to the master state from an earlier stage, the master terminal apparatus can transfer the master authority to the terminal apparatus that is less likely to be removed from the network at an earlier stage.

  In addition, when the slave terminal device is going to synchronize data from now on, if the master terminal device receives an inquiry as to whether or not it can become the master, the master terminal device again after a time corresponding to the data amount at the time of synchronization. The slave terminal device may be inquired as to whether or not it can become a master. At that time, the master terminal device may temporarily transfer the master authority to another terminal. As a result, even if the slave terminal device does not synchronize data with the master terminal device at a certain time, when the master terminal device makes an inquiry to the slave terminal device again later, the slave terminal device exchanges data with the master terminal device. If synchronization is established, the master terminal device can be run. Thereby, it becomes easy to transfer master authority to a terminal with high capability as a master terminal device.

  As described above, in the first embodiment, the detection unit 130 included in the master terminal device can detect that the master terminal device may be disconnected from the network. When the detection unit 130 detects that the master terminal device may be disconnected from the network, the synchronization control switching unit 162 included in the master terminal device switches the operation of the own terminal from the master operation to the slave operation. When the detection unit 130 of the master terminal device detects that the master terminal device may be removed from the network, and the master terminal device inquires whether the master authority can be transferred, the synchronization control switching unit 162 included in the slave terminal device The operation of the own terminal is switched from the slave operation to the master operation. Thereby, when there is a possibility that the master terminal device is disconnected from the network, the master authority can be transferred to the slave terminal device in advance. As a result, the time at which the synchronization service between the master and the replica is interrupted in time can be eliminated or shortened, and the stability of the synchronization service between the master and the replica can be improved.

<Second Embodiment>
Next, the second embodiment will be described. FIG. 7 is a schematic block diagram showing the configuration of the information sharing system 1b in the second embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the information sharing system 1b in FIG. 7 is a configuration in which the terminal devices 100-1 to 100-3 are changed to the terminal devices 100b-1 to 100b-3 with respect to the configuration of the information sharing system 1 in FIG. ing. Here, the terminal devices 100b-1 to 100b-3 are collectively referred to as the terminal device 100b.

  FIG. 8 is a schematic block diagram illustrating a configuration of the terminal device 100b according to the second embodiment. Elements common to those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the terminal device 100b in FIG. 8 is a configuration in which the control unit 160 is changed to the control unit 160b with respect to the configuration of the terminal device 100 in FIG. And the control part 160b is the structure to which the determination part 161 was added compared with the control part 160 in 1st Embodiment.

The determination unit 161 receives the detection result detected by the detection unit 130. When the own terminal is in the master state, the determination unit 161 determines whether or not the own terminal may be removed from the network based on the detection result detected by the detection unit 130. For example, the determination unit 161 determines whether or not the own terminal may be disconnected from the network based on whether or not the external power supply is connected. Specifically, for example, when the determination unit 161 detects that the detection unit 130 has been disconnected from the external power source (for example, has been disconnected from the AC power source), that is, has switched to battery driving, It is determined that there is a possibility of detachment from the network. The determination unit 161 outputs the determination result to the synchronization control switching unit 162.
For example, when the detection unit 130 detects that the own terminal is being driven by the battery and the remaining battery level detected by the detection unit 130 is smaller than a predetermined threshold, the determination unit 161 determines that the own terminal is connected to the network. It may be determined that there is a possibility of deviating from the above.

  Further, the determination unit 161 may determine whether or not the own terminal may be removed from the network based on the physical state of the own terminal, for example. Specifically, for example, the determination unit 161 determines, based on the acceleration detected by the detection unit 130, whether or not the own terminal has changed from a stationary state to a moving state, and the own terminal moves from the stationary state to the movement state. When the state changes to a certain state, it may be determined that the terminal itself may be disconnected from the network. Specifically, for example, when the magnitude of the acceleration detected by the detection unit 130 is larger than the threshold acceleration, the determination unit 161 may determine that the own terminal may be disconnected from the network. For example, the determination unit 161 may determine that the terminal itself may be disconnected from the network when the duration of the acceleration change detected by the detection unit 130 is longer than a predetermined threshold time. This means that the determination unit 161 truncates the information when the movement does not continue for a certain period of time.

  For example, when the determination unit 161 detects that the wireless communication state has deteriorated from a predetermined reference, the determination unit 161 may determine that the terminal itself may be disconnected from the network. For example, when the RSSI is smaller than a predetermined threshold reception intensity, the determination unit 161 may determine that the own terminal may be disconnected from the network. This is because when the RSSI is small, it can be considered that the wireless state has deteriorated. Further, the determination unit 161 may determine that the own terminal may be disconnected from the network when the SNR is smaller than a predetermined threshold SNR. This is because when the SNR is small, it can be considered that the wireless state has deteriorated. Further, the determination unit 161 may determine that the own terminal may be disconnected from the network when the link speed is slower than a predetermined threshold speed. This is because when the link speed is low, it can be considered that the wireless state has deteriorated.

  Moreover, the determination part 161 may determine whether there exists a possibility that an own terminal may remove | deviate from a network based on the presence or absence of terminal operation. For example, when the duration of the terminal operation is shorter than a predetermined threshold time, the determination unit 161 may move with the user of the own terminal, so that the own terminal may be removed from the network. You may judge. This means that the determination unit 161 truncates the information when the operation does not continue for a certain period of time.

Further, when the detection unit 130 obtains a plurality of types of detection results and the determination unit 161 accepts the plurality of types of detection results, the determination unit 161 may perform the following processing. The determination unit 161
If at least one of disconnection from an external power source, movement of the terminal, deterioration of the wireless communication state, or user operation is detected, it may be determined that the terminal may be disconnected from the network. Moreover, the determination part 161 may determine with a possibility that an own terminal may remove | deviate from a network, when the detection part 130 detects a predetermined detection result simultaneously. For example, the determination unit 161 may determine that the own terminal may be disconnected from the network when the own terminal is switched to battery driving and a motion is detected by the acceleration sensor. For example, the determination unit 161 may determine that the own terminal may be disconnected from the network when the acceleration sensor detects a movement and a terminal operation is performed.

  In addition, for example, the determination unit 161 calculates a weighted sum for a plurality of detection results detected by the detection unit 130, and if the calculated weighted sum is equal to or greater than a predetermined threshold score, the own terminal is disconnected from the network. It may be determined that there is a possibility. Thereby, since the determination part 161 can perform a precise determination, it can improve the estimation precision of possibility that a self-terminal will remove | deviate from a network.

  For example, the determination unit 161 sets the weighting to 1 point for the power state, 2 points for acceleration, 1 point for terminal operation, 2 points for the threshold value, and the weighted sum is equal to or greater than the threshold point number (that is, 2 points). It may be determined that there is a possibility of being disconnected from the network. In that case, for example, when the acceleration sensor detects a motion, the determination unit 161 may determine that the own terminal may be removed from the network because the weighted sum is two points and is equal to or greater than the threshold score. For example, if the determination unit 161 is disconnected from the AC power source and the terminal is operated, the weighted sum is 2 points and is equal to or greater than the threshold score, so that the determination unit 161 may determine that the own terminal may be disconnected from the network. . For example, when the determination unit 161 is disconnected from the AC power source, the weighted sum is 1 point and is less than the threshold score, and therefore, the determination unit 161 may determine that the terminal itself is not likely to be disconnected from the network. For example, when the terminal is operated, the determination unit 161 may determine that there is no possibility that the own terminal is disconnected from the network because the weighted sum is 1 point and is less than the threshold score.

  As described above, in the second embodiment, the determination unit 161 determines whether the external terminal is connected, the battery level of the terminal, the estimated remaining operation time of the terminal, the physical state of the terminal, the wireless communication state, or the user operation Based on at least one of the presence / absence of the presence / absence, it is determined whether or not the own terminal is likely to be disconnected from the network. Thereby, in addition to the effect of 1st Embodiment, the terminal device 100b may compare the detection result of the detection part 130 with a predetermined reference | standard (for example, threshold value), and a self-terminal may remove | deviate from a network. The estimation accuracy of can be improved.

<Third Embodiment>
Subsequently, a third embodiment will be described. FIG. 9 is a schematic block diagram showing the configuration of the information sharing system 1c in the third embodiment. Elements common to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the information sharing system 1c in FIG. 9 is a configuration in which the terminal devices 100-1 to 100-3 are changed to the terminal devices 100c-1 to 100c-3 with respect to the configuration of the information sharing system 1 in FIG. ing. Here, the terminal devices 100c-1 to 100c-3 are collectively referred to as a terminal device 100c.

  FIG. 10 is a schematic block diagram illustrating a configuration of the terminal device 100c when operating as a master terminal device in the third embodiment. Elements common to those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the terminal device 100c in FIG. 10 is obtained by changing the control unit 160 to the control unit 160c with respect to the configuration of the terminal device 100 in FIG. And the control part 160c is the structure by which the synchronous control switching part 162 was changed into the synchronous control switching part (switching part) 162c compared with the control part 160 in 1st Embodiment. In the figure, an arrow indicating a data flow and an arrow indicating a control signal flow are shown.

  In the first and second embodiments, the synchronization control switching unit 162 switches between the master synchronization control unit 163 and the slave synchronization control unit 164 so that the master synchronization control unit 163 and the slave synchronization control unit 164 operate simultaneously. Never do. On the other hand, in the third embodiment, the slave synchronization control unit 164 always operates, and the master synchronization control unit 163 and the slave synchronization control unit 164 operate in parallel even in the master state.

  When the own terminal is in the master state, the synchronization control switching unit 162c receives the output of the detection unit 130, and performs the master authority transfer process when the detection unit 130 detects that the own terminal may be removed from the network. Start. When the master authority transfer process is successful, the master synchronization control unit 163 is stopped.

  On the other hand, when the own terminal is in the slave state, the synchronization control switching unit 162c determines whether it is in a state where it can become the master terminal device when it detects that another terminal has started the master authority transfer process. When the synchronization control switching unit 162c is in a state where it can become the master terminal device, the synchronization control switching unit 162c notifies the other terminal that it is a candidate for the master terminal device. When the master authority is transferred, the synchronization control switching unit 162c starts the operation of the master synchronization control unit 163, and causes the slave synchronization control unit 164 to refer to the master synchronization control unit 163 of the own terminal.

The difference in data flow between when operating as a master terminal device and when operating as a slave terminal device will be described with reference to FIGS. 10 and 11. FIG. 11 is a schematic block diagram illustrating a configuration of a terminal device when operating as a slave terminal device in the third embodiment.
When the own terminal is in the master state, as indicated by an arrow A11 in FIG. 10, the slave synchronization control unit 164 exchanges data with the master synchronization control unit 163 for synchronization under the control of the synchronization control switching unit 162c. On the other hand, when the own terminal is in the slave state, as indicated by an arrow A12 in FIG. 11, the slave synchronization control unit 164 controls the communication unit 140 and the data under the control of the synchronization control switching unit 162c. Exchange. This is because the slave synchronization control unit 164 exchanges data with the master synchronization control unit 163 of another terminal having the master authority via the communication unit 140 for synchronization. When operating as a slave terminal device, the master synchronization control unit 163 stops operating. For this reason, as shown in FIG. 11, no data is exchanged between the master synchronization control unit 163 and the communication unit 140 or the storage unit 150.

  As described above, in the third embodiment, when the own terminal is in the slave state, the slave synchronization control unit 164 communicates with other terminal devices in the master state. When the master authority is transferred, the master synchronization control unit 163 starts to operate. Then, the slave synchronization control unit 164 starts communication with the master synchronization control unit 163 in its own terminal. As a result, the master synchronization control unit 163 simply switches the master synchronization control unit 163 to be referred between the master terminal and the slave state between the other terminal and the own terminal without changing the internal operation. be able to. Therefore, in addition to the effects of the first embodiment, it is possible to simplify the implementation of the slave synchronization control unit 164 as compared to the first embodiment.

  The master synchronization control unit 163 according to the first embodiment has a function of updating the data of the own terminal when the data in the own terminal is modified when the own terminal is the master. On the other hand, in the third embodiment, when the own terminal is the master and the data in the own terminal is modified, the slave synchronization control unit 164 has a function of updating the data of the own terminal. Therefore, the master synchronization control unit 163 according to the third embodiment does not need a function of updating the data of the own terminal, so that the circuit area can be made smaller than that of the master synchronization control unit 163 according to the first embodiment. Therefore, the terminal device 100c in the third embodiment can be made smaller in circuit scale than the terminal device 100 in the first embodiment.

<Fourth Embodiment>
Subsequently, a fourth embodiment will be described. FIG. 12 is a schematic block diagram illustrating a configuration of an information sharing system 1d according to the fourth embodiment. Elements common to those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof is omitted. The configuration of the information sharing system 1d in FIG. 12 is a configuration in which the terminal devices 100c-1 to 100c-3 are changed to the terminal devices 100d-1 to 100d-3 with respect to the configuration of the information sharing system 1c in FIG. ing. Here, the terminal devices 100d-1 to 100d-3 are collectively referred to as a terminal device 100d.

  FIG. 13 is a schematic block diagram illustrating the configuration of the terminal device 100d according to the fourth embodiment. Elements common to those in FIG. 10 are denoted by the same reference numerals, and a specific description thereof is omitted. The configuration of the terminal device 100d in FIG. 13 is the same as the configuration of the terminal device 100c in FIG. 10 except that the control unit 160c is changed to a control unit 160d. And the control part 160d becomes the structure by which the determination part 161 was added compared with the control part 160c in 3rd Embodiment. Here, since the determination part 161 is a structure common to the determination part 161 in 2nd Embodiment, the specific description is abbreviate | omitted. In the figure, an arrow indicating a data flow and an arrow indicating a control signal flow are shown.

  In the fourth embodiment, as in the second embodiment, the determination unit 161 determines whether the external terminal is connected, the battery level of the own terminal, the estimated remaining operation time of the own terminal, and the physical state of the own terminal. Then, based on at least one of the wireless communication state and the presence / absence of user operation, it is determined whether or not the own terminal is likely to be disconnected from the network. Thereby, in addition to the effects of the third embodiment, the terminal device 100d may cause the terminal device 100d to be disconnected from the network by comparing the detection result of the detection unit 130 with a predetermined reference (for example, a threshold value). The estimation accuracy of can be improved.

  A program for executing each process of the terminal device (100, 100b, 100c, or 100d) of each embodiment is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in a computer system. The various processes described above related to the terminal device (100, 100b, 100c, or 100d) may be performed by reading and executing.

  Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (Dynamic) in a computer system serving as a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time is also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design etc. of the range which does not deviate from the summary of this invention are included.

1, 1b, 1c, 1d Information sharing system 100, 100-1, 100-2, 100-3, 100b, 100b-1, 100b-2, 100b-3, 100c, 100c-1, 100c-2, 100c- 3, 100d, 100d-1, 100d-2, 100d-3 Terminal device 110 Input unit 111 Input button 112 Touch panel 120 Display unit 130 Detection unit 140 Communication unit 150 Storage unit 160, 160b, 160c, 160d Control unit 161 Determination unit 162 162c Synchronization control switching unit (switching unit)
163 Master synchronization control unit 164 Slave synchronization control unit 200 Access point

Claims (10)

An information sharing system comprising: a first terminal device that holds an original data; and one or more second terminal devices that synchronize the data with the first terminal device. ,
The first terminal device is:
A detection unit for detecting that the first terminal device may not be able to maintain a master operation;
A first switching unit that switches the operation of the first terminal device from a master operation to a slave operation when the detection unit detects that the first terminal device may not be able to maintain a master operation; ,
With
The second terminal device is:
A second switching unit configured to switch the operation of the second terminal device from the slave operation to the master operation when the detection unit detects that the first terminal device may not be able to maintain the master operation; Information sharing system provided. The first terminal device is:
The detection unit can detect that the first terminal device may be disconnected from the network;
The first switching unit switches the operation of the first terminal device from a master operation to a slave operation when the detection unit detects that the first terminal device may be disconnected from the network,
The second switching unit switches the operation of the second terminal device from a slave operation to a master operation when the detection unit detects that the first terminal device may be disconnected from the network. 1. The information sharing system according to 1. When the first terminal device starts a process of transferring master authority, the second switching unit determines whether or not the own terminal device is in a state of becoming a master, and the own terminal device is in a state of becoming a master. If the master terminal is transferred from the first terminal device, the operation of the second terminal device is changed from the slave operation. The information sharing system according to claim 1, wherein the information sharing system is switched to a master operation. The detection unit detects at least one of disconnection from an external power source, a decrease in remaining battery capacity, a decrease in remaining operable time, a movement of the own terminal, a deterioration in wireless state, and a user operation. 4. The information sharing system according to any one of items 1 to 3. The terminal device used in an information sharing system comprising a terminal device that holds an original data, and one or more slave terminal devices that synchronize the data with the terminal device,
A detection unit that detects that the terminal device may not be able to maintain a master master status,
Based on the detection result detected by the detection unit, a switching unit that switches the operation of the terminal device from the master operation to the slave operation,
A terminal device comprising: The terminal device used in an information sharing system comprising a master terminal device that holds an original data, and one or more terminal devices that synchronize the master terminal device and the data,
A terminal device comprising a switching unit that switches the operation of the own terminal device from a slave operation to a master operation when the master terminal device detects that the master terminal device may not be able to maintain a master operation. Used in an information sharing system comprising a first terminal device that holds an original data, and one or more second terminal devices that synchronize the data with the first terminal device A switching method executed by the first terminal device,
A step of detecting that the detection unit may not be able to maintain a state in which the terminal device is a master;
A step of switching the operation of the terminal device from the master operation to the slave operation based on the detection result detected by the detection unit;
A switching method. Used in an information sharing system comprising a first terminal device that holds an original data, and the first terminal device and one or more second terminal devices that synchronize the data A switching method executed by the second terminal device,
When the first terminal device detects that the first terminal device may not be able to maintain the master operation, the switching unit switches the operation of the own terminal device from the slave operation to the master operation. Having a switching method. Used in an information sharing system comprising a first terminal device that holds an original data, and one or more second terminal devices that synchronize the data with the first terminal device In the first terminal device,
A detection step for detecting that the terminal device may not be able to maintain a master state;
Based on the detection result detected by the detection step, a switching step of switching the operation of the own terminal device from the master operation to the slave operation,
A program for running Used in an information sharing system comprising a first terminal device that holds an original data, and one or more second terminal devices that synchronize the data with the first terminal device In the second terminal device,
Switching step of switching the operation of the own terminal device from the slave operation to the master operation when the first terminal device detects that the first terminal device may not be able to maintain the master operation. A program for running

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