JP4635615B2 - Information processing apparatus, system, data synchronization method, and program - Google Patents

Description

  The present invention relates to an information processing device, a system, a data synchronization method, and a program, and more particularly, to an information processing device connected to a plurality of other information processing devices belonging to the same group via a communication line, and to the same group The present invention relates to an information processing system in which a plurality of information processing apparatuses are connected via a communication line, a data synchronization method applicable to the information processing system, and a data synchronization program for causing a computer to function as the information processing apparatus.

  2. Description of the Related Art Conventionally, a client / server system and a peer-to-peer (hereinafter referred to as P2P) system are known as forms of a network system for connecting information processing apparatuses such as computers to each other via a network. The client / server system is a system in which a server manages various information resources or executes services provided by various applications and is used by a client, and a master-slave relationship is fixed. On the other hand, in the P2P system, basically no dedicated server is provided, and each peer (for example, a personal computer) connected to the network provides a predetermined service to another peer in some cases. It is a system that operates like a server and in some cases operates like a client by using a service provided by another peer, and each peer has an equal relationship.

  By the way, in the client / server system, data (shared data) that each client may access is stored and managed by the server. However, in the P2P system, each peer has an equal relationship, and thus data sharing is realized. Several schemes are conceivable for this purpose. For example, in Patent Document 1, in a P2P network, a computer that performs file sharing holds only reference information related to a shared file, and when the shared file is updated, the reference information of the file held by each computer is updated to the latest file. Change to information indicating the computer that holds the file (the computer that holds the updated file), and when the user accesses the file, another computer on the network that holds the file based on the reference information A technique is disclosed in which the latest file can be displayed at any time by accessing and downloading the file.

 Also, in Patent Document 2, a plurality of computers each having a transfer memory area for sharing data is connected to a network, and each computer periodically transfers data in its own computer area in the transfer memory area to another computer. A system in which a computer that broadcasts and receives broadcast data stores the data in a corresponding computer area in the transfer memory area so that the contents of the transfer memory area are matched between the computers and the data is shared Broadcasts received periodically by counting the number of times broadcast data is received and notifying the reception only when a predetermined number of times is reached, and discarding the received data otherwise A technique for thinning out data is disclosed.

In Patent Document 3, a document shared between computers is managed by an identifier indicating a computer that holds the original of the document and an update history, and updated when the document is updated in a network. The document is transmitted to the computer that holds the original of the document, the update history is stored, and at the same time, the copy processing (redistribution) is performed on the other computer that holds the document, so that A technique is disclosed that enables the entire network to share the latest document wherever the document is updated.
JP 2003-006032 A Japanese Patent Application Laid-Open No. 07-219902 JP 2003-256259 A

  However, in the technique described in Patent Document 1, the first computer holds the latest specific shared data at the timing when the first computer performs processing for displaying the specific shared data that the user is trying to access. When the first computer performs the process of displaying the specific shared data, the first computer is connected to the second computer due to a communication line failure or the like. When the specific shared data cannot be downloaded from the user, there is a problem that the user cannot access the latest shared data.

  On the other hand, in the techniques described in Patent Documents 2 and 3, since the latest shared data is held in each computer, when the user accesses the shared data, the computer is not necessarily in a state where it can communicate with other computers. There is no need. However, in this method, when shared data is updated on a specific computer in a group of computers sharing data (referred to as a peer group in the P2P system), each computer other than the specific computer in the group It is necessary to perform processing for synchronizing the shared data by rewriting the held shared data to the updated data. In consideration of the possibility that communication with some computers in the group may be interrupted at the timing of performing synchronization processing, it is necessary to periodically perform processing for synchronizing shared data.

  On the other hand, since the technology described in Patent Document 2 periodically transmits the shared data itself, there is a problem that traffic in the system increases in order to synchronize the shared data. Since the technology also synchronizes the shared data by transmitting and receiving the shared data itself, the traffic in the system increases as this processing is performed periodically. Further, in the technologies described in Patent Documents 2 and 3, since the process of receiving the shared data itself is periodically performed in the computer that receives the shared data, the load on the computer on the receiving side increases. There is also a problem. Furthermore, in the technique described in Patent Document 3, since the updated shared data is redistributed via a computer that holds the original of the shared data, the load on the computer that holds the original of the shared data increases. There is also a problem of.

  The present invention has been made in view of the above facts, and it is possible to achieve synchronization of shared data held by each information processing device belonging to the same group while suppressing an increase in traffic and load. It is an object to obtain a possible information processing apparatus, information processing system, data synchronization method, and data synchronization program.

An information processing apparatus according to a first aspect of the present invention is an information processing apparatus connected to a plurality of other information processing apparatuses belonging to the same first group as its own apparatus via a communication line, A storage unit capable of storing shared data that should be held by each information processing device belonging to the group and to be synchronized with each other, and a specific information processing device belonging to the first group are held by the specific information processing device. If you are the shared data received notification information for notifying that it has been updated, after the wait time determined at random has passed, it acquires for transmitting an acquisition request for the shared data to the specific information processing apparatus A requesting unit, receiving the shared data transmitted from the specific information processing apparatus based on the acquisition request transmitted by the acquisition requesting unit, and storing the received shared data in the storage unit It includes a receiving unit to be stored, a is configured.

The information processing apparatus according to the first aspect of the present invention is connected to a plurality of other information processing apparatuses belonging to the same first group as the own apparatus via a communication line, and each information processing belonging to the first group The apparatus includes storage means capable of storing shared data that each device should hold and synchronize with each other. Here, in the first aspect of the invention, when notification information for notifying that the shared data held by the specific information processing apparatus has been updated is received from the specific information processing apparatus belonging to the first group to, the acquisition requesting means, after the wait time determined at random has passed, the acquisition request of the shared data is transmitted to a particular information processing apparatus. The receiving unit receives the shared data transmitted from the specific information processing apparatus based on the acquisition request transmitted by the acquisition request unit, and stores the received shared data in the storage unit. Thus, the process of synchronizing the shared data stored in the storage unit of the information processing apparatus according to the first aspect of the invention is completed.

Thus, in the first aspect of the present invention, when receiving the notification information to notify that the shared data which a particular information processing apparatus holds are updated, wait time determined at random has passed Later, since the shared data acquisition request is transmitted to the specific information processing apparatus, even if the specific information processing apparatus in which the shared data is updated transmits the notification information to the plurality of information processing apparatuses belonging to the first group, The specific information processing apparatus receives the notification information at a timing shifted from each other from the plurality of information processing apparatuses that transmitted the notification information, and the load on the traffic and the specific information processing apparatus is concentrated at one time and excessive. Can be prevented. Therefore, according to the first aspect of the present invention, it is possible to achieve synchronization of shared data held by each information processing apparatus belonging to the same group while suppressing an increase in traffic and load.

Incidentally, when a particular information processing apparatus has transmitted the notification information, considering that there is a possibility that communication with the part of the particular information processing apparatus and another information processing apparatus is interrupted, claim 1 Also in the described invention, it is desirable that notification information is repeatedly transmitted from a specific information processing apparatus at an arbitrary time interval. As described above, this notification information is an individual information processing that has received the notification information. It is desirable that the apparatus is information that can determine whether the shared data held by each individual information processing apparatus is data before update. In this case, acquisition requesting means, for example, as described in claim 2, when a new shared data in the storage means is not stored (e.g., the information processing apparatus according to the invention of claim 1, wherein the the first group Specified when the shared data is not received due to participation, etc., and the shared data stored in the storage means is determined to be the pre-update data based on the received notification information When the acquisition request is transmitted to the information processing apparatus and it is determined that the shared data stored in the storage unit is the updated data, the acquisition request is preferably not transmitted. As a result, the information processing apparatus according to the first aspect of the present invention does not need to transmit a shared data acquisition request each time notification information is received, so that an increase in traffic can be suppressed.

The information processing apparatus according to the invention of claim 1 wherein, together with belong to the second group comprises a first group, the other both a plurality of information processing devices belonging to the second group do not belong to the first group Although it may be connected via a communication line, in this case, for example, as described in claim 3 , the receiving means should be held by each information processing apparatus belonging to the second group and synchronized with each other After the shared data to be received is received from the specific information processing apparatus and stored in the storage means, the notification information for notifying that the shared data has been updated is sent to all other members belonging to the second group and not belonging to the first group. The second notification means for transmitting to the information processing apparatus, and the shared data stored in the storage means each time the second notification means receives an acquisition request for shared data from the information processing apparatus that has transmitted the notification information. And a second transmission means for transmitting to the acquisition request source of the information processing apparatus, it is preferable to further provide a.

For example, when shared data that each information processing device belonging to a specific group should hold and synchronize with each other is updated by a specific information processing device belonging to the specific group, a large number of information processing devices exist in the specific group. Suppose that each information processing device that has received notification information from a specific information processing device belonging to a specific group transmits an acquisition request after waiting for a different waiting time, as described in claim 1. However, there is a possibility that the load applied to a specific information processing apparatus is concentrated at one time and becomes excessive.

On the other hand, in the invention described in claim 3 , the shared data that each information processing apparatus belonging to the second group corresponding to the specific group should hold and synchronize with each other is the second group (and the second group). if it is updated in a particular information processing apparatus belonging to the first group) which is included in the group, information according to claim 3, wherein the specific information processing apparatus the information processing apparatus belonging to the first group (the information processing apparatus If the notification information is transmitted only to the processing device (including the processing device), the shared data is transmitted based on the acquisition request (processing for synchronizing the shared data held by each information processing device belonging to the first group). by the information processing apparatus according to the invention of claim 3, wherein the transmission of the notification information to the information processing apparatus belonging to the second group do not belong to the first group, the shared data based on the acquisition request So that the transmission (processing for synchronizing the shared data does not belong to the first group each information processing apparatus belonging to the second group are held) is performed. Therefore, according to the third aspect of the present invention, when shared data that should be held by each of a number of information processing apparatuses and synchronized with each other is updated, the information processing apparatus that has updated the shared data is updated. It is possible to avoid applying a great load.

In the third aspect of the present invention, the second notifying unit does not belong to the first group for the shared data notified of the update by receiving the notification information from another information processing apparatus belonging to the first group. The notification information may always be transmitted to other information processing apparatuses belonging to the two groups, and attribute information indicating the data to be shared in which group is added to each shared data. When the attribute information indicating that the data is shared in the second group is added to the shared data notified of the update by receiving the notification information from another information processing apparatus belonging to the first group. only, as may be configured to transmit the notification information to another information processing apparatus belonging to the second group do not belong to the first group, but instead of this, as described for example in claim 4, especially If the shared data updated by the information processing apparatus is data that each information processing apparatus belonging to the second group should hold and synchronize with each other, the notification information transmitted from the specific information processing apparatus Is added with identification information indicating that the shared data is data that each information processing device belonging to the second group should hold and synchronize with each other, and the second notification means receives from the specific information processing device Only when the identification information is added to the notified information, the notification information may be transmitted to all other information processing apparatuses belonging to the second group and not belonging to the first group.

An information processing system according to claim 5 is an information processing system in which a plurality of information processing devices belonging to the same first group are connected via a communication line, wherein the plurality of information processing devices Each of the information processing devices belonging to the first group should be held and synchronized with each other, and the shared data stored in the storage means has been updated. In this case, first notification means for transmitting notification information for notifying that the shared data has been updated to all other information processing devices belonging to the first group, and the first notification means for transmitting notification information. Each time the shared data acquisition request is received from the acquired information processing apparatus, the shared data stored in the storage means is transmitted to the acquisition request transmission source information processing apparatus. Randomly determined when receiving notification information for notifying that the shared data held by the specific information processing device has been updated from the communication means and the specific information processing device belonging to the first group after between the standby has elapsed, transmitting the acquisition request of the shared data acquisition requesting means for transmitting to the particular information processing apparatus, from the specific information processing apparatus based on the acquisition request the acquisition requesting means sends And receiving means for receiving the received shared data and storing the received shared data in the storage means.

In the information processing system according to the fifth aspect of the present invention, each of the plurality of information processing apparatuses belonging to the first group includes the storage unit, the first notification unit, the first transmission unit, the acquisition request unit, and the reception unit. since each comprise a either even if the shared data is updated by the information processing apparatus, similarly to the inventions of claim 1 wherein each information belonging to the same group among the plurality of information processing apparatus Synchronizing the shared data held by each processing device can be realized while suppressing an increase in traffic and load.

According to a sixth aspect of the present invention, there is provided a data synchronization method comprising a plurality of information processing devices belonging to the same first group connected via a communication line, wherein the plurality of information processing devices are connected to the first group. In the information processing system provided with storage means capable of storing shared data that should be held by each information processing apparatus belonging to each other and synchronized with each other, the sharing stored in the storage means of the specific information processing apparatus When data is updated, the specific information processing apparatus transmits notification information notifying that the shared data has been updated to all other information processing apparatuses belonging to the first group, and the specific information processing apparatus individual information processing apparatus, after the wait time determined at random has passed, the specific information acquisition request of the shared data from the information processing apparatus has received the notification information Each time the specific information processing apparatus receives the shared data acquisition request from the information processing apparatus that has transmitted the notification information, the specific information processing apparatus is stored in the storage unit of the specific information processing apparatus. The shared data transmitted from the specific information processing apparatus based on the acquisition request, to each of the information processing apparatuses that transmitted the acquisition request. receiving data, because to store the shared data received in the storage means, like the inventions of claim 1, wherein, to synchronize the shared data identical each information processing apparatus belonging to the group are each held Can be realized while suppressing an increase in traffic and load.

A data synchronization program according to claim 7 is connected to another plurality of information processing devices belonging to the same first group as the own device via a communication line, and each information processing device belonging to the first group When the shared data stored in the storage means is updated, the shared data is updated when the computer having storage means capable of storing the shared data that should be held and synchronized with each other is updated. First notification means for transmitting notification information for notification to all other information processing devices belonging to the first group, and an acquisition request for the shared data from the information processing device to which the first notification means has transmitted notification information The first transmission unit that transmits the shared data stored in the storage unit to the information processing apparatus that is the acquisition request transmission source, When the notification information for notifying that the shared data held by the specific information processing apparatus is updated is received from the specific information processing apparatus, the waiting time randomly determined or the first group Acquisition request means for transmitting the shared data acquisition request to the specific information processing apparatus after a standby time set in advance so as to be different for each individual information apparatus belonging to the information processing apparatus, and the acquisition request means The shared data transmitted from the specific information processing apparatus is received based on the acquisition request transmitted by the server, and functions as a receiving unit that stores the received shared data in the storage unit.

According to a seventh aspect of the present invention, there is provided a data synchronization program that is connected to a plurality of other information processing devices belonging to the same first group as its own device via a communication line, and each information processing device belonging to the first group A program for causing a computer provided with storage means capable of storing shared data to be held and synchronized with each other to function as the first notification means, the first transmission means, the acquisition request means, and the reception means. since, by executing the data synchronization program which the computer according to the invention of claim 7, wherein, the computer becomes to function as an information processing equipment according to claim 1, originating in claim 1, wherein Like the bright, to take the synchronization of the shared data the same belonging to the group each information processing apparatus are each held, while suppressing an increase in traffic or load actual It can be.

The present invention provides a notification for notifying that the shared data has been updated from a specific information processing apparatus that holds shared data that each information processing apparatus belonging to the first group should hold and synchronize with each other. when receiving the information, after the wait time determined at random has passed, it transmits an acquisition request for the shared data to a specific information processing apparatus is transmitted from a particular information processing apparatus based on the transmitted acquisition request Since the received shared data is received and the received shared data is stored in the storage means, it is possible to synchronize the shared data held by each information processing device belonging to the same group, thereby increasing traffic and load. It has the outstanding effect that it can implement | achieve, suppressing this.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
In the following, a P2P network (P2P system) suitable for the present invention will be described first. As shown in FIG. 1, the P2P network 10 has a configuration in which the peers 12A to 12G are virtually connected to each other. In practice, for example, the peers 12A to 12C are peers whose access is restricted by the firewall 14. The peers 12C to 12E may be peers connected to the Internet, and the peers 12E to 12G may be peers whose addresses are translated by NAT (Network Address Translation).

  Here, a peer refers to communication with other electronic devices such as a computer such as a personal computer, a PDA (Personal Digital Assistance), a mobile phone, a printer, a copier, and a multifunction device having a plurality of these functions. Any of various electronic devices having a function to be performed may be used, and each peer refers to hardware of a corresponding electronic device or software that realizes a function of the corresponding electronic device. Each peer can participate in the P2P network regardless of whether it is the same type of device or a different type of device. There are various connection methods between peers. For example, TCP (Transmission Control Protocol) connection using IPv4 (Internet Protocol version 4) and IPv6 (Internet Protocol version 6) functions, HTTP (HyperText Transfer Protocol), SMTP (Simple Mail Transfer Protocol) can be used.

  As a form of the P2P network, as shown in FIG. 2, a pure P2P in which all of the peers 14A to 14K are in an equal relationship and a server 14S as shown in FIG. There is a hybrid P2P configuration in which the peers 14A to 14H are realized in an equal relationship with respect to provision of other services to the server 14S, and the present invention is applicable to any configuration.

  Moreover, as shown in FIG. 4 as an example, users or peers who log on to each peer participating in the P2P network can form a group according to the purpose. In FIG. 4, all of peers 12A to 12G belong to group 1, peers 12A, 12C, 12E, and 12F belong to group 2, and peers 12B, 12E, 12F, and 12G belong to group 3. Each user or peer may belong to a single group or may belong to a plurality of groups. Also, a user or peer does not necessarily have to belong to a group.

  FIG. 5 shows a basic configuration of individual peers participating in the P2P network 10. As shown in FIG. 5, the peer 12 includes a P2P infrastructure configuration unit 16, a P2P infrastructure management data storage unit 18, an application execution unit 20, and an application memory 22, and the P2P infrastructure configuration unit 16 performs message control. Unit 24, data management unit 26, transmission unit 28, and reception unit 30. The transmission unit 28 transmits the message received from the message control unit 24 toward the network 32. The receiving unit 30 receives data necessary for its own peer among data transmitted and received in the P2P network 10. The reception unit 30 is always in a reception standby state, receives various requests and data from other peers of the P2P network 10, and passes them to the message control unit 24. The receiving unit 30 operates independently and in parallel with the transmitting unit 28.

  FIG. 6 shows a schematic configuration of the message control unit 24. As shown in FIG. 6, the message control unit 24 includes a service execution unit 34 and a message dispatch unit 36. The service execution unit 34 includes a peer search service unit 38, a notification information disclosure service unit 40, a notification information acquisition service unit 42, a group management service unit 44, a user management service unit 46, and a peer management service unit 48. Each service unit executes each service while transmitting and receiving information to and from each other. The peer search service unit 38 has a function of searching for a peer participating in the P2P network and a function of searching for a peer that can provide a service (function) required by the peer. The search range can be controlled by designating the name and attribute of the required service, the threshold value for the number of hops, and the like. Here, the number of hops is the number of peers through which a message is transmitted.

  The notification information disclosure service unit 40 has a function of publishing information such as services that can be provided by its own peer on the P2P network as notification information. Here, the services that can be provided include, for example, a group management service and a user management service, which will be described later, in addition to an application executed by the application execution unit 20. The announcement information may be disclosed, for example, when there is an inquiry from another peer, when the own peer is activated, or periodically. In this way, the announcement information is published on the P2P network by the announcement information disclosure service unit 40 of each peer, so what kind of service each peer participating in the P2P network can use on the P2P network can be determined. I can grasp it.

  The notification information acquisition service unit 42 acquires the notification information transmitted from the peer searched by the peer search service unit 38 or the notification information spontaneously transmitted from another peer, and passes it to the data management unit 26. The data management unit 26 stores the acquired notification information in the P2P infrastructure management data storage unit 18 as peer information. Thereby, each peer can grasp what kind of service other peers participating in the P2P network provide. In addition, the group management service unit 44 has a function of managing participation and withdrawal from a group composed of peers having the same purpose, generation of a new group, and the like based on group information. The group information is, for example, information representing a correspondence relationship between at least a group ID and a user ID, and is stored in the P2P infrastructure management data storage unit 18. By referring to this group information, it is possible to grasp which user belongs to which group.

  The user management service unit 46 has a function of managing user information. User information includes, for example, logon information indicating the correspondence between a peer ID and a user ID logged on to the peer, information about the user himself such as the user name and email address, and the group ID of the group to which the user belongs. Information is stored in the P2P infrastructure management data storage unit 18. The peer management service unit 48 has a function of managing peer information of peers participating in the P2P network. The message dispatch unit 36 analyzes a message from the application execution unit 20 and a message transmitted / received to / from another peer, and passes control to a service unit that should perform processing related to the analyzed message in the service execution unit 34. .

  On the other hand, the P2P infrastructure management data storage unit 18 stores route information 18A, group information 18B, adjacent information 18C, peer information 18D, and user information 18E. The path information 18A includes information on a path in the P2P network, for example, information on a spanning tree (a message transfer path having a tree structure without a loop). As described above, the group information 18B is information representing a correspondence relationship between at least a group ID and a user ID, for example. The adjacency information 18C includes information on a peer adjacent to the own peer, for example, information such as a peer ID. Here, the adjacent peer can be, for example, a peer within a predetermined time that is a response time for a packet transmitted from the own peer. The adjacent information can be generated based on a response time obtained in a process of communicating with another peer, for example, but may be set manually by an operator's operation or the like. The peer information 18D is information related to the peer searched by the peer search service unit 38, for example, information such as a peer ID, information related to a service provided by each peer on the P2P network acquired by the notification information acquisition service unit 42, etc. including. Here, for example, an IP address or a URI (Uniform Resource Identifier) can be used as the peer ID. As described above, the user information 18E includes user logon information, information about the user himself, and the like.

  The application execution unit 20 executes various applications, and transmits and receives messages to and from other peers via the message control unit 24. The application memory 22 is a memory for storing various types of information related to the execution of the application execution unit 20.

Next, as a specific example of application execution, each peer belonging to a certain peer group (referred to as peer group A for convenience) stores the same data (shared data) in each peer's nonvolatile storage means (for example, HDD) (Hard Disk Drive) etc.) When the shared data stored in a certain peer is updated in the state where each is stored, the processing executed by the application execution unit 20 of each peer (the shared data is synchronized) Will be described. The process of synchronizing the shared data is performed by executing the shared data distribution process (FIG. 8) in the peer application execution unit 20 in which the shared data has been updated, and the application execution units of other peers belonging to the peer group A. 20, the shared data synchronization program (FIG. 9) is executed. The shared data distribution program and the shared data synchronization program for performing these processes correspond to the data synchronization program according to claim 7. And pre-installed on individual peers. Each peer belonging to the peer group A corresponds to the information processing apparatus according to the present invention, and the peer group A corresponds to the information processing system according to claim 5 . The nonvolatile storage means described above corresponds to the storage means according to the present invention, and the peer group A corresponds to the first group according to the present invention.

  As shown in FIG. 7A as an example, when shared data is updated at an arbitrary peer in peer group A (FIG. 7 shows an example in which shared data is updated at peer 2 as an example. In the peer application execution unit 20, the shared data distribution process shown in FIG. 8 is executed. This shared data distribution process is executed not only when the shared data is updated, but also when the transmission timer times out and when an acquisition request is received from another peer. Therefore, in step 100, it is first determined whether or not the current activation factor is an update of shared data. If the determination is affirmative, the process proceeds to step 102, where 1 is substituted into the number i of transmissions of the updated shared data X, and in the next step 104, the identifier x of the updated shared data X is acquired.

  In step 106, a digest (hash value) of the shared data X is generated using a hash function. In step 108, update notification information of the shared data X including the identifier x acquired in step 104, the digest generated in step 106, and transmission source information (own peer ID) is generated and stored in the application memory 22. In step 110, the information stored in the P2P infrastructure management data storage unit 18 is referred to, and all peers (peers other than the own peer) belonging to the peer group A sharing the shared data X are recognized as transmission targets. In step 112, the update notification information of the shared data X stored in the application memory 22 in the previous step 108 is transmitted to all the peers recognized in step 112 (see also FIG. 7B).

  In step 114, the transmission time interval in the i-th update notification information transmission is captured, and in the next step 116, a transmission timer for the shared data X having the captured transmission time interval as a timer value is started, and the process ends. As an example, as shown in FIG. 9, in this embodiment, the relationship between the number of transmissions of update notification information and the communication time interval so that the communication time interval of update notification information increases as the number of times of transmission of update notification information increases. The transmission time interval is relatively shortened in the first transmission of the update notification information.

When the transmission timer interval started in step 116 times out due to the elapse of the time corresponding to the transmission time interval captured in step 114 after completing the transmission of the i-th update notification information, the shared data distribution process is restarted. Then, the determination at the previous step 100 is denied and the routine proceeds to step 120, where it is determined whether or not the current activation factor is a timeout of the transmission timer. In this case, the determination is affirmed and the routine proceeds to step 122, where the shared data X corresponding to the transmission timer that has timed out is first recognized. In step 124, the number of times i of transmission of the shared data X is incremented by 1. In the next step 126, the update notification information of the shared data X stored in the application memory 22 is read, and the process proceeds to step 110. As a result, the update notification information for notifying the update of the shared data X is retransmitted to all the other peers belonging to the peer group A as described above, and the transmission timer for the shared data X corresponds to the current transmission count i. Will be restarted with a new timer value. By retransmitting the update notification information, even if communication with some peers in the peer group A is temporarily interrupted, it is surely notified to the some peers that the shared data X has been updated. can do. Note that steps 100 to 126 described above corresponds to the first notification hand stage according to the present invention.

  The update notification information transmitted in the shared data distribution process is information for notifying other peers that the shared data X has been updated, and is composed of information such as an identifier x, a digest, and transmission source information. The amount of data is significantly smaller than the shared data X itself. Therefore, even if the update notification information is periodically transmitted to all other peers belonging to the peer group A, the traffic increase in the peer group A is negligible, and the update notification information is received to receive the other information. It is also possible to avoid a significant increase in the peer load. In addition, the transmission time interval of the update notification information is made shorter than the transmission time interval when the shared data itself is transmitted because the influence on the traffic and load is small compared with the case where the shared data itself is transmitted. It is also possible. As a result, even if other peers belonging to peer group A include a peer that could not receive the update notification information that was initially transmitted due to the influence of a communication line failure or the like, It is possible to shorten the average time until it is recognized that has been updated.

  Next, processing in the peer that receives the update notification information will be described. When the update notification information is received from another peer, the application execution unit 20 of the peer executes the shared data synchronization process shown in FIG. This shared data synchronization processing is executed not only when the update notification information is received but also when the transmission timer times out and when shared data is received from another peer. Therefore, in step 150, it is first determined whether or not the current activation factor is reception of update notification information. If the determination is affirmative, the process proceeds to step 152, and the identifier x of the updated shared data is extracted from the received update notification. In step 154, based on the identifier x extracted in step 152, it is determined whether or not the corresponding shared data X is already stored in the non-volatile storage means of the own peer.

  As explained earlier, each peer can join a new peer group or withdraw from a peer group that has joined, such as immediately after its own peer joined peer group A. In some cases, the shared data X may not be stored in the non-volatile storage unit of the own peer when the update notification information is received. In this case, the determination at step 154 is negative and the routine proceeds to step 160. On the other hand, if the shared data X is stored in the non-volatile storage unit of the own peer, the determination in step 154 is affirmed and the process proceeds to step 156, and the non-volatile storage unit of the own peer is used using the hash function. A digest (hash value) of the shared data X stored in is generated. In step 158, a digest is extracted from the received update notification information. In step 159, the digest generated in step 156 is checked against the digest extracted in step 158 to determine whether or not they match.

  If the determination in step 159 is negative, it can be determined that the shared data X stored in the non-volatile storage means of the peer is the data before update, so the process proceeds to step 160 and the update notification information transmission source In order to request the peer to transmit the shared data X, the shared data X acquisition request information including the identifier x extracted in step 152 and the request source information (the own peer ID) is generated. In step 162, the generated shared data X acquisition request information is stored in the application memory 22 in association with the transmission source information extracted from the received update notification information (the ID of the peer of the update notification information transmission source). In step 164, a time for waiting for transmission of the acquisition request information for shared data X is determined by a random number. In next step 166, the acquisition request information for shared data X using the transmission standby time determined in step 164 as a timer value. The transmission timer is started and the process ends.

When the transmission standby time determined in step 164 elapses and the transmission timer started in step 166 times out, the shared data synchronization process is started again, the determination in step 150 is denied, and the process proceeds to step 170. Then, it is determined whether or not the current activation factor is a timeout of the transmission timer. In this case, the determination is affirmed, and the process proceeds to step 172. First, the shared data X corresponding to the transmission timer that has timed out is recognized. In step 174, the acquisition request information and transmission source information of the shared data X stored in the application memory 22 in the previous step 162 are read. In the next step 176, the read transmission request information of the shared data X is read. The information is transmitted to the peer corresponding to the original information (the update notification information transmission source peer), and the process ends. Steps 150 to 176 described above correspond to acquisition request means according to the present invention (specifically, the acquisition request means described in claim 2 ).

  As described above, when the acquisition request information of the shared data X is transmitted from the peer that has received the update notification information, and this acquisition request information is received by the update notification information transmission source peer, the update notification information transmission source peer is transmitted. Then, the shared data distribution process is started again, the determinations in steps 100 and 120 are respectively denied, and the process proceeds to step 130. In step 130, the identifier x is extracted from the received acquisition request information to recognize the acquisition target shared data X. In the next step 132, the recognized shared data X (updated data) is read from the non-volatile storage means of the own peer. In step 134, the shared data X read in step 132 is transmitted to the acquisition request transmission source peer together with the identifier x, and the process ends. Steps 130 to 134 described above correspond to the first transmission means according to the present invention.

  When the shared data X is received at the acquisition request transmission source peer, the shared data synchronization processing is started again at the acquisition request transmission source peer, the determinations of steps 150 and 170 are respectively denied, and the process proceeds to step 180. In step 180, based on the identifier x received together with the shared data X from the peer of the shared data transmission source, it is determined whether or not the corresponding shared data X is already stored in the non-volatile storage means of the own peer. When determination is denied, it transfers to step 182 and memorize | stores the received shared data X in the non-volatile memory | storage means of an own peer, and complete | finishes a process. If the determination in step 180 is affirmed, the process proceeds to step 184, and the received shared data X is overwritten and stored on the shared data X already stored in the non-volatile storage means of the own peer. Exit. Thereby, the synchronization for changing the shared data X stored in the nonvolatile storage means to the latest data is completed. Steps 180 to 184 described above correspond to the receiving means according to the present invention.

  In this embodiment, each time the update notification information transmission source peer receives the acquisition request information from another peer, it transmits the shared data requested to be acquired (steps 130 to 134). Each receiving peer transmits the acquisition request information after the transmission waiting time determined by the random number has elapsed, and therefore, as shown in FIG. 7C to FIG. 7E, for example, each peer that has received the update notification information The acquisition request information is transmitted at different timing from each other, and accordingly, the timing at which the shared data X is transmitted from the peer of the update notification information transmission source to each peer also differs. As a result, it is possible to prevent the traffic in the peer group A or the load applied to the update notification information transmission source peer from being excessively concentrated at one time, and to synchronize the shared data held by each peer belonging to the peer group A. It can be realized while suppressing an increase in traffic and load.

  In this embodiment, since the peer with updated shared data periodically transmits the update notification information, the peer on the receiving side of the update notification information receives the same update notification information multiple times. In this case, since the digest of the shared data X already stored in the non-volatile storage means (the digest generated in step 156) matches the digest extracted from the received update notification information, If the determination is affirmed, it can be determined that the shared data X stored in the non-volatile storage means of the peer is the updated data, and the process is terminated without performing any process. Thereby, the traffic in the peer group A can be suppressed, and it is also possible to avoid an increase in the load applied to the peer on the side receiving the update notification information.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. Since the second embodiment has the same configuration as that of the first embodiment, the same reference numerals are given to the respective parts, and the description of the configuration is omitted. Hereinafter, the shared data in the second embodiment is synchronized. Only the differences from the first embodiment will be described.

  In the first embodiment, when the shared data held by each peer belonging to a certain peer group is updated by any peer, the peer in which the shared data is updated may belong to the same peer group. The example in which the update notification information is transmitted to all the peers and the shared data is transmitted has been described. However, when the number of peers belonging to the peer group becomes large, each peer that has received the update notification information receives the acquisition request information. Even if the transmission timings are different from each other, there is a possibility that a great load is applied to the peer that transmits the update notification and the shared data.

On the other hand, in the P2P network, another peer group included in a certain peer group may be set like a peer group A and a sub-peer group a shown in FIG. In the second embodiment, when the sub-peer group a included in the peer group A is used and the shared data held in each peer in the peer group A is updated, the peer in which the shared data is updated is generated. Transmits the update notification information and the shared data only to other peers in the sub-peer group a, receives the update notification information, and completes the update (synchronization) of the shared data. The load applied to the peer in which the update of the shared data occurs by transmitting the update notification information and the shared data to other peers belonging to the peer group A and not belonging to the sub-peer group a. Has been reduced. In FIG. 11, it goes without saying that the peers 4 to 6 may belong to another sub-peer group. The sub-peer group a corresponds to the second group described in claim 3 .

In other words, in the shared data distribution processing according to the second embodiment, as shown in FIG. 12, the shared data X is updated (the determination in step 100 is affirmative), and the number of transmissions i of the shared data X is initialized ( Step 102) After acquiring the identifier of the shared data X (Step 106) and generating the digest of the shared data X (Step 106), in the next Step 107, they are stored in the P2P infrastructure management data storage unit 18. By referring to the information, the peer group A sharing the shared data X is recognized. Peer group A has a sub-peer group a included in peer group A (see FIG. 11A) and a sub-peer group a does not exist (FIG. 7A). See). In the next step 109, information obtained by adding the group identification information (corresponding to the identification information described in claim 4 ) indicating the peer group recognized in step 107 to the identifier x, the digest, and the transmission source information (the ID of the own peer). Is generated and stored in the application memory 22.

  In the next step 136, it is determined whether or not the peer group A recognized in step 107 includes the sub-peer group a included in the peer group A. If the determination is negative, the process proceeds to step 138, and all peers belonging to peer group A (peers other than the own peer) are recognized as transmission targets in the same manner as step 110 described in the first embodiment. On the other hand, if the determination in step 136 is affirmative, the process proceeds to step 140, and all of the sub-peer groups a included in the peer group A are based on the information stored in the P2P infrastructure management data storage unit 18. A peer (a peer other than its own peer belonging to peer group A and sub peer group a) is recognized as a transmission target. Note that in the shared data distribution process according to the second embodiment, steps other than those described above are the same as the shared data distribution process according to the first embodiment, and a description thereof will be omitted.

  By the above processing, for example, as shown in FIG. 11A, the shared data updated by the peer 2 is shared within the peer group A (each peer held by the peer group A holds). If there is a sub-peer group a included in the peer group A, as shown in FIG. 11B as an example, the peer 2 belongs to the peer group A and belongs to the sub-peer group a. The update notification information is transmitted only to the peer 1 and the peer 3 to which they belong.

  Next, shared data synchronization processing according to the second embodiment will be described. In the shared data synchronization processing according to the second embodiment, as shown in FIG. 13, when update notification information is received (determination in step 150 is affirmative), the process proceeds to step 167, and group identification information and Source information is extracted. In step 168, based on the group identification information and the transmission source information extracted in step 167, the shared data X notified of the update is data updated by a peer belonging to the sub-peer group a and belonging to the peer group A. By determining whether or not the data is shared by the peer group A, it is determined whether or not the data should be relayed to each peer belonging to the peer group A and not belonging to the sub-peer group a.

  Further, when the shared data X notified of the update by the received update notification information is data that is not stored in the non-volatile storage means of the own peer (determination in step 154 is negative), or the non-volatile of the own peer If the shared data X already stored in the storage means is the data before update (determination in step 159 is negative), acquisition for requesting acquisition of the shared data X is performed as in the first embodiment. The request information is generated (step 160), and the acquisition request information of the generated shared data X is stored in the application memory 22 in association with the transmission source information extracted from the update notification (step 163). When it is determined that the shared data X notified of the update in the previous step 168 is the data to be relayed, in this step 163, the shared data The acquisition request information X in association with the transmission source information and the relay identification information is stored in the application memory 22.

  In the shared data synchronization processing according to the second embodiment, if the determination in steps 150 and 170 is negative, the process proceeds to step 178, where it is determined whether the current activation factor is reception of shared data. When the determination in step 178 is affirmed by receiving the shared data X from the notification information transmission source peer, the received shared data X is stored in the non-volatile storage means of the own peer (steps 180 to 184). Then, it is determined whether or not the shared data X acquisition request information stored in the application memory 22 in the previous step 163 is associated with the relay identification information, that is, whether or not the shared data X is data to be relayed. If the determination is negative, the process ends without performing any processing. If the determination is affirmative, the process proceeds to step 188, and the identifier of the shared data X extracted from the update notification information received in the previous step 152 x, the update notification information of the shared data X including the digest of the shared data X extracted from the update notification information in the previous step 158 and the transmission source information (own peer ID) is generated and temporarily stored in the application memory 22.

In step 190, all peers belonging to the peer group A and not belonging to the sub-peer group a are recognized based on the information stored in the P2P infrastructure management data storage unit 18. In step 192, the update notification information of the shared data X is transmitted to all peers recognized in step 190. Thus, as shown in FIGS. 11C and 11D as an example, the latest from the peer (peer 2 in the figure) belonging to each of the peer group A and the sub-peer group a and in which the update of the shared data X has occurred. An update notification of shared data X is distributed to all peers (peer 4 to peer 6) belonging to peer group A and not belonging to sub-peer group a by the peer from which shared data X is acquired (peer 3 in the figure). Will be. Steps 188～ step 192 described above (more details second notifying means according to claim 4) second notification means according to claim 3 corresponds to.

  Further, in the shared data synchronization processing according to the first embodiment, although the update of the shared data X is notified from other peers by the update notification information, the latest shared data X is already stored in the non-volatile storage means of the own peer. In the shared data synchronization processing according to the second embodiment, the determination in step 159 is affirmative. However, in the shared data synchronization processing according to the second embodiment, the processing ends without performing any processing. If YES in step 169, the flow advances to step 169 to determine whether the shared data X is data to be relayed based on the recognition result in step 168. If the determination is negative, the process ends without performing any processing. If the determination is affirmative, the process proceeds to step 188. In steps 188 to 192, the process belongs to the peer group A and the sub-peer group. The update notification information is retransmitted to each peer not belonging to a. Even if communication with some of the peers belonging to the peer group A and not belonging to the sub-peer group a is temporarily interrupted by the retransmission of the update notification information, the shared data X It is possible to surely notify the some peers of the update.

In the shared data synchronization process according to the second embodiment, when the acquisition request information of the shared data X is received from the peer that has transmitted the update notification information, the determination in step 178 is denied and the process proceeds to step 194, where shared data distribution is performed. Similar to steps 130 to 134 of the process (FIGS. 8 and 12), the identifier x is extracted from the received acquisition request information to recognize the acquisition target shared data X (step 194), and the recognized shared data X ( (Updated data) is read from the non-volatile storage means of the own peer (step 196), and the read shared data X is transmitted to the acquisition request transmission source peer together with the identifier x (step 198). As a result, the shared data X stored in the nonvolatile storage means of the acquisition request information transmission source peer (peer belonging to peer group A and not belonging to sub-peer group a) is also synchronized ( (See also FIGS. 11E and 11F). Steps 194 to 198 described above correspond to the second transmission means described in claim 3 .

  In the second embodiment described above, each peer that has received the update notification information from the peer that has been updated to the shared data and belongs to the sub-peer group a belongs to the peer group A and does not belong to the sub-peer group a. Although an example in which update notification information is transmitted to each peer has been described as an example (for example, in FIG. 11D, peer 3 transmits update notification information to each peer, and in FIG. 11E, peer 1 transmits each peer. This is not limited to this, and there are a plurality of peers that belong to the sub-peer group a and have received update notification information from peers that have updated shared data. If it exists, the peers belonging to the peer group A and not belonging to the sub-peer group a are divided into a plurality of groups, and the update notification information is sent from the peer belonging to the sub-peer group a and the update of the shared data has occurred. Each peer that has received the information may transmit update notification information only to peers in different groups.

  In the above description, the digest (hash value) of shared data has been described as an example of information that can be used to determine whether the shared data stored in the non-volatile storage means of each peer is data before update. The peer that has updated the shared data transmits information including the update date / time of the shared data or the version of the updated shared data as update notification information, and the peer that has received the shared data The update date / time or version number notified together with the received shared data is stored, and every time update notification information is received, the update date / time or version number included in the received update notification information is stored together with the shared data. Alternatively, by comparing with the version number, it may be determined whether the already stored shared data is data before update.

It is a network block diagram of a P2P network. It is a network block diagram of pure P2P. It is a network block diagram of hybrid P2P. It is a conceptual diagram for demonstrating the group of a P2P network. It is a block diagram of the basic composition of a peer. It is a block diagram of a message control part. It is an image figure which shows an example of the transmission / reception sequence of the information between each peer in the synchronization of the shared data which concerns on 1st Embodiment. It is a flowchart which shows the content of the shared data delivery process which concerns on 1st Embodiment. It is a diagram which shows an example of the relationship between the frequency | count of transmission of an update notification, and a transmission interval. It is a flowchart which shows the content of the shared data synchronous process which concerns on 1st Embodiment. It is an image figure which shows an example of the transmission / reception sequence of the information between each peer in the synchronization of the shared data which concerns on 2nd Embodiment. It is a flowchart which shows the content of the shared data delivery process which concerns on 2nd Embodiment. It is a flowchart which shows the content of the shared data synchronous process which concerns on 2nd Embodiment.

Explanation of symbols

10 P2P network 12 Peer 18 Infrastructure management data storage unit 20 Application execution unit 22 Application memory

Claims (7)

An information processing apparatus connected via a communication line to a plurality of other information processing apparatuses belonging to the same first group as the own apparatus,
Storage means capable of storing shared data that each information processing device belonging to the first group should hold and synchronize with each other;
When the notification information for notifying that the shared data held by the specific information processing apparatus is updated is received from the specific information processing apparatus belonging to the first group, the waiting time determined at random An acquisition request means for transmitting an acquisition request for the shared data to the specific information processing apparatus after elapses;
Receiving means for receiving the shared data transmitted from the specific information processing apparatus based on the acquisition request transmitted by the acquisition request means, and storing the received shared data in the storage means;
An information processing apparatus including: From the specific information processing apparatus, as the notification information, each information processing apparatus that has received the notification information determines whether the shared data held by the individual information processing apparatus is pre-update data. Possible information is sent repeatedly at arbitrary time intervals,
The acquisition request unit determines that the shared data stored in the storage unit is pre-update data when the shared data is not stored in the storage unit and based on the received notification information. The acquisition request is transmitted to the specific information processing apparatus, and the acquisition request is not transmitted when it is determined that the shared data stored in the storage unit is updated data. The information processing apparatus according to claim 1. The information processing apparatus belongs to a second group including the first group, and is connected to a plurality of other information processing apparatuses not belonging to the first group and belonging to the second group via a communication line. Has been
After the receiving means receives from the specific information processing apparatus and stores in the storage means shared data that each information processing apparatus belonging to the second group should hold and synchronize with each other, the shared data Second notification means for transmitting notification information notifying that the information has been updated to all other information processing apparatuses not belonging to the first group but belonging to the second group;
Each time the second notification unit receives the shared data acquisition request from the information processing device that has transmitted the notification information, the shared data stored in the storage unit is sent to the acquisition request transmission source information processing device. A second transmitting means for transmitting;
The information processing apparatus according to claim 1, further comprising: If the shared data updated by the specific information processing apparatus is data that each information processing apparatus belonging to the second group should hold and synchronize with each other, it is transmitted from the specific information processing apparatus. Identification information indicating that the shared data is data that each information processing apparatus belonging to the second group should hold and synchronize with each other,
The second notifying unit does not belong to the first group and does not belong to the first group only when the identification information is added to the notification information received from the specific information processing apparatus. Send notification information to the device
The information processing apparatus according to claim 3. An information processing system in which a plurality of information processing devices belonging to the same first group are connected via a communication line,
Each of the plurality of information processing devices
Storage means capable of storing shared data that each information processing device belonging to the first group should hold and synchronize with each other;
When the shared data stored in the storage means is updated, notification information notifying that the shared data has been updated is transmitted to all other information processing devices belonging to the first group. 1 notification means;
Each time the first notification means receives the shared data acquisition request from the information processing apparatus that has transmitted the notification information, the shared data stored in the storage means is sent to the acquisition request transmission source information processing apparatus. First transmitting means for transmitting;
When the notification information for notifying that the shared data held by the specific information processing apparatus is updated is received from the specific information processing apparatus belonging to the first group, the waiting time determined at random An acquisition request means for transmitting an acquisition request for the shared data to the specific information processing apparatus after elapses;
Receiving means for receiving the shared data transmitted from the specific information processing apparatus based on the acquisition request transmitted by the acquisition request means, and storing the received shared data in the storage means;
An information processing system comprising: A plurality of information processing devices belonging to the same first group are connected via a communication line, and the plurality of information processing devices should be held by each information processing device belonging to the first group, and In an information processing system provided with storage means capable of storing shared data to be synchronized with each other,
When the shared data stored in the storage unit of the specific information processing apparatus is updated, the specific information processing apparatus receives notification information for notifying that the shared data has been updated. Send to all other information processing devices belonging to the group,
Each information processing device that has received the notification information from the specific information processing device transmits the shared data acquisition request to the specific information processing device after a randomly determined standby time has elapsed,
The specific information processing apparatus receives the shared data acquisition request from the information processing apparatus that has transmitted the notification information, and stores the shared data stored in the storage unit of the specific information processing apparatus. Send to the information processing device of the acquisition request transmission source,
Each data processing device that has transmitted the acquisition request receives the shared data transmitted from the specific information processing device based on the acquisition request, and stores the received shared data in the storage unit Method. Shared data that is connected via a communication line to a plurality of other information processing devices belonging to the same first group as the own device, and that each information processing device belonging to the first group should hold and synchronize with each other A computer having storage means capable of storing
When the shared data stored in the storage means is updated, notification information notifying that the shared data has been updated is transmitted to all other information processing devices belonging to the first group. 1 notification means,
Each time the first notification means receives the shared data acquisition request from the information processing apparatus that has transmitted the notification information, the shared data stored in the storage means is sent to the acquisition request transmission source information processing apparatus. First transmitting means for transmitting,
When the notification information for notifying that the shared data held by the specific information processing apparatus is updated is received from the specific information processing apparatus belonging to the first group, the waiting time determined at random An acquisition request means for transmitting an acquisition request for the shared data to the specific information processing apparatus after elapses;
And receiving means for receiving the shared data transmitted from the specific information processing apparatus based on the acquisition request transmitted by the acquisition requesting means and storing the received shared data in the storage means
Data synchronization program to function as.

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