JP3643574B2 - Process migration method, communication system, computer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a process migration method employed in a computer system that provides a service to a user of a mobile terminal.
[0002]
[Prior art]
With the spread of wireless technologies such as wireless LAN and Bluetooth (R), in addition to using fixed computers in offices and homes, access to the network using mobile terminals such as laptop computers and PDAs on the go Became easier.
[0003]
A user of a mobile terminal wants to be able to receive services obtained using an office or home computer in the same manner. However, since the processing capability of mobile terminals is poor compared to the processing capability of office and home computers, the services that can be provided are limited. Therefore, a method of receiving a service using resources (CPU processing capacity, memory, hard disk, etc.) possessed by a computer server existing on the network is taken.
[0004]
Since the mobile terminal communicates with the computer server via the base station and receives a service, the base station currently used by the mobile terminal is close to the computer server, that is, the base station and the computer server If there are fewer devices that relay and forward packets such as other computers and communication control devices (routers, hubs, bridges) that exist between the servers, the response from the computer server will be improved and resources will be saved (especially communication bandwidth will be saved). ), Desirable in terms of load distribution.
[0005]
However, the mobile terminal communicates with the computer server while appropriately switching the base station used for communication as the user moves. Therefore, even if the base station and the computer server are close to each other in a network at a certain time, the base station and the computer server are networked at another time when the mobile terminal has moved and the base station used for communication has changed. It often happens that it becomes far away.
[0006]
If the base station and the computer server are distant from each other in the network, the response from the computer server will deteriorate, or the communication bandwidth that can be used by other computers, communication control devices, etc. existing between the computer server and the base station will be consumed. Or a load concentrates on a specific computer server.
[0007]
In order to solve the above problem, a process operating on a computer server to realize a service may be moved from a base station used for communication by a mobile terminal to another computer server close to the network.
[0008]
There is a technique called “process migration” as a technique for moving a process between computers. Process migration is a process that replicates all data including code in the address space used by the process, the CPU register value, and the process execution status such as file information that the process has opened. The process is transferred to a destination computer, and a process having the same state as the above process state is generated and executed in the process destination computer.
[0009]
A technique for moving a process being executed to a place where a mobile terminal has moved is disclosed in Patent Document 1 and Non-Patent Document 1, for example.
[0010]
According to the technique disclosed in Patent Document 1, the movement of the process is started after confirming that the mobile terminal has moved.
[0011]
However, since the process movement requires a certain amount of time, when the process movement is completed, the mobile terminal may have already moved to another location.
[0012]
In this case, the location of the service providing process and the mobile terminal receiving the service remain separated from each other. Therefore, such as the delay in providing the service, the consumption of the communication band, and the load bias on the specific computer The problem cannot be solved sufficiently.
[0013]
The technique disclosed in Non-Patent Document 1 is called “PreCopy method” in process migration.
[0014]
In the PreCopy method, the entire contents of the address space are transferred in advance with the process being executed, the process is finally stopped, and the contents of the address space that have been changed after the previous transfer and other processes It is a technology for transferring state.
[0015]
However, in the PreCopy method, it is necessary to determine a computer that transfers a process before the start of process migration, and a transfer destination computer such as a response to a case where a mobile terminal moves unexpectedly during execution of process migration. It is not considered to change flexibly.
[0016]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-107577
[0017]
[Non-Patent Document 1]
M.M. Theimer, K .; Lantz, D.A. Cheriton. “Preemptable and remote execution facilities for the V-system.” In 10th ACM Symposium on Operating Systems Principles, pages 2-12, 1985
[0018]
[Problems to be solved by the invention]
In order to solve the problems arising from the distance between the mobile terminal and the process of providing services to the mobile terminal moving as described above, There is a way to move the process to a position.
[0019]
However, if the process is moved after confirming that the mobile terminal has moved, there is a problem that the mobile terminal moves to another location during the movement of the process.
[0020]
The present invention has been made in view of the above points, and realizes process migration corresponding to movement of a mobile terminal accurately and flexibly, so that the mobile terminal and the computer executing the process are separated from each other in a network. The purpose is to improve the service delay to the mobile terminal caused by being present.
[0021]
[Means for Solving the Problems]
In order to solve the above problems, a process migration method of the present invention includes a plurality of computers commonly connected via a network, a plurality of radio base stations connected to the network, and the radio base station via the radio base station. In a communication system having a mobile terminal connectable to a network, one of the plurality of computers executes a process that the mobile terminal causes a first computer that is one of the plurality of computers to execute. A process migration method for moving to another computer, wherein the first computer predicts a destination of the mobile terminal and includes the predicted destination in a wireless communication range. To another computer that is closer to the network distance from the destination radio base station than the network distance from the first computer to the first computer. Moving the processes running on the first computer.
[0022]
The process migration method of the present invention includes a plurality of radio base stations connected via a network, a plurality of computers connected via the network, and a mobile body connectable to the network via the radio base station. In a communication system having a terminal, a process that the mobile terminal causes a first computer that is one of the plurality of computers to execute the process is executed by another computer that is one of the plurality of computers. A process migration method for moving, a mobile terminal destination prediction step for predicting a destination of the mobile terminal, and a destination predicted by the mobile terminal destination prediction step as a wireless communication range The destination wireless base is more than the network distance from the destination wireless base station included therein to the first computer executing the process. A process movement destination search step for searching for the presence of a second computer that is close to the network from the station, and a second computer in the process movement destination search step when the first computer exists. A process movement step of moving an executing process to the second computer, and a determination of whether or not the mobile terminal is moving toward the destination predicted in the mobile terminal destination prediction step And when the mobile terminal is determined to have moved to a location different from the destination predicted in the mobile terminal destination prediction step in the determination step and the determination step, the process of the process movement step is performed. And a cancel step for canceling.
[0023]
Further, the process moving step is executed by generating a copy of the movement target process in the first computer, generating an execution record of the movement target process in the first computer, and executing from the first computer to the second computer. The first step of restoring the migration target process based on the copy in the second computer, and stopping the operation of the migration target process being executed in the first computer, The execution record generated from the start of the execution of the first procedure until the stop of the migration target process is transmitted from the first computer to the second computer, and the second computer based on the execution record A second stage procedure for reproducing the operation of the process to be moved.
[0024]
In addition, in the mobile terminal destination prediction step, a prediction confirmation destination is predicted in addition to the prediction of the destination, and in the process movement step, it is determined that the mobile terminal has reached the prediction confirmation destination in the determination step. Then, the execution of the procedure of the second stage may be started.
[0025]
In the stop step, when it is determined in the determination step that the mobile terminal has moved to a location different from the destination predicted in the mobile terminal destination prediction step, the process movement step If the state is after the start of the execution of the first procedure and before the start of the execution of the second procedure, the process of the process movement step is stopped and the mobile terminal movement destination prediction step is executed again. It may be characterized by.
[0026]
In the stop step, when it is determined in the determination step that the mobile terminal is moving to a location different from the prediction, after the start of execution of the first procedure in the process movement step, If the process movement step is in a state before the start of the execution of the second procedure, the process movement step is stopped, the movement destination prediction step is executed again, and the second process movement step is executed. If the state is after the execution of the procedure, the process moving step may be completed.
[0027]
In the stop step, when it is determined in the determination step that the mobile terminal is moving to a location different from the prediction, after the start of execution of the first procedure in the process movement step, If the process movement step is in a state before the start of the execution of the second procedure, the process movement step is stopped, the movement destination prediction step is executed again, and the second process movement step is executed. If it is in the state after the start of the execution of the procedure, the process movement process may be stopped, the movement target process may be operated again in the first computer, and the movement destination prediction step may be executed again. .
[0028]
The communication system of the present invention includes a plurality of computers commonly connected via a network and a plurality of radio base stations connected to the network, and each of the plurality of computers includes the radio base station. A destination prediction unit that predicts a destination of a mobile terminal connected to the network via the network, and a destination wireless base station that includes the destination predicted by the destination prediction unit in a wireless communication range. A process migration processing unit configured to move a process being executed to another computer having a network distance closer to the destination wireless base station than a network distance to the middle computer.
[0029]
The computer according to the present invention includes a communication unit that communicates with another computer via a network, and a destination that predicts a destination of a mobile terminal connected to the network via a radio base station connected to the network. More than the network-like distance from the destination wireless base station that includes the destination predicted by the destination prediction unit in the wireless communication range to the computer that is currently executing the process, from the destination wireless base station A process migration processing unit for moving a process being executed to another computer having a short network distance;
[0030]
The computer according to the present invention includes a communication unit that communicates with another computer via a network, and a location monitoring unit that monitors the location of a mobile terminal connected to the network via a radio base station connected to the network. A destination prediction unit that predicts a destination of the mobile terminal, and a network-like distance from the destination wireless base station that includes the destination predicted by the destination prediction unit within a wireless communicable range to the local computer Rather than a process destination search unit that searches for a first computer that is closer to the network from the destination radio base station, and a copy of the process that is being executed is generated, and the process destination search unit searches for this. The process transmitter that transmits to the first computer and the current position of the mobile terminal are acquired from the location monitoring means, and the mobile terminal is different from the prediction of the destination prediction unit If it is determined to be moving towards the location includes a controller for stopping the processing of the process transmitter unit.
[0031]
The computer of the present invention performs a process in response to a request from a mobile terminal connected to the network via a communication means that communicates with another computer via the network and a radio base station connected to the network. A process execution means for executing, a location monitoring means for monitoring the location of the mobile terminal, a destination prediction unit for predicting a destination and a prediction confirmation destination of the mobile terminal, and a movement predicted by the destination prediction unit Process destination search for searching for a first computer that is closer to the network distance from the destination wireless base station than the network distance from the destination wireless base station to the local computer including the destination within the wireless communication range A first process migration transmission processing unit for generating a copy of the running process and transmitting it to the first computer, and the location monitoring means. A second process migration transmission processing unit that stops the process being executed after it is determined that the mobile terminal has reached the prediction confirmation destination, and transmits a difference from the copy to the first computer; If the current position of the mobile terminal is acquired from the monitoring means and it is determined that the mobile terminal is moving toward a position different from the prediction, the mobile terminal predicts the mobile destination again. In addition, when the process destination search unit is made to search for the destination computer again, the first process migration transmission processing unit is made to perform the process again, and the mobile terminal has reached the prediction confirmation destination Includes a control unit that causes the second process migration transmission processing unit to perform processing.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
(First Embodiment) The first embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are block diagrams showing the configuration of a communication system according to the first embodiment of the present invention.
[0033]
FIG. 1 shows a mobile terminal used by a user, radio base stations A, B, C, D, E, and F that perform radio communication with the mobile terminal, and a computer that executes a process in response to a request from the mobile terminal A, B, C, D, E, F, a network connecting each wireless base station and each computer, and communication control devices A, B, C, D, E for transferring communication data on the network to appropriate destinations , F.
[0034]
Computers A, B, C, D, E, and F are so-called PCs (personal computers) and WSs (workstations), and are computers having a CPU (central processing unit), memory, HDD (hard disk drive), and the like. In other words, they are commonly connected via a network and can communicate with each other.
[0035]
The wireless base stations A, B, C, D, E, and F are like wireless LAN access points, for example. This may be changed as appropriate according to the scale of the communication system, and in some cases, a base station such as a mobile phone may be used.
[0036]
Examples of the communication control devices A, B, C, D, E, and F include a switching hub, a router, or a computer having these functions. Further, in the drawing, only one mobile terminal is shown for the sake of simplicity of explanation, but a plurality of mobile terminals may actually exist.
[0037]
Here, computer A, wireless base station A, communication control device A, computer B, wireless base station B, communication control device B, computer C, wireless base station C, communication control device C, computer D, wireless base station D, The communication control device D, the computer E, the radio base station E, the communication control device E, the computer F, the radio base station F, and the communication control device F are all present at points A, B, C, D, E, and F, respectively.
[0038]
For example, when the mobile terminal at the point A executes the process with the computer A on the network, it is as follows.
[0039]
The mobile terminal at point A is connected to the nearest radio base station A. Then, the mobile terminal accesses the computer A on the network via the radio base station A and the communication control device A and requests a service. Computer A starts executing the process in response to the request. In this way, the mobile terminal can use the computer resources on the network and receive services equivalent to those used when using office or home computers.
[0040]
In FIG. 1, when a mobile terminal communicating with the computer A at point A moves to point D, the radio base station D-> communication control device D-> communication control device C-> communication control device B-> communication Communication is performed through a route of control device A-> computer A.
[0041]
However, if the process is executed by the computer A as it is and services are provided to the mobile terminal, network resources are wasted because communication is performed via a plurality of communication control devices (including a computer depending on the system configuration). In addition, when there is a computer installed by a malicious person on the network in the middle, there is a problem in terms of security, such as intercepting communication contents between the mobile terminal and computer A or tampering with communication data. is there.
[0042]
Therefore, in the communication system according to the present embodiment, the computer A that provides a service to the mobile terminal predicts the destination of the mobile terminal, and for example, predicts that the mobile terminal is moving toward the point D. Is to start moving the process being executed on the computer A to the computer D before the mobile terminal reaches the point D, thereby saving network resources and improving the response of the process.
[0043]
In the communication system according to the present embodiment, the wireless base station and the computer have a one-to-one correspondence. However, the correspondence may be changed as appropriate depending on the situation. For example, if the number of services required by a mobile terminal is large, install multiple computers in one radio base station and distribute the load of the computers (priority over the round robin method and low load computers) When a service is provided to mobile terminals distributed over a wide range compared to the communication range of the radio base station, the output is output in a building, for example. In the case of providing a service by installing a large number of weak radio base stations, it may be possible to install a plurality of radio base stations corresponding to one computer.
[0044]
(Outline of Process Migration Process) The process migration process in the communication system of this embodiment is roughly divided into two stages. Here, the outline will be described by taking as an example the case where the process being executed on the computer A is moved to the computer B which is the movement prediction destination.
[0045]
In the first stage, the computer A generates a copy of the process while executing the process to be moved. That is, all data in the address space used by the process is read and a copy thereof is generated. Then, computer A transmits a copy of the address space data to computer B, which is the movement prediction destination. The computer B receives this and restores the process in the address space of the computer B.
[0046]
In the second stage, the execution of the migration target process is stopped in the computer A, the data in the address space that has been changed since the end of the first stage, the value of the CPU register, and the open file Information or the like is transmitted to computer B. The computer B receives these and reproduces the state at the time of the process stop.
[0047]
Since the first stage is performed with the migration target process being executed, the process migration process is performed when, for example, after the completion of the first stage, the prediction is lost as it is found that the movement prediction destination is not the computer B but the computer D. Canceling and starting over does not affect the process to be moved. That is, if the first stage is in the state at the end, the process destination can be changed at any time.
[0048]
In the second stage, only the contents that have changed since the end of the first stage are transmitted among the data in the address space, so that the amount of data is small compared to the first stage, and high-speed processing is possible. As a result, even if the second stage of processing is performed in accordance with the timing at which the mobile terminal moves, the process can be completed before the mobile terminal arrives, or the process can be completed without delay after the mobile terminal arrives. It can also be made. That is, the process can be moved at an arbitrary timing.
[0049]
(Details of communication system)
FIG. 2 is a diagram in which portions A and B in FIG. 1 are extracted for detailed description of the communication system of the present embodiment.
[0050]
As in FIG. 1, the computers A and B, the communication control devices A and B, and the radio base stations A and B are connected by a network. Then, the mobile terminal communicates with the computers A and B using the radio base station A or B nearest from the current location and receives a service.
[0051]
The radio base stations A and B add their own identification information to the communication data from the mobile terminals connected to the radio base stations A and B and transfer them to the target computer. For example, if the mobile terminal is communicating with the computer A via the radio base station B, the radio base station B uses “the radio base station B for communication data transmitted from the mobile terminal to the computer A. Is added to the computer A and transferred to the computer A. This information is used by computer A to grasp the current location of the mobile terminal.
[0052]
The communication control devices A and B in the middle of the network transfer the communication data toward an appropriate destination.
[0053]
The computers A and B have process management mechanisms A and B, user movement prediction units A and B, and process migration processing units A and B, respectively. In the present embodiment, it is assumed that these are implemented as one function of an OS (operating system) kernel that runs on the computers A and B. These may be implemented as one process.
[0054]
The process management mechanism receives a request from the mobile terminal via the radio base station. Then, process generation / execution and data transfer to the process are performed, and an output result of the process is received and transferred to the mobile terminal via the radio base station. Also, identification information of the radio base station used by the mobile terminal is extracted and notified to the user movement prediction unit.
[0055]
As shown in FIG. 3, the user movement prediction unit is configured to show the positions of all the radio base stations in the system (coordinates with a certain point as a reference point) and the nearest computer in terms of network from each radio base station. Have a map. Using this system configuration map information and the location information of the mobile terminal estimated from the identification information of the radio base station given from the above-mentioned process management mechanism, the movement path of the mobile terminal is predicted, and a process is performed based on the prediction. The migration processing unit is notified to start the process of the first stage of process migration.
[0056]
After the start of the first stage of processing, it is verified whether the movement route is predicted correctly. When it is determined that the prediction is correct, the process migration processing unit is notified to perform the second stage process of the process migration. On the other hand, if the prediction is incorrect, the movement route is predicted again.
[0057]
The process migration processing unit starts the process of the first stage and the second stage of the process migration according to an instruction from the user movement prediction unit. Further, the time required for the process migration process is estimated in response to a request from the user movement prediction unit.
[0058]
In the first stage process when a process moves from computer A to computer B, the process migration processing unit A transmits address space data to the process migration processing unit B. Then, the process migration processing unit B restores the process to the address space of the computer B based on the received data.
[0059]
The same applies to the processing in the second stage, and the process migration processing unit B reflects the information transmitted by the process migration processing unit A in the process on the computer B.
[0060]
The time required for the process migration process is estimated using, for example, the amount of information (all data in the process address space as described above) transmitted during the first stage of process migration and the communication speed to the destination computer.
The mobile terminal has a process management table as shown in FIG. 4 in order to manage which process of which computer corresponds to the requested service.
[0061]
In the process ID item, an identification ID of a process executed by a computer on the network in response to a request from a mobile terminal is registered, and in the computer ID item, an identification ID of a computer executing a corresponding process is registered. be registered. An IP address fixed to the computer may be used as the computer identification ID.
[0062]
In the present embodiment, the server side system of the communication system is configured to include computers A, B,..., Radio base stations A, B, .. and communication control devices A, B,. However, as shown in FIG. 5, instead of the wireless base stations A, B,..., The wireless ports A, B,. In this case, the mobile terminal communicates with the computers A, B... Via the wireless port unit.
[0063]
(Process Activation) In the present embodiment, the flow of processing in the case where the mobile terminal at the point A in FIG. 1 requests a service from the computer A and the computer A starts a process in response thereto will be shown.
[0064]
(1) A mobile terminal at point A is connected to a radio base station A using a radio interface.
(2) The mobile terminal requests a service from the mobile terminal to the computer A.
(3) The radio base station A adds an ID unique to the radio base station A to the service request from the mobile terminal to the computer A, and transfers it to the process management mechanism of the computer A.
[0065]
(4) The process management mechanism of computer A creates a process for executing the requested service, and attaches a process ID unique within the system.
(5) The process management mechanism of computer A notifies the user movement prediction unit of the base station ID and process ID pair.
(6) The user movement prediction unit prepares for the movement of the mobile terminal by performing the process of FIG.
[0066]
(7) The process management mechanism of computer A starts execution of the process and transmits the process ID to the mobile terminal that requested the service.
(8) The mobile terminal registers the identification ID of the computer A and the process ID transmitted from the computer A together in the process management table.
[0067]
In the above process (4), when the process ID set by the process management mechanism is set to a value (unique value in the system) such as “ID of mobile terminal” + N (positive integer value), for example, The mobile terminal ID that is the request source of the process can be easily determined from the process ID.
[0068]
(Outline of Processing of Entire Communication System Accompanying Movement of Mobile Terminal) Next, in the present embodiment, after the mobile terminal at the point A in FIG. The flow of processing when moving to a point is shown.
[0069]
(1) The mobile terminal that has moved to the point B starts connection with the radio base station B.
(2) The mobile terminal refers to the process management table, acquires the ID of the computer (in this case, computer A) that is executing the process providing the service, and wirelessly sends a communication request to the process with the same computer as the destination. Send to base station B.
(3) The radio base station B adds the ID unique to the radio base station B to the request from the mobile terminal and transfers the request to the computer A.
[0070]
(4) The computer A transfers the received data to the process management mechanism A.
(5) The process management mechanism A passes the data received from the mobile terminal to the process providing the service, and notifies the user movement prediction unit of the set of the ID of the radio base station and the process ID.
(6) The user movement prediction unit performs a process corresponding to the movement of the mobile terminal by performing the process of FIG.
[0071]
(Outline of Operation of User Movement Prediction Unit) Next, an outline of operation of the user movement prediction unit will be described.
[0072]
Usually, since the location of the user and the location of the mobile terminal are the same, the prediction result of the destination of the user and the prediction result of the destination of the mobile terminal are the same. Therefore, the user movement prediction unit of the present embodiment performs movement destination prediction of the mobile terminal.
[0073]
The user movement prediction unit has a movement prediction map as shown in FIG.
[0074]
In the process ID item, the identification ID of the process providing the service is registered. In the initial point item, the ID of the radio base station used by the mobile terminal when the mobile terminal requested the service is registered. In the item of Time, the time when the mobile terminal that requested the service is registered in the movement prediction map is registered, and this is used when the user movement prediction unit calculates the movement speed of the mobile terminal later.
[0075]
In addition, in the item of the pointer to the predicted route map, when it is notified that the mobile terminal that requested the service has connected to another computer at the destination, a new predicted route map (to be described later) is created and stored in the memory. Register the address.
[0076]
In the predicted route map, the computer ID of the computer nearest to the network from the wireless base station on the route predicted by the user movement prediction unit, the migration flag corresponding to each computer, and the movement notification are sent to the user movement prediction unit. The arrival time of the mobile terminal is registered.
[0077]
There are three types of migration flags: Destination, Fix, and OK. These flags are not exclusive. For example, an OK flag and a Fix flag may be set at the same time. Hereinafter, the meaning of each flag will be described.
[0078]
(1) The Destination flag indicates that the computer closest to the network from the wireless base station is the destination of the process.
(2) The Fix flag is a radio base station that becomes a point that “when the mobile terminal reaches the place where the radio base station is used, the destination prediction is determined to be correct and the second stage of process migration is started” Indicates that
(3) The OK flag indicates that the mobile terminal has already reached the place where the radio base station is used (including the case where the mobile terminal has already passed).
[0079]
(Operation of User Movement Prediction Unit) The process flow of the user movement prediction unit will be described below with reference to FIGS.
[0080]
FIG. 6 shows a process flow of the user movement prediction unit when the process ID and the radio base station ID are notified from the process management mechanism.
[0081]
(S601) The process ID and the radio base station ID are notified from the process management mechanism.
(S602) It is checked whether the notified process ID is registered in the movement prediction map.
[0082]
(S603) If the notified process ID is not registered in the movement prediction map, the process ID, the radio base station ID, and the current time are registered in the movement prediction map, and the corresponding prediction path map pointer is NULL (prediction Represents that there is no route map). Then, the process of S605 is performed.
(S604) When the notified process ID is registered in the movement prediction map, the value of the predicted route map pointer corresponding to the notified process ID is checked.
[0083]
(S605) If the predicted route map pointer is NULL, the processing of FIG. 8 described later is performed to create a predicted route map.
(S606) If the predicted route map pointer is not NULL, the processing of FIG. 9 described later is performed to check whether the mobile terminal is moving according to the predicted route map.
[0084]
FIG. 8 shows processing for creating a predicted route map in the user movement prediction unit.
[0085]
(S801) The positions of the radio base station ID registered in the movement prediction map (here, A) and the notified radio base station ID (here, B) are respectively acquired from the system configuration map.
[0086]
(S802) The moving speed V of the mobile terminal from the radio base station A to the radio base station B _u Is obtained by the following method. First, the distance L from the radio base station A to the radio base station B using the positions of the radio base stations A and B acquired in S801. _AB Calculate The time T registered in the time of the movement prediction map _A And the current time (because it is within the communication range of the wireless base station B, _B The mobile terminal travel time T from the radio base station A to the radio base station B is used. _AB Calculate And V _u = L _AB ÷ T _AB Calculate
[0087]
(S803) Using the value acquired in S801, a certain direction of the radio base station B viewed from the radio base station A is calculated, and the moving direction of the mobile terminal is obtained.
[0088]
(S804) Time T required for process migration from the process migration processing unit _MIG To get. T _MIG As described above, is an estimated value using the amount of data transmitted in the process of the first stage of process migration and the communication speed to the destination computer.
[0089]
(S805) The destination of the process by the process migration is determined by predicting the destination of the mobile terminal. The destination is predicted by predicting the radio base station used at the destination.
[0090]
First, the position of the radio base station in the moving direction of the mobile terminal is acquired from the system configuration map. And relational expression L _x ÷ V _u > T _MIG Using XF, a radio base station is obtained whose closest computer is a computer capable of completing the process migration prior to the arrival of the mobile terminal. However, L _x Is a distance from the radio base station A to the radio base station X (X is a radio base station in the moving direction of the mobile terminal), and F is a coefficient for reflecting a factor affecting the process migration. This is an amount calculated based on the fluctuation of the data, the destination and the load state of the source computer.
[0091]
Among the wireless base stations thus determined, a wireless base station closest to the currently connected wireless base station is selected (here, wireless base station D), and this wireless base station D exists. Predict D point as the destination. In addition, the computer nearest to the wireless base station D (here, computer D) is determined as the process migration destination.
[0092]
(S806) When the mobile terminal reaches which point on the route leading to the point D predicted in S805, it is determined whether to start the second stage of the process migration (here, point C).
[0093]
(S807) A predicted route map is created based on the results of S805 and S806, and registered in the movement predicted map. In the movement prediction map, all points from the current point to the predicted point are registered in order of the route. At this time, the migration flag set in the predicted route map is as follows. A “Destination” flag is set for the point predicted as the destination in S805, that is, the D point. The “Fix” flag is set for the point determined in S806, that is, the point C.
[0094]
(S808) The process migration processing unit is notified of the result of S805, and the first stage of the process migration process is started.
[0095]
FIG. 9 shows processing for confirming whether the mobile terminal is moving according to the predicted route map.
[0096]
(S901) The points registered in the predicted route map are sequentially referred to, and the radio base station ID corresponding to each point is checked from the system configuration map.
(S902) Then, it is checked whether the wireless base station ID checked in S901 is the same as the wireless base station ID notified from the process management mechanism.
[0097]
(S903) If the same radio base station ID does not exist in S902, it is considered that the mobile terminal has moved against the predicted route, so the process of FIG. 8 is performed to redo the prediction.
(S904) On the other hand, if the same radio base station ID exists, the mobile terminal has moved according to the predicted route, so it is checked whether the Fix flag is set in the Migration flag.
[0098]
(S905) If the Fix flag is set, the process migration processing unit is notified to start the second stage process of the process migration. (S906) If the Fix flag is not set, an OK flag is set for the Migration flag.
[0099]
(Operation of Process Migration Processing Unit) FIG. 10 shows processing of the process migration processing unit.
[0100]
(S1001) Upon receipt of a process migration first stage process start notification from the user movement prediction unit, the process migration first stage process is started.
[0101]
(S1002) Then, it waits until it receives a notification of the start of the process migration second stage from the user movement prediction unit.
(S1003) The process migration second stage is started after receiving the notification of the start of the process migration second stage from the user movement prediction unit.
[0102]
(S1004) After the completion of the process migration second stage process, the user movement prediction unit is notified that the process migration process has been completed. Upon receiving this notification, the user movement prediction unit deletes the item of the process from the movement prediction map.
[0103]
(S1005) The process transfer destination computer is notified to the mobile terminal that is the request source of the process moved from the process transfer source computer. Upon receiving this notification, the mobile terminal updates the process management table. As a result, the mobile terminal can normally communicate with the process even after the process migration.
[0104]
The process migration processing unit creates and moves a copy of the address space by a method as shown in FIG. This corresponds to a method called “PreCopy”.
[0105]
The first stage of process migration is a process performed when a notification is received from the user movement prediction unit so as to start the process of the first stage of process migration.
[0106]
In the process of the first stage of the process migration, all the contents (a, b ′, c, d ′) of the process address space are read out and the process execution is continued, and sent to the process migration processing unit of the migration destination computer. To do. Then, the data (a, b ′, c, d ′) is restored on the address space in the process migration processing unit of the migration destination computer.
[0107]
As an example of a method for reading the contents of the address space of the process being executed, a method using procs (process file system) can be considered.
[0108]
The process migration second stage is a process performed when a notification is received from the user movement prediction unit to start the process migration second stage process.
[0109]
In the process of the second stage of process migration, the execution of the process is stopped. Then, only the contents changed after the end of the first stage process are transmitted to the process migration processing unit of the destination computer. For example, as shown in FIG. 11, when (a, b ′, c, d ′) at the start of the first stage execution becomes (a, b ′, c ′, d ′) at the start of the second stage, Since the content changed during the one-step execution is (c ′), this portion is transmitted to the destination computer.
[0110]
It is assumed that process states such as open file states other than the address space and CPU register values are transferred in the second stage of process migration.
[0111]
In the first stage of process migration, since the process to be transferred continues to be executed, even if the process migration is stopped and the process migration is performed again for another computer, there is no influence on the process being executed. Therefore, the process destination can be changed at any time before the start of the second stage of process migration.
[0112]
Further, since the address space transferred in the second stage of process migration is only the contents changed after being transferred in the first stage of process migration, the process of the second stage of process migration can be performed at high speed. Therefore, even after starting the second stage of process migration after it is determined that the prediction of the destination of the mobile terminal is correct, that is, after the mobile terminal has approached the prediction point to the extent that the Fix flag is set, The process can be moved in accordance with the timing at which the mobile terminal arrives at the predicted destination.
[0113]
There is a method for comparing the address space generated in the first stage and the address space at the time of the second stage execution as a method for obtaining the difference of the address space, but this method is suitable for a process using a large address space. Is difficult to apply.
[0114]
As another method, after the copy is generated in the first stage, the process is executed while monitoring the writing to the address space, and when the writing to the address space is detected, the contents or the address of the address space are recorded. In addition, when the difference is transmitted in the second stage, a method of generating difference information based on the recording can be considered.
[0115]
As described above, in this embodiment, the process migration process is performed by predicting the destination of the mobile terminal. However, the process migration process is performed in two stages, so that the current process migration process is performed even if the prediction is not satisfied. Can be dealt with by canceling the process, performing the prediction again, and performing the process migration process, so that the process movement accurately following the movement of the mobile terminal can be realized.
[0116]
As a result, it is possible to improve the problem of the deterioration of the response and the waste of the communication band caused when the mobile terminal and the computer executing the process are separated from each other in the network. Further, since the process moves fluidly with the movement of the mobile terminal, the concentration on a specific computer load can be reduced.
[0117]
In the present embodiment, the process migration first stage process is executed only once. However, the process migration first stage process may be performed a plurality of times before the process migration second stage process is performed.
[0118]
In other words, the contents of the address space used by the process are transmitted in the first process of the first time, and the contents changed from the previous process in the contents of the address space in the first process of the second and subsequent times. Only send. By performing the first stage processing a plurality of times in this way, the contents of the address space to be transmitted in the second stage of process migration can be reduced, and the processing time of the second stage of process migration can be shortened. As a result, there is an advantage that the process stop time can be shortened.
[0119]
In this embodiment, it is assumed that after the start of the second stage processing, it is not checked whether the destination prediction is correct. However, if necessary, for example, after the start of the second stage processing, the destination computer You may check with In this case, if the prediction is not correct, the prediction is performed again on the destination computer, and after the second stage process is completed and the process is completed, the process migration process is performed again on the destination computer. Just do it.
[0120]
Alternatively, the check may be performed by the source computer even after the start of the second stage processing. In this case, the migration source process pauses at the source computer at the start of the second stage of processing, and the second stage of processing is stopped when the prediction is lost, and the migration source computer pauses at the migration target process. The process is moved again (the migration destination process is discarded by the migration destination computer), and the process migration process is performed by performing the prediction again. In the case of moving as predicted, the process of the source computer is stopped at the end of the second stage.
[0121]
In the present embodiment, the determination of the destination computer of the process is based solely on the prediction of the destination of the mobile terminal, but in addition to this, the determination is based on the prediction of the destination of the mobile terminal. If the load state of the process move destination computer is checked and a load exceeding a predetermined load is applied, the process may be moved from the computer to another computer in the network. In this way, it can be expected that the load concentration can be further eased.
[0122]
(Second Embodiment) The second embodiment of the present invention will be described below with reference to the drawings.
[0123]
The system configuration of this embodiment is the same as that of the first embodiment, and is represented in FIG. 1 and FIG. Since most of the configuration is the same, only the differences will be described.
[0124]
(Process management mechanism) The process management mechanism of this embodiment receives a request from a mobile terminal via a radio base station, and generates and executes a process and transfers data to the process. Furthermore, the output result from the process is received and transferred to the mobile terminal. In addition, every time a request from the mobile terminal is received, the user movement prediction unit is notified of the IP address of the mobile terminal and the ID of the radio base station used by the mobile terminal.
[0125]
The process management mechanism has a mobile terminal management table as shown in FIG. The mobile terminal management table is used to manage the IP address of the mobile terminal, the communication port number on the computer side used when the mobile terminal communicates with the process operating on the computer, and the process ID. When the process management mechanism generates a process in response to a request from the mobile terminal, it registers these pieces of information in the mobile terminal management table.
[0126]
When executing the process migration process, the process management mechanism refers to the mobile terminal management table to the mobile terminal that has requested the execution of the moved process, the IP address and the transfer source of itself (the transfer source computer). The communication port number on the computer side, the IP address of the destination computer, and the communication port number on the destination computer side are notified.
[0127]
(User movement prediction unit) The user movement prediction unit predicts a user's movement path based on the information notified from the process management mechanism and the system configuration map described in the first embodiment, and passes the process management mechanism. To notify the process migration processing unit to start the first stage of the process migration.
[0128]
If the prediction is determined to be correct, the process migration processing unit is notified via the process management mechanism to start the process migration second stage process. On the other hand, if the prediction is incorrect, the prediction is redone, and the process migration processing unit is notified via the process management mechanism to start the first stage of process migration based on the new prediction. To do.
[0129]
(Process Migration Processing Unit) The process migration processing unit performs the process of the first stage and the second stage of the process migration according to an instruction from the user movement prediction unit.
[0130]
(Radio base station) The radio base station notifies the position of the mobile terminal to the computer with which the mobile terminal is communicating. Therefore, when a wireless base station transfers a request from a mobile terminal connected to itself to a computer, it reads out the IP address and communication port number of the destination computer from the transferred data and adds its own ID to this. Then, mobile terminal information is generated and notified to the destination computer.
[0131]
In addition, the radio base station stores the generated mobile terminal information and the notification destination thereof, and thereafter reduces the amount of communication by not transmitting the same mobile terminal information as the content stored in the same computer. Is possible.
[0132]
(Mobile Terminal) The mobile terminal of this embodiment has a process management table as shown in FIG. Using this process management table, the source port number, computer IP address and port number, new computer IP address and new destination port number, communication type, and descriptor are managed.
[0133]
The communication source port number is a communication port number on the mobile terminal side used for communication with the process being executed by the mobile terminal on the computer. The computer IP address and port number are the IP address of the computer that is executing the process and the communication port number on the computer side that the mobile terminal uses for communication with the process that is being executed by the computer.
[0134]
The new computer IP address and new destination port number are the IP address of the destination computer and the communication port number on the destination computer when the process is moved by the process migration process. The type of communication is information such as connection type communication or non-connection type communication. In this embodiment, TCP is used as an example of connection type communication and UDP is used as an example of non-connection type communication. As the descriptor, a descriptor representing a TCP communication path is registered, and in the case of UDP, a NULL value is registered.
[0135]
(Process Activation) An outline of the flow of processing when the mobile terminal at point A in FIG. 1 requests a service from the computer A and the computer A starts a process in response thereto will be shown below. Here, a description common to TCP and UDP will be given.
[0136]
(1) The mobile terminal at point A connects to the radio base station A using the radio interface.
(2) The mobile terminal requests a service from the mobile terminal to the computer A.
(3) The radio base station A receives the request (2) and transfers it to the computer A.
[0137]
(4) The process management mechanism of the computer A generates a process for executing the requested service, and attaches a process ID unique within the system. Further, a communication port used for communication between this process and the mobile terminal is generated. Then, the mobile terminal IP address, communication port number, and process ID are registered in the mobile terminal management table.
(5) The process management mechanism of computer A transmits the set of the communication port number and the IP address of computer A created in (4) to the mobile terminal that requested the service.
[0138]
(Communication between mobile terminal and process) Next, when the mobile terminal at point A in FIG. 1 requests a service from the computer A and starts the process, communication with this process is performed by UDP. The flow of processing will be described.
[0139]
(1) The mobile terminal at point A connects to the radio base station A using the radio interface.
(2) The user designates the port number transmitted from computer A at the start of the process and the IP address of computer A as the destination for the mobile terminal, and the computer A that is the destination for certain data (hereinafter, data X) Request to be sent to.
[0140]
(3) Upon receiving the request of (2), the mobile terminal searches the information registered in the process management table for information corresponding to the destination of the request and the type of communication. If not, register new.
(4) The mobile terminal refers to the process management table and transmits the data X after rewriting the destination if necessary. Specifically, when values are registered in the new destination port number and new computer IP address items, the destination specified in (2) is rewritten with the new port number and new computer IP address. If the new destination port number and new computer IP address are not registered, the destination is left as it is.
[0141]
(5) Upon receiving the data X, the wireless base station A reads the destination computer IP address and port number, and the IP address and port number of the source mobile terminal, and then transfers the data X to the destination computer. To do.
(6) The radio base station A generates mobile terminal information by adding the information of its radio base station ID to the information such as the IP address read in (5), and notifies the destination computer of the data X .
[0142]
(7) The process management mechanism of the destination computer receives the transferred data X and transfers this data X to the corresponding process.
(8) The process management mechanism of the destination computer receives the mobile terminal information generated in (6) and notifies the user movement prediction unit.
(9) The user movement prediction unit performs the process of FIG.
[0143]
Here, as described in (4), the destination IP address and the communication port are rewritten. This eliminates the need for the user to be aware of process movement.
[0144]
When the communication with the service is TCP, when the user establishes a connection with the process being executed on the computer A, the mobile terminal determines the port number of the communication source, the IP address and the port of the destination computer from the connection establishment request data. The number and the type of communication (TCP in this case) are read out. After the connection is established, the read information is registered in the process management table together with a descriptor indicating the communication.
[0145]
In the case of TCP communication, there is no need to rewrite the destination IP address and communication port as in the case of UDP, so the data X is transmitted without performing the process (4).
[0146]
Next, when the user of the mobile terminal at the point A in FIG. 1 requests the service at the computer A and starts the process and then moves to the point B while continuing the service, the communication with this process is set to UDP. The flow of processing when performing the above will be described.
[0147]
(1) The mobile terminal that has moved to the point B is connected to the radio base station B using the radio interface.
(2) to (4) are the above-mentioned cases (2) when the mobile terminal at the point A in FIG. 1 requests a service from the computer A and starts the process, and then communicates with this process by UDP. ) To (4). That is, the mobile terminal refers to the process management table and rewrites the destination if necessary.
[0148]
(5) Upon receiving the data X, the radio base station B reads the IP address and port number of the destination computer, the IP address and port number of the source mobile terminal, and then transfers the data X to the destination computer.
(6) The radio base station B generates mobile terminal information from the information read in (5) and its own radio base station ID, and notifies the destination computer.
(7) to (9) are the cases of the above-mentioned “when the mobile terminal at the point A in FIG. 1 requests a service from the computer A and starts the process, and then communicates with this process by UDP” (7 ) To (9) are performed.
[0149]
In addition, when communicating by TCP, it is the same as the above-mentioned "when the mobile terminal at the point A in FIG. 1 requests a service from the computer A and starts the process, and then communicates with this process by UDP". The mobile terminal acquires information on the IP address and port number when establishing a connection, and registers the information together with the descriptor in the process management table after establishing the connection. Further, the mobile terminal does not perform the process (4).
[0150]
(Operation of User Movement Prediction Unit) The user movement prediction unit has a movement prediction map as shown in FIG. In this movement prediction map, the process ID is registered in the first embodiment, but in this embodiment, the IP address of the mobile terminal is registered instead.
[0151]
The operation of the user movement prediction unit is the same as that of the first embodiment and is represented in FIGS. However, the part handling the process ID in FIG. 6 is different in that the IP address of the mobile terminal is handled.
[0152]
(Operation of process migration processing unit)
FIG. 15 shows the operation of the process migration processing unit. Details are as follows.
[0153]
(S1501) Upon receipt of a process migration first stage process start notification from the user movement prediction unit, the process migration first stage process is started.
(S1502) Then, the process waits until a notification of the start of the process migration second stage process is received from the user movement prediction unit.
(S1503) The process migration second stage is started after receiving notification of the start of the process migration second stage from the user movement prediction unit.
[0154]
(S1504) After the completion of the process migration second stage process, the user movement prediction unit is notified that the process migration process has been completed. Upon receiving this notification, the user movement prediction unit deletes the item of the mobile terminal from the movement prediction map.
(S1505) The IP address and port number of the process transfer destination computer and the IP address and port number of the process transfer source computer are notified from the process transfer source computer to the mobile terminal requesting the moved process. To do.
[0155]
(Operation of Mobile Terminal After Completion of Process Migration Process) The mobile terminal updates the process management table upon receiving the notification of S1505 from the process source computer.
[0156]
First, the mobile terminal searches the process management table to find an entry (old entry) in which the IP address and port number of the source computer are registered in the “computer IP address and port number” item.
[0157]
When communication with the moved process is performed by UDP, the IP address and port number of the destination computer are registered in the item “new computer IP address and new destination port number” of the old entry. This is the case for UDP.
[0158]
If communication with the moved process was performed using TCP, the source port number and descriptor information were extracted from the old entry, and the process moved to the item "Computer IP address and port number". The previous IP address and port number are registered, the source port number extracted from the old entry is registered in the “source port number” item, and the descriptor extracted from the old entry is registered in the “descriptor” item. A new entry (new entry) is generated.
[0159]
Then, the mobile terminal disconnects the TCP connection established with the source computer and deletes the old entry from the process management table. In addition, the new computer IP address and new port number are specified as the communication destination, the IP address of the user (mobile terminal) and the communication source port number extracted from the old entry are specified as the communication source, and a new Establish a connection.
[0160]
As a result, communication to the process after process migration can be performed using a new connection without the user being aware of it.
[0161]
(Third Embodiment) The third embodiment of the present invention will be described below. In the present embodiment, the operation of the process migration processing unit in the first and second embodiments is changed, and this portion will be mainly described.
[0162]
In the embodiments so far, the process migration process has a first stage and a second stage. In the first stage, the contents of the address space are copied and transferred, and in the second stage, the difference generated after the execution of the first stage is started. It was a method of transferring.
[0163]
In this embodiment, in the first stage, the contents of the address space are copied and transferred to the destination computer as in the previous embodiments. However, in the second stage, instead of obtaining the difference of the contents of the address space, the movement source computer records the operation of the movement target process after the start of the first stage execution and the result thereof to generate an execution record. Then, in the second stage, this execution record is transferred to the migration destination computer, and the process of the migration target process is reproduced based on the execution record in the process migration processing unit of the migration destination computer, thereby synchronizing the contents of the address space. Take.
[0164]
In this embodiment, it is assumed that the process migration realization unit of each computer performs execution record generation and reproduction processing.
[0165]
Since execution recording is used in this way, even when the address space is changed over a wide range (for example, decompression of compressed data or decompression of encoded data), compared with the case where the difference in address space is used. Process synchronization can be achieved with less information.
[0166]
【The invention's effect】
As described above, according to the present invention, it is possible to realize process movement that accurately follows movement of a mobile terminal, so that the mobile terminal and the computer that executes the process are separated from each other in a network. The service delay to the mobile terminal caused by the above can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a communication system according to a first embodiment of the present invention.
FIG. 2 is a detailed diagram of the configuration of the server system of the communication system in FIG.
FIG. 3 is a diagram illustrating the configuration of a system configuration map held by a user movement prediction unit.
FIG. 4 is a diagram for explaining the configuration of a process management table managed by a mobile terminal.
FIG. 5 is a diagram illustrating a configuration of a modification of the communication system according to the first embodiment of the present invention.
FIG. 6 is a diagram for explaining a flow of processing of a user movement prediction unit.
FIG. 7 is a diagram illustrating the configuration of a movement prediction map and a prediction route map managed by a user movement prediction unit.
FIG. 8 is a diagram illustrating a flow of processing for generating a predicted route map in a user movement prediction unit.
FIG. 9 is a diagram illustrating a flow of processing for confirming whether a mobile terminal is moving according to a predicted route map in a user movement prediction unit.
FIG. 10 is a diagram for explaining a processing flow of a process migration processing unit.
FIG. 11 is a diagram illustrating a method for moving the contents of an address space in a process migration processing unit.
FIG. 12 is a diagram illustrating a configuration of a mobile terminal management table according to the second embodiment of the present invention.
FIG. 13 is a diagram illustrating the configuration of a process management table according to the second embodiment of the present invention.
FIG. 14 is a diagram illustrating a configuration of a movement prediction map according to the second embodiment of the present invention.
FIG. 15 is a diagram illustrating a process flow of a process migration processing unit according to the second embodiment of the present invention.
[Explanation of symbols]
1 network

Claims (18)

A plurality of radio base stations connected via a network;
A plurality of computers connected via the network;
In a communication system having a mobile terminal connectable to the network via the radio base station,
A process migration method for moving a process executed by the mobile terminal to a first computer that is one of the plurality of computers to another computer that is one of the plurality of computers. There,
A mobile terminal destination prediction step for predicting a destination of the mobile terminal;
The destination is more than the network distance from the destination wireless base station that includes the destination predicted in the mobile terminal destination prediction step within the wireless communicable range to the first computer that is executing the process. A process destination search step for searching for a second computer that is close to the network distance from the radio base station; and
When there is a second computer in the process destination search step,
(A) A copy of the migration target process is generated in the first computer, and the copy is executed while generating an execution record of the migration target process in the first computer and the copy from the first computer to the second computer. And a first step of restoring the process to be moved based on the copy in the second computer, and
(B) The operation of the migration target process being executed on the first computer is stopped, and the execution record generated between the start of execution of the first procedure and the stop of the migration target process is first A second stage procedure for transmitting the operation of the process to be moved in the second computer based on the execution record, from the computer to the second computer,
A process moving step of executing a process including: moving a process being executed on the first computer to the second computer;
A determination step of determining whether or not the mobile terminal is moving toward the destination predicted in the mobile terminal destination prediction step;
A stopping step of stopping the process of the process moving step when it is determined in the determining step that the mobile terminal has moved to a location different from the destination predicted in the mobile terminal destination prediction step. When,
Process migration method comprising: In the mobile terminal destination prediction step,
In addition to forecasting the destination, forecasting the forecast destination,
In the process transfer step,
After the determination step determines that the mobile terminal has reached the prediction confirmation destination, the execution of the second stage procedure is started.
The process migration method according to claim 1 . In the cancellation step,
When it is determined in the determination step that the mobile terminal is moving to a location different from the destination predicted in the mobile terminal destination prediction step,
When the state is after the start of execution of the first procedure of the process transfer step and before the start of execution of the second procedure of the process transfer step,
Stopping the process of the process movement step and executing the mobile terminal movement destination prediction step again,
The process migration method according to any one of claims 1 and 2 . In the cancellation step,
When it is determined in the determination step that the mobile terminal is moving to a location different from the destination predicted in the mobile terminal destination prediction step,
If it is in a state after the execution of the second procedure of the process movement step,
Completing the process movement step;
The process migration method according to any one of claims 1 to 3 . In the cancellation step,
When it is determined in the determination step that the mobile terminal is moving to a location different from the destination predicted in the mobile terminal destination prediction step,
If it is in a state after the execution of the second procedure of the process movement step,
The process of the process movement step is stopped, the movement target process is operated again in the first computer, and the movement destination prediction step is executed again.
The process migration method according to any one of claims 1 to 3 . A plurality of computers commonly connected via a network;
  A plurality of radio base stations connected to the network;
  Each of the plurality of computers is
  A destination prediction unit that predicts a destination of a mobile terminal connected to the network via the wireless base station;
  A process execution unit that executes a process in response to a request from the mobile terminal;
  A location monitoring unit for monitoring the location of the mobile terminal;
  The network-like distance from the destination radio base station rather than the network-like distance from the destination radio base station including the destination predicted by the destination prediction unit in the radio communication range to the computer currently executing the process A process destination search unit that searches for other computers that are close to each other, and
    (A-1) a copy generation unit that generates a copy of the process to be moved;
    (A-2) a copy transmission unit for transmitting the copy to the other computer;
    (A-3) an execution record generation unit that executes the migration target process while generating an execution record;
    (A-4) a copy receiving unit for receiving the copy from the outside, and
    (A-5) A process restoration unit that restores a migration target process using the copy,
A first process movement processing unit having
    (B-1) a process stop control unit for stopping the execution of the movement target process;
    (B-2) an execution record transmitting unit for transmitting the execution record to the other computer;
    (B-3) an execution record receiving unit that receives the execution record from the outside, and
    (B-4) A process reproduction unit that reproduces the operation of the movement target process using the execution record;
A second process movement processing unit having
  A determination unit that determines whether or not the mobile terminal is moving toward a destination predicted by the mobile terminal destination prediction unit;
  When the determination unit determines that the mobile terminal has moved to a location different from the destination predicted by the mobile terminal destination prediction unit, the processing of the first process movement processing unit or the A movement control unit for stopping the processing of the second process movement processing unit;
A communication system comprising:   The mobile terminal destination prediction unit includes a prediction confirmation destination prediction unit that predicts a prediction confirmation destination,
  The movement control unit starts processing of the second process movement processing unit when the determination unit determines that the mobile terminal has reached the prediction confirmation destination.
The communication system according to claim 6. The movement control unit
    When the determination unit determines that the mobile terminal has moved to a location different from the prediction of the mobile terminal destination prediction unit, when the process of the first process mobile unit is being executed,
    The process of the first process moving unit is stopped, and the mobile terminal moving destination prediction unit is made to predict the moving destination again.
The communication system according to any one of claims 6 and 7.   The movement control unit
    When the determination unit determines that the mobile terminal has moved to a location different from the prediction of the mobile terminal destination prediction unit, when the process of the second process mobile unit is being executed,
    Completing the processing of the second process moving unit;
The communication system according to any one of claims 6 to 8.   The movement control unit
    When the determination unit determines that the mobile terminal has moved to a location different from the prediction of the mobile terminal destination prediction unit, when the process of the second process movement unit is being executed, Cancel the processing of the second process moving part,
    While resuming the operation of the movement target process on the source computer, the mobile terminal destination prediction unit is made to predict the destination again.
The communication system according to any one of claims 6 to 8.   A communication unit that communicates by connecting to a network;
  A process execution unit that executes a process in response to a request from a mobile terminal connected to the network;
  A location monitoring unit for monitoring the location of the mobile terminal;
  A destination prediction unit for predicting a destination of the mobile terminal;
  The network distance from the destination radio base station rather than the network distance from the destination radio base station that includes the destination predicted by the destination prediction unit in the radio communication range to the computer that is currently executing the process. A process destination search unit that searches for other computers that are close to each other, and
    (A-1) a copy generation unit that generates a copy of the process to be moved;
    (A-2) a copy transmission unit that transmits the copy to the other computer; and
    (A-3) an execution record generation unit that executes the migration target process while generating an execution record;
A first process transfer processing unit having
    (B-1) a process stop control unit that stops execution of the process to be moved; and
    (B-2) an execution record transmitting unit for transmitting the execution record to the other computer;
A second process transfer processing unit having
  A determination unit that determines whether or not the mobile terminal is moving toward a destination predicted by the mobile terminal destination prediction unit;
  When the determination unit determines that the mobile terminal has moved to a location different from the destination predicted by the mobile terminal destination prediction unit, the processing of the first process transfer processing unit or the first A movement control unit for stopping the processing of the two-process transfer processing unit;
A computer with   The mobile terminal destination prediction unit includes a prediction confirmation destination prediction unit that predicts a prediction confirmation destination,
  The movement control unit starts processing of the second process transfer processing unit when the determination unit determines that the mobile terminal has reached the prediction confirmation destination.
The computer according to claim 11.   The movement control unit
    When the determination unit determines that the mobile terminal has moved to a location different from the prediction of the mobile terminal destination prediction unit, when the process of the first process transfer unit is being executed,
    Canceling the processing of the first process transfer unit, causing the mobile terminal destination prediction unit to predict the destination again,
The computer according to any one of claims 11 and 12.   The movement control unit
    When the determination unit determines that the mobile terminal has moved to a location different from the prediction of the mobile terminal destination prediction unit, when the process of the second process transfer unit is being executed,
    Completing the processing of the second process transfer unit;
The computer according to any one of claims 11 to 13.   The movement control unit
    When the determination unit determines that the mobile terminal has moved to a location different from the prediction of the mobile terminal destination prediction unit, when the process of the second process transfer unit is being executed,
    Canceling the processing of the second process transfer unit, restarting the operation of the movement target process, and causing the mobile terminal destination prediction unit to predict the destination of the mobile terminal again,
The computer according to any one of claims 11 to 13.   A communication unit that communicates with other computers via a network;
  A process execution unit that executes a process in response to a request from a mobile terminal connected to the network;
    (C-1) a copy receiving unit that receives a copy of the migration target process via the network; and
    (C-2) a first process acceptance processing unit having a process restoration unit that restores the migration target process using the copy;
    (D-1) an execution record receiving unit that receives an execution record of the migration target process after the copy generation via the network; and
    (D-2) A process playback unit that plays back the operation of the migration target process using the execution record;
A second process acceptance processing unit having
  A movement control unit for stopping the processing of the first process acceptance processing unit or the processing of the second process acceptance processing unit when a cancellation instruction is received via the network;
A computer with   Location monitoring means for monitoring the location of a mobile terminal connected to the network;
  A predicted destination receiving unit that receives the predicted destination of the mobile terminal via the network;
  A determination unit for determining whether or not the mobile terminal has moved to the predicted destination;
Have
  The movement control unit, when the determination unit determines that the mobile terminal has moved to a location different from the predicted movement destination, the process of the first process reception processing unit or the second process reception processing unit Stop processing
The computer according to claim 16. Communication means for communicating with other computers via a network;
Process execution means for executing a process in response to a request from a mobile terminal connected to the network via a radio base station connected to the network;
Location monitoring means for monitoring the location of the mobile terminal;
A destination prediction unit that predicts a destination and a prediction confirmation destination of the mobile terminal;
The network distance from the destination radio base station is closer to the network than the network distance from the destination radio base station to the local computer including the destination predicted by the destination prediction unit within the wireless communicable range. A process destination search unit that searches for computers
A first process migration transmission processing unit that generates a copy of the process being executed and transmits the copy to the first computer;
Second process migration transmission processing for stopping the process being executed and transmitting the difference from the copy to the first computer after it is determined by the location monitoring means that the mobile terminal has reached the prediction confirmation destination And
Obtaining the current location of the mobile terminal from the location monitoring means;
When it is determined that the mobile terminal is moving toward a position different from the prediction, the destination prediction unit is made to predict the destination again, and the process destination search unit is made to move the destination computer again. To search for the first process migration transmission processing unit again,
When the mobile terminal has reached the prediction confirmation destination, a control unit that causes the second process migration transmission processing unit to perform processing;
Having a calculator.

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