JP3861875B2 - E-mail server system, e-mail service method and program, and server apparatus - Google Patents

Description

  The present invention relates to an e-mail server system, an e-mail service method, a program, and a server device, and more particularly, to an e-mail server system, an e-mail service method, a program, and a server device that enable service continuation when a storage failure occurs in a mailbox.

  A conventional electronic mail system includes, for example, a plurality of mail servers and a client that transmits / receives an electronic mail by accessing any of the plurality of mail servers as disclosed in Patent Document 1. This system shares a file system for storing electronic mail among a plurality of mail servers. The client can log in to any mail server with the same account. When a failure occurs in a mail server, the client sends and receives e-mails by accessing other mail servers. In this system, failure prevention is performed by multiplexing a file system for storing an electronic mail by mirroring or RAID (Redundant Arrays of Inexpensive Discs).

  Further, Patent Document 2 and Patent Document 3 are examples of a control method for switching to an alternative mailbox in such an electronic mail system.

  Patent Document 2 discloses a mailbox control in an e-mail system in which a first mailbox and a second mailbox are assigned to each subscriber and the second mailbox is used when the first mailbox cannot be used. The method is described. In the method of Patent Document 2, two mailboxes are allocated in advance for each user, and double the current resources are required.

  The control method of Patent Document 3 includes a mailbox monitoring means and a temporary mailbox used for a temporary storage location of mail. When the mailbox monitoring means detects that a situation in which mail cannot be stored in the mailbox has occurred, the mail storage destination is changed from the mailbox to the temporary mailbox. In Patent Document 3, a provisional mailbox is prepared in advance.

  Neither Patent Document 2 nor Patent Document 3 exclusively controls the creation / deletion of the current mailbox during the service by the alternative mailbox.

  In both Patent Documents 2 and 3, service switching to an alternative mailbox is performed on a mailbox basis. In a large-scale system with a large hard disk capacity, it is assumed that tens of thousands of user mailboxes exist on the hard disk. In such a large-scale system, in the control methods of Patent Document 2 and Patent Document 3, a transaction for switching mailboxes occurs for each mailbox, and a transaction for switching mailboxes to a device that manages the mailboxes. The number becomes enormous.

JP 2001-86152 A JP-A-2-111136 JP-A-2-213252

  However, the background art described above has the following problems.

  That is, the alternative mailbox is prepared in advance, and the alternative mailbox is not generated when necessary.

  In addition, the creation / deletion of the active mailbox in the alternative service due to a failure is not controlled exclusively, so there is a risk of creating an error state due to the creation / deletion of the active mailbox.

  In addition, since switching to an alternative mailbox is performed in units of mailboxes, transactions for switching mailboxes become enormous.

  An object of the present invention is to provide an electronic mail server system, an electronic mail service method and program, and a server device that solve the above-described problems.

The electronic mail server system according to the first aspect of the present invention includes a first table for managing a set of a user ID that is an identifier of an electronic mail user, a mailbox ID that is an identifier of an active mailbox, and a logical ID of the active storage device. A second table for managing a set of a logical ID of the active storage device and a physical ID of the active storage device, the first table based on the user ID extracted and extracted from the received electronic mail, Means for searching the second table to acquire the mailbox ID and the physical ID of the active storage device; and specifying the mailbox ID to perform an e-mail process on the active storage device or the alternative storage device of the physical ID. Means for requesting and having a working mailbox having the mailbox ID A working storage device which performs the requested e-mail processing for over mailbox, the physical of said means for assigning an alternate storage device when a failure of the active storage devices, the failure on the second table is generated working storage device Means for rewriting the ID with the physical ID of the alternative storage device; and an alternative storage device that generates an alternative mailbox having the mailbox ID and performs the requested email processing on the alternative mailbox. .

An electronic mail server system according to a second aspect of the present invention includes a mail transmission / reception request accepting device, a user-to-mailbox management device, an active mailbox storage device, an alternative mailbox storage device, an entrance / exit management device, and a maintenance operation device. The mail transmission / reception request accepting device receives a mail write / read / delete request, and obtains a mailbox ID and a physical storage ID corresponding to the user ID from the user-to-mailbox management device. Means for performing an e-mail write / read / delete request by designating the acquired mailbox ID to the active mailbox storage device or the alternative mailbox storage device having the acquired physical storage ID The user-to-mailbox management device comprises Logical mailbox ID table for registering correspondence between user ID which is identifier of electronic mail user, mailbox ID which is identifier of active mailbox and logical storage ID of active mailbox storage device, and logical storage of active mailbox storage device Means for holding a physical storage ID table for registering the correspondence between the ID and the physical storage ID of the active mailbox storage device, receiving a user ID from the mail transmission / reception request accepting device, the logical mailbox ID table, and the physical storage Means for searching an ID table to extract a mailbox ID and a physical storage ID corresponding to the received user ID; and for sending and receiving the extracted mailbox ID and physical storage ID to the mail transmission / reception request The active mailbox storage apparatus holds an active mailbox identified by a mailbox ID, and specifies an e-mail written with a mailbox ID specified by the mail transmission / reception request accepting apparatus. Means for receiving a load / read / delete request; and means for writing / reading / deleting an e-mail to / from an active mailbox having the designated mailbox ID, wherein the alternative mailbox storage device comprises: Means for receiving an e-mail write / read / delete request designating a mailbox ID from the mail transmission / reception request accepting device, and the designated when there is no alternative mailbox having the designated mailbox ID Means for generating an alternative mailbox having a mailbox ID, and the specified Means for writing / reading / deleting an e-mail to / from an alternative mailbox having a mailbox ID, wherein the admission / exit management device includes a user ID, a mailbox ID, and a physical storage ID of the active mailbox storage device, The physical mailbox ID table for registering the correspondence between the physical storage and the physical storage ID table for registering the correspondence between the physical storage ID of the active mailbox storage device, the number of assignments, and the assignment stop flag. Means for searching the physical storage allocation table and selecting a working mailbox storage device; means for sending a request to create a working mailbox having a designated mailbox ID to the selected working mailbox storage device; and When withdrawal is specified, the physical Means for searching the mailbox ID table to identify the mailbox ID and the active mailbox storage device, and means for transmitting a deletion request for the active mailbox having the specified mailbox ID to the specified active mailbox storage device; The maintenance operation device comprises a physical unit of the failed active mailbox storage device on the physical storage ID table in the user-to-mailbox management device when the active mailbox storage device fails. A means for rewriting the storage ID with the physical storage ID of the alternative mailbox storage device is provided.

The electronic mail server system according to a third aspect of the present invention is the electronic mail server system according to the second aspect , wherein the maintenance operation device corresponds to the active mailbox storage device on the physical storage allocation table when the active mailbox storage device fails. And an entry / exit management device having means for selecting a current mailbox storage device from among the current mailbox storage devices whose assignment stop flag is OFF. And

An electronic mail service method according to a fourth aspect of the present invention includes a mail transmission / reception request accepting apparatus, a user-to-mailbox management apparatus, an active mailbox storage apparatus, an alternative mailbox storage apparatus, an entrance / exit management apparatus, and a maintenance operation apparatus. And a logical mailbox ID table for registering the correspondence between the user ID, the mailbox ID, and the logical storage ID of the active mailbox storage device, and the logical storage ID of the active mailbox storage device and the physical storage of the active mailbox storage device An e-mail service method for an e-mail server system having a physical storage ID table for registering correspondence with an ID, wherein the e-mail transmission / reception request accepting apparatus receives an e-mail write / read / delete request from a user terminal , The user-to-mailbox management apparatus requests a mailbox ID and a physical storage ID corresponding to the received user ID, and the user-to-mailbox management apparatus sends a mailbox ID corresponding to the user ID from the mail transmission / reception request accepting apparatus. The physical storage ID acquisition request is received, the mailbox ID and the logical storage ID are specified by searching the logical mailbox ID table by the user ID, and the physical storage ID table is searched by the specified logical storage ID. The physical storage ID is identified, and the mailbox ID and the physical storage ID are transmitted to the mail transmission / reception request reception device. The mail transmission / reception request reception device includes a mailbox ID and a physical storage ID corresponding to the user ID, The user vs. mail box And a request for writing / reading / deleting an email by designating the mailbox ID to the active mailbox storage device having the physical storage ID, and the active mailbox storage device A request for writing / reading / deleting an e-mail with a specified mailbox ID is received from the mail transmission / reception request accepting apparatus, and an e-mail is written / read / deleted with respect to a working mailbox having the specified mailbox ID was carried out, the maintenance operation device, wherein when the current mailbox storage device failure is notified of the occurrence, the physical storage ID alternative mailbox storage device to replace the working mailbox storage device where the failure has occurred And obtain the above-mentioned alternative mailbox stray The physical storage ID of the active mailbox storage device in which the failure has occurred in the physical storage ID table is rewritten with the physical storage ID of the storage device.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the mail transmission / reception request accepting apparatus receives a request for writing / reading / deleting an electronic mail from a user terminal, and the mail corresponding to the received user ID. A box ID and a physical storage ID are requested to the user-to-mailbox management apparatus, and the user-to-mailbox management apparatus sends an acquisition request for a mailbox ID and a physical storage ID corresponding to the user ID from the mail transmission / reception request receiving apparatus. Receiving, specifying the mailbox ID and the logical storage ID by searching the logical mailbox ID table by the user ID, searching the physical storage ID table by the specified logical storage ID, and specifying the physical storage ID; The mailbox ID and the physical storage ID are The mail transmission / reception request reception device receives the mailbox ID and physical storage ID corresponding to the user ID from the user-to-mailbox management device, and has the physical storage ID. An email writing / reading / deleting request is transmitted to the mailbox storage device by designating the mailbox ID, and the alternative mailbox storage device is an electronic device that designates the mailbox ID from the mail transmission / reception request receiving device. A mail write / read / delete request is received, and an electronic mail is written / read / deleted from / to an alternative mailbox having a designated mailbox ID.

An electronic mail service method according to a sixth invention of the present application is the fifth invention, wherein the substitute mailbox storage device has a designated mailbox ID if there is no substitute mailbox having the designated mailbox ID. An alternative mailbox is generated.

An e-mail service program according to a seventh aspect of the present invention includes a mail transmission / reception request accepting device, a user-to-mailbox management device, a working mailbox storage device, an alternative mailbox storage device 1400, an entrance / exit management device, and a maintenance operation. And an electronic mail server system having a logical mailbox ID table for registering a correspondence between a user ID, a mailbox ID and a logical storage ID, and a physical storage ID table for registering a correspondence between a logical storage ID and a physical storage ID The mail transmission / reception program of the present invention is such that the mail transmission / reception request accepting device receives a request for writing / reading / deleting an electronic mail from a user terminal, a mailbox ID corresponding to the received user ID and a physical Stray A function for requesting an ID from the user-to-mailbox management apparatus, a function for the user-to-mailbox management apparatus to receive an acquisition request for a mailbox ID and a physical storage ID corresponding to a user ID from the mail transmission / reception request receiving apparatus; A function for searching the logical mailbox ID table by the user ID and specifying a mailbox ID and a logical storage ID, a function for searching the physical storage ID table by the specified logical storage ID and specifying a physical storage ID, A function of transmitting a mailbox ID and the physical storage ID to the mail transmission / reception request reception device; and the mail transmission / reception request reception device indicates a mailbox ID and a physical storage ID corresponding to a user ID to the user-to-mailbox management device To receive from A function of transmitting an e-mail write / read / delete request to the active mailbox storage device having the physical storage ID by designating the mailbox ID; and the active mailbox storage device is configured to receive the mail transmission / reception request A function of receiving an e-mail write / read / deletion request designating a mailbox ID from a function of performing e-mail write / read / deletion on an active mailbox having a designated mailbox ID, A function for obtaining a physical storage ID of an alternative mailbox storage device that replaces the failed active mailbox storage device when the maintenance operation device is notified that a failure has occurred in the active mailbox storage device The obtained alternative mailbox storage The function of rewriting the physical storage ID of the active mailbox storage apparatus in which the failure has occurred in the physical storage ID table is realized with the physical storage ID of the apparatus.

The e-mail service program of the eighth invention of the present application corresponds to the function of the e-mail transmission / reception request accepting device receiving the e-mail write / read / delete request from the user terminal and the received user ID in the seventh invention. A function for requesting the user-to-mailbox management apparatus for a mailbox ID and a physical storage ID, and the user-to-mailbox management apparatus obtains a mailbox ID and a physical storage ID corresponding to the user ID from the mail transmission / reception request accepting apparatus. A function of receiving a request, a function of searching the logical mailbox ID table by the user ID and specifying a mailbox ID and a logical storage ID, and searching the physical storage ID table by the specified logical storage ID and a physical storage ID Function to identify the mailbox A function of transmitting D and the physical storage ID to the mail transmission / reception request reception device; the mail transmission / reception request reception device receives a mailbox ID and a physical storage ID corresponding to a user ID from the user-to-mailbox management device; A function to send an email write / read / delete request by designating the mailbox ID to an alternative mailbox storage device having the physical storage ID, and the alternative mailbox storage device sends and receives the mail A function for receiving a request for writing / reading / deleting an e-mail with a specified mailbox ID from a request receiving device, and writing / reading / deleting an e-mail with respect to an alternative mailbox having the specified mailbox ID Function.

The electronic mail service program according to the ninth aspect of the present invention is the electronic mail service program according to the eighth aspect , in which, if the alternative mailbox storage apparatus does not have an alternative mailbox having the specified mailbox ID, A function to generate an alternative mailbox is realized.

A server device according to a tenth aspect of the present invention is a mailbox management server device that manages correspondence between an e-mail user and a mailbox that stores a received e-mail, and includes a user ID that is a user identifier and a mailbox identifier. A first table for managing a set of a mailbox ID and a logical ID of a device where the mailbox exists, and a set of a logical ID of the device where the mailbox exists and a physical ID of the device where the mailbox exists Search the second table to be managed, the means for receiving the acquisition request for the mailbox ID for the user ID and the physical ID of the device in which the mailbox exists, the first table, and the second table. Means for extracting a mailbox ID for the user ID and a physical ID of a device in which the mailbox exists; Means for transmitting the extracted mailbox ID and the physical ID of the device in which the mailbox exists to the request source; and the physical ID of the device in which the mailbox on the second table exists from an externally designated device Means for rewriting the physical ID.

  The effect of the present invention is that e-mail transmission / reception can be continued using an alternative mailbox even after the failure of the mailbox occurs.

  The reason is that means for generating an alternative mailbox and means for storing an electronic mail for the generated alternative mailbox are provided.

  The electronic mail server system of the present invention switches to an alternative storage apparatus when a failure occurs in a storage apparatus in which a mailbox exists, and automatically generates an alternative mailbox in the alternative storage apparatus and continues the electronic mail service. It is characterized by.

  More specifically, the storage device is managed by a combination of a logical ID (identifier) and a physical ID, and the active storage is set by setting the ID of the active storage device or the ID of the alternative storage device in the physical ID. Switch between the device and the alternative storage device. Further, while a failure occurs in the active storage device and the alternate storage device is in service, exclusive control is performed so that the active storage device in which the failure has occurred is not handled.

Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an electronic mail server system according to the present invention.
FIG. 2 is a diagram for explaining the electronic mail server system of the present invention.

  Referring to FIG. 1, an e-mail server system capable of continuing service in the event of a storage failure according to an embodiment of the present invention includes a mail transmission / reception request accepting apparatus 1100, a user-to-mailbox management apparatus 1200, and a working mailbox storage apparatus 1300. And an alternative mailbox storage device 1400, an entrance / exit management device 1500, and a maintenance operation device 1600. These devices are connected to each other via a network 1700 such as a LAN (local area network). Note that the number of active mailbox storage devices 1300 and alternative mailbox storage devices 1400 is arbitrary.

  The mail transmission / reception request accepting apparatus 1100 is an information processing apparatus such as a server that operates under program control. When receiving a request for writing / reading / deleting an e-mail from the user terminal 1800 via the network 1900 such as the Internet, the mail transmission / reception request receiving apparatus 1100 sets a mailbox ID and a physical storage ID corresponding to the user ID of the requesting user. Obtained from the user-to-mailbox management apparatus 1200. The mail transmission / reception request receiving apparatus 1100 transmits a request for writing / reading / deleting an electronic mail related to the acquired mailbox ID to the active mailbox storage apparatus 1300 or the alternative mailbox storage apparatus 1400 having the acquired physical storage ID. To do.

  The user-to-mailbox management apparatus 1200 is an information processing apparatus such as a server that operates under program control. The user-to-mailbox management apparatus 1200 holds and manages a logical mailbox ID table 1210 and a physical storage ID table 1220. In response to the mail box ID and physical storage ID acquisition request corresponding to the user ID from the mail transmission / reception request receiving apparatus 1100, the user-to-mailbox management apparatus 1200 sets the mailbox ID corresponding to the received user ID to the logical mailbox ID. Extract from the table 1210, extract the physical storage ID from the physical storage ID table 1220, and return it to the mail transmission / reception request accepting apparatus 1100. Further, the user-to-mailbox management apparatus 1200 receives the user ID, the mailbox ID, and the physical storage ID from the entrance / exit management apparatus 1500 as the user joins / leaves, and registers / deletes it in the logical mailbox ID table 1210. .

  The logical mailbox ID table 1210 registers the correspondence between user IDs, mailbox IDs, and logical storage IDs. There are entries for the user IDs, and the user ID is used as a key. The user ID and the mailbox ID are the user ID and the mailbox ID received from the entrance / exit management device 1500. The logical storage ID is a logical storage ID corresponding to the physical storage ID received from the entrance / exit management apparatus 1500 on the physical storage ID table 1220.

  The physical storage ID table 1220 registers the correspondence between the logical storage ID and the physical storage ID, and has entries for the physical storage ID. The user-to-mailbox management apparatus 1200 creates a physical storage ID table 1220 for the physical storage ID of the active mailbox storage apparatus 1300 existing in the system at the time of system construction, and sets the physical storage ID of the alternative mailbox storage apparatus 1400 as the physical storage ID. It is not created for it. In the logical storage ID, a value arbitrarily determined by the user-to-mailbox management apparatus 1200 so as to be unique with respect to the physical storage ID of the active mailbox storage apparatus 1300 is registered.

  The active mailbox storage device 1300 is an information processing device such as a server that operates under program control, and has a function of communicating using a protocol such as SMTP (Simple Mail Transfer Protocol) or a dedicated message. The active mailbox storage device 1300 holds a physical storage ID and is specified by the physical storage ID. The active mailbox storage device 1300 holds an active mailbox 1310 for each user identified by the mailbox ID. Upon receiving an e-mail write / read / delete request from the mail transmission / reception request accepting apparatus 1100, the active mailbox storage apparatus 1300 writes / reads / deletes an e-mail in the active mailbox 1310 for each user. Also, the active mailbox storage device 1300 receives the stay mail write request from the alternative mailbox storage device 1400 and adds it to the stay mail in the active mailbox 1310 for each user. A staying e-mail refers to an e-mail that has not been deleted yet in the life cycle of writing / reading / deleting.

  The working mailbox 1310 has a mailbox ID and is specified by this. The mailbox ID is information indicating the location of the active mailbox 1310 for each user in the active mailbox storage device 1300, and becomes directory information, a database key, or the like depending on the method of realizing the active mailbox storage device 1300.

  The alternative mailbox storage device 1400 is an information processing device such as a server that operates under program control, and has a function of communicating using a protocol such as SMTP or a dedicated message. The alternative mailbox storage device 1400 holds a physical storage ID and is specified by the physical storage ID. When the alternative mailbox storage apparatus 1400 receives an e-mail write / read / delete request from the e-mail transmission / reception request accepting apparatus 1100, the alternative mailbox storage apparatus 1400 is replaced if there is an alternative mailbox 1410 for each user identified by the mailbox ID. E-mail is written / read / deleted in the mail box 1410. The alternative mailbox storage device 1400 automatically generates an alternative mailbox 1410 when there is no alternative mailbox 1410 for each user identified by the mailbox ID, and writes an email to the automatically generated alternative mailbox 1410. I do. Further, when the alternative mailbox storage apparatus 1400 receives a stay mail merge request, it transmits a stay mail write request to the active mailbox storage apparatus 1300. Further, when receiving the substitute service post-processing request, the substitute mailbox storage apparatus 1400 deletes all the substitute mailboxes 1410 and returns them to the initial state.

  The alternative mailbox 1410 has a mailbox ID and is specified thereby. The mailbox ID is information indicating the location of the alternative mailbox 1410 for each user in the alternative mailbox storage apparatus 1400, and becomes directory information, a database key, or the like depending on the method of realizing the alternative mailbox storage apparatus 1400.

  The entrance / exit management device 1500 is an information processing device such as a server that operates under program control, and manages the entrance / exit of e-mail users. The entrance / exit management device 1500 assigns a user ID and a mailbox ID to a user who joins. In addition, the entrance / exit management device 1500 holds and manages a physical mailbox ID table 1510 and a physical storage allocation table 1520.

  The physical mailbox ID table 1510 registers the correspondence between the user ID, the mailbox ID, and the physical storage ID, and has entries for the user ID. . The user ID is a user identifier that the entrance / exit management device 1500 gives to a user who has joined. The user ID is arbitrarily determined so as to be unique to the user, and is used in e-mail or the like. The mailbox ID is a mailbox identifier assigned by the entrance / exit management device 1500 to the mailbox corresponding to the user ID. The mailbox ID is a value that identifies the active mailbox 1310 held by the active mailbox storage device 1300. The physical storage ID is a physical storage ID selected from physical storage IDs whose allocation stop flag in the physical storage allocation table 1520 is OFF.

  The physical storage allocation table 1520 registers the correspondence between physical storage IDs, allocation numbers, and allocation stop flags, and has entries for physical storage IDs. The physical storage allocation table 1520 is created for the physical storage ID of the active mailbox storage device 1300 existing in the system at the time of system construction. The physical storage ID is a physical storage identifier of the active mailbox storage device 1300, and is, for example, a device number or an IP (Internet Protocol) address. The number of allocations indicates the number of active mailboxes created in the active mailbox storage device 1300 indicated by the physical storage ID. The initial value of the allocation number is zero. The allocation stop flag indicates whether or not the active mailbox storage device 1300 indicated by the physical storage ID is in an allocation stop state. When the allocation stop flag is OFF, the working mailbox 1310 can be created / deleted. When the allocation stop flag is ON, since the switch to the alternative mailbox storage device 1400 is being performed, the current mailbox 1310 cannot be created / deleted. The initial value of the allocation stop flag is OFF.

  Also, the joining / leaving management device 1500 sends a mailbox allocation request or deletion request to the active mailbox storage device 1300 having a physical storage ID whose allocation stop flag of the physical storage allocation table 1520 is OFF, and the active mailbox storage The allocation number in the physical storage allocation table 1520 corresponding to the physical storage ID of the device 1300 is incremented or decremented.

  In addition, when a user is instructed to join, the joining / leaving management apparatus 1500 selects a physical storage ID whose allocation stop flag in the physical storage allocation table 1520 is OFF, and adds a user ID and a mailbox ID for the joining user. The selected physical storage ID is registered in the physical mailbox ID table 1510. In addition, when the user withdrawal instruction is given, the entrance / exit management apparatus 1500 deletes the user ID, mailbox ID, and physical storage ID for the canceled user from the physical mailbox ID table 1510. Further, the entrance / exit management device 1500 transmits the user ID, the physical storage ID, and the mailbox ID to the user-to-mailbox management device 1200 when the user joins / leaves.

  The maintenance operation device 1600 is an information processing device such as a server that operates under program control. The maintenance operation device 1600 manages the correspondence between the active mailbox storage device and its physical storage ID and the correspondence between the alternative mailbox storage device and its physical storage ID.

  When the failure of the active mailbox storage device 1300 is notified, the maintenance operation device 1600 stores the physical storage allocation table 1520 of the admission / reception management device 1500 based on the notified physical storage ID of the active mailbox storage device 1300. The allocation stop flag corresponding to the physical storage ID is turned ON. The maintenance operation device 1600 displays a list of the alternative mailbox storage device 1400 and its physical storage ID, selects the alternative mailbox storage device 1400 from the display list, and acquires the physical storage ID. The maintenance operation device 1600 sets the physical storage ID of the failed active mailbox storage device 1300 on the physical storage ID table 1220 of the user-to-mailbox management device 1200 as the acquired physical storage ID of the alternative mailbox storage device 1400. Rewrite. At this time, the maintenance operation device 1600 saves the physical storage ID of the working mailbox storage device 1300 in preparation for the case where the working mailbox storage device 1300 recovers from the failure.

  Further, when the current mailbox storage device 1300 recovers from a failure, the maintenance operation device 1600 uses the physical storage ID of the physical storage ID table 1220 of the user-to-mailbox management device 1200 as the physical storage ID of the alternative mailbox storage device 1400. The ID is rewritten to the physical storage ID of the original working mailbox storage device 1300. The maintenance operation device 1600 instructs the alternative mailbox storage device 1400 to merge the stay mail. The maintenance operation device 1600 turns off the allocation stop flag corresponding to the physical storage ID of the entrance / exit management device 1500, and requests the substitute mailbox storage device 1400 for the substitute service post-processing.

Next, the operation of the embodiment of the best mode for carrying out the present invention will be described in detail with reference to FIGS.
FIG. 3 is a diagram showing an operation flow at the time of e-mail write / read / delete request processing in the e-mail transmission / reception request accepting apparatus.
FIG. 4 is a diagram showing an operation flow when receiving an acquisition request for a mailbox ID and a physical storage ID corresponding to the user ID in the user-to-mailbox management apparatus.
FIG. 5 is a diagram showing an operation flow when the active mailbox storage apparatus accepts a mailbox creation / deletion request from the entrance / exit management apparatus.
FIG. 6 is a diagram showing an operation flow when the active mailbox storage apparatus accepts an e-mail write / read / delete request from the mail transmission / reception request accepting apparatus.
FIG. 7 is a diagram showing an operation flow when the alternative mailbox storage apparatus accepts an e-mail write / read / delete request from the mail send / receive request accepting apparatus.
FIG. 8 is a diagram showing an operation flow when the alternative mailbox storage device accepts a stay mail merge request from the maintenance operation device.
FIG. 9 is a diagram showing an operation flow when the alternative mailbox storage apparatus accepts an alternative service post-processing request from the maintenance operation apparatus.
FIG. 10 is a diagram showing an operation flow of assignment control of the entrance / exit management device.
FIG. 11 is a diagram showing an operation flow of deletion control of the entrance / exit management device.
FIG. 12 is a diagram showing an operation flow when the maintenance operation device accepts a switch request to the alternative mailbox storage device.
FIG. 13 is a diagram showing an operation flow when the maintenance operation device accepts a switch request to the active mailbox storage device.

  First, an operation when the mail transmission / reception request receiving apparatus 1100 receives an e-mail write / read / delete request process will be described with reference to FIG.

  In step 2100, mail transmission / reception request receiving apparatus 1100 receives an email write / read / delete request from the user terminal. At this time, the user ID is also transmitted from the user terminal.

  In step 2200, the mail transmission / reception request accepting apparatus 1100 requests the user-to-mailbox management apparatus 1200 for the mailbox ID and physical storage ID corresponding to the user ID, and the user receives the mailbox ID and physical storage ID corresponding to the user ID. Acquired from the mailbox management apparatus 1200.

  In step 2300, the mail transmission / reception request accepting apparatus 1100 designates the mailbox ID to the active mailbox storage apparatus 1300 having the physical storage ID or the alternative mailbox storage apparatus 1400, and issues an e-mail write / read / delete request. Send.

  Next, an operation when the user-to-mailbox management apparatus 1200 receives an acquisition request for a mailbox ID and a physical storage ID corresponding to the user ID will be described with reference to FIG.

  In step 3100, the user-to-mailbox management apparatus 1200 receives an acquisition request for a mailbox ID and a physical storage ID corresponding to the user ID from the mail transmission / reception request reception apparatus 1100.

  In step 3200, the user-to-mailbox management apparatus 1200 searches the logical mailbox ID table 1210 to identify the mailbox ID and the logical storage ID.

  In step 3300, the user-to-mailbox management apparatus 1200 searches the physical storage ID table 1220 using the specified logical storage ID, and specifies the physical storage ID.

  In step 3400, the user-to-mailbox management apparatus 1200 returns the mailbox ID and the physical storage ID to the mail transmission / reception request reception apparatus 1100.

  Next, an operation when the active mailbox storage apparatus 1300 receives a mailbox creation / deletion request from the entrance / exit management apparatus 1500 will be described with reference to FIG.

  In step 4100, the active mailbox storage apparatus 1300 receives a mailbox creation / deletion request specifying a mailbox ID from the entrance / exit management apparatus 1500.

  In step 4200, active mailbox storage apparatus 1300 determines whether the request is for creating or deleting a mailbox.

  In step 4300, in the case of a mailbox creation request, the working mailbox storage apparatus 1300 creates a working mailbox 1310 having a designated mailbox ID.

  In step 4400, in the case of a mailbox deletion request, the active mailbox storage apparatus 1300 deletes the active mailbox 1310 having the designated mailbox ID.

  Next, an operation when the active mailbox storage apparatus 1300 receives an e-mail write / read / delete request from the mail transmission / reception request receiving apparatus 1100 will be described with reference to FIG.

  In step 5100, active mailbox storage apparatus 1300 receives an e-mail write / read / delete request designating a mailbox ID from e-mail transmission / reception request receiving apparatus 1100.

  In step 5200, active mailbox storage apparatus 1300 determines whether the request is an email write request, a read request, or a delete request.

  In step 5300, in the case of an e-mail write request, the active mailbox storage apparatus 1300 adds an e-mail to the active mailbox 1310 having the designated mailbox ID.

  In step 5400, in the case of an e-mail read request, active mailbox storage apparatus 1300 reads the e-mail from active mailbox 1310 having the specified mailbox ID and returns it to e-mail transmission / reception request accepting apparatus 1100.

  If an e-mail deletion request is made in step 5500, the active mailbox storage apparatus 1300 deletes the e-mail from the active mailbox 1310 having the designated mailbox ID.

  Next, the operation when the alternative mailbox storage device 1400 accepts an email write / read / delete request from the email transmission / reception request accepting device 1100 will be described with reference to FIG.

  In step 6100, alternative mailbox storage apparatus 1400 receives an e-mail write / read / delete request designating a mailbox ID from e-mail transmission / reception request accepting apparatus 1100.

  In step 6200, the alternative mailbox storage apparatus 1400 checks whether there is an alternative mailbox 1410 with the specified mailbox ID.

  In step 6300, if there is no alternative mailbox 1410, the alternative mailbox storage apparatus 1400 automatically generates an alternative mailbox 1410 with the specified mailbox ID.

  In step 6400, alternative mailbox storage apparatus 1400 determines whether it is a write request, a read request, or a delete request.

  In step 6500, in the case of an e-mail write request, the alternative mailbox storage apparatus 1400 adds an e-mail to the alternative mailbox 1410 having the designated mailbox ID.

  In step 6600, in the case of an e-mail read request, the alternative mailbox storage apparatus 1400 reads the e-mail from the alternative mailbox 1410 having the designated mailbox ID and returns it to the e-mail transmission / reception request receiving apparatus 1100.

  In step 6700, in the case of an e-mail deletion request, the alternative mailbox storage apparatus 1400 deletes the e-mail from the alternative mailbox 1410 having the designated mailbox ID.

  Next, the operation when the alternative mailbox storage apparatus 1400 receives a stay mail merge request from the maintenance operation apparatus 1600 will be described with reference to FIG.

  In step 7100, the alternative mailbox storage apparatus 1400 receives a stay mail merge instruction from the maintenance operation apparatus 1600. At this time, the alternative mailbox storage device 1400 also receives the physical storage ID of the active mailbox storage device 1300 that is the merge destination from the maintenance operation device 1600.

  In step 7200, a request to write an e-mail staying in all the alternative mailboxes 1410 is executed to the active mailbox storage apparatus 1300. That is, for each mailbox ID, the e-mail staying in the alternative mailbox is written to the active mailbox.

  Next, the operation when the alternative mailbox storage apparatus 1400 receives an alternative service post-processing request from the maintenance operation apparatus 1600 will be described with reference to FIG.

  In step 8100, the alternative mailbox storage device 1400 receives an alternative service post-processing request from the maintenance operation device 1600.

  In step 8200, the alternative mailbox storage apparatus 1400 deletes all the alternative mailboxes 1410.

  Next, the assignment control operation of the entrance / exit management device 1500 will be described with reference to FIG.

  In step 9100, the entrance / exit management device 1500 is instructed to assign a working mailbox or the like when joining a user. At this time, the entrance / exit management device 1500 assigns a user ID and a mailbox ID for the user to join.

  In step 9200, the entrance / exit management apparatus 1500 searches a list of physical storage IDs whose allocation stop flag is OFF on the physical storage allocation table 1520.

  In step 9300, the entrance / exit management device 1500 selects one physical storage ID to be allocated from among the searched physical storage IDs according to an appropriate selection criterion (for example, the allocation number is minimum).

  In step 9400, the entrance / exit management device 1500 requests the active mailbox storage device 1300 having the selected physical storage ID to create the active mailbox by specifying the mailbox ID.

  Next, the deletion control operation of the entrance / exit management apparatus 1500 will be described with reference to FIG.

  In step 10100, the entrance / exit management device 1500 is instructed to delete the active mailbox, etc., when the user leaves. At this time, the user ID of the user to be withdrawn is instructed.

  In step 10200, the entrance / exit management device 1500 searches the physical mailbox ID table 1510 for a mailbox ID and a physical storage ID corresponding to the user ID.

  In step 10300, the joining / leaving management device 1500 checks the allocation stop flag of the searched physical storage ID in the physical storage allocation table 1520.

  In step 10400, if the allocation stop flag is OFF, the entrance / exit management apparatus 1500 designates the mailbox ID to the active mailbox storage apparatus 1300 having the physical storage ID and makes a deletion request for the active mailbox.

  In step 10500, if the assignment stop flag is ON, the joining / withdrawing management apparatus 1500 holds the mailbox deletion request and retries after a predetermined time.

  Next, an operation when the maintenance operation device 1600 receives a request for switching to the alternative mailbox storage device will be described with reference to FIG.

  In step 11100, maintenance operation device 1600 accepts a request to switch to alternative mailbox storage device 1400. At this time, the maintenance operation device 1600 also receives the physical storage ID of the active mailbox storage device 1300 that is substituted for the alternative mailbox storage device 1400. The maintenance operation device 1600 turns on an allocation stop flag corresponding to the physical storage ID of the entrance / exit management device 1500.

  In step 11200, the maintenance operation device 1600 changes the physical storage ID corresponding to the logical storage ID of the user-to-mailbox management device 1200 to the physical storage ID of the alternative mailbox storage device 1400. At this time, the maintenance operation device 1600 saves the physical storage ID of the active mailbox storage device 1300 corresponding to the logical storage ID.

  Next, the operation when the maintenance operation device 1600 receives a request for switching to the active mailbox storage device will be described with reference to FIG.

  In step 12100, the maintenance operation device 1600 changes the physical storage ID corresponding to the logical storage ID of the user-to-mailbox management device 1200 to the physical storage ID of the active mailbox storage device 1300.

  In step 12200, maintenance operation device 1600 issues an instruction to merge the stay mail to alternative mailbox storage device 1400.

  In step 12300, the maintenance operation device 1600 turns off the allocation stop flag corresponding to the physical storage ID of the entrance / exit management device 1500.

  In this way, in the present invention, the user-to-mailbox management apparatus 1200 has a function of managing storage ID management by dividing it into logical storage ID and physical storage ID, and the alternative mailbox storage apparatus 1400 has an alternative mailbox. It has a function of automatically generating and a function of initializing an alternative mailbox. Further, the entrance / exit management device 1500 has a function of holding a storage allocation stop flag, and the maintenance operation device 1600 has a function of controlling these functions. Therefore, an alternative mailbox can be provided dynamically and promptly in the event of a failure of the active mailbox storage apparatus 1300, consistent with user entry / exit processing. In addition, after the failure of the active mailbox storage apparatus 1300 is recovered, mail that has accumulated in the alternative mailbox can be read without being lost.

  In the present invention, for example, at least one of the following effects can be achieved.

  The first effect is that e-mails after the occurrence of a failure can be transmitted and received by the alternative mailbox. The reason is that means for generating an alternative mailbox and means for storing an electronic mail for the generated alternative mailbox are provided.

  The second effect is that the switching / switching back to the alternative mailbox can be realized at high speed. The reason for this is that the table of the user-to-mailbox management device 1200 is managed using a logical storage ID in addition to the physical storage ID, and the physical of the physical storage ID table 1220 at the time of switching / switching back to an alternative mailbox. This is because means for changing the storage ID is provided. It is not necessary to change the table entries for all user IDs assigned to the active mailbox storage apparatus 1300.

  A third effect is that it is possible to avoid the occurrence of a complicated state due to an entry / exit process during service by an alternative mailbox when a storage failure occurs. In other words, the creation / deletion of a working mailbox can be avoided for a failed working mailbox storage device, and the working mailbox can be created / deleted for another working mailbox storage device. . The reason is that the maintenance operation device 1600 notifies the entrance / exit management device 1500 to stop processing of the failed storage before the service by the alternative mailbox, the entrance / exit management device 1500 sets the allocation stop flag to ON, the allocation stop state This is because there is provided means for performing an entry / exit process with respect to the active mailbox storage apparatus except the active mailbox storage apparatus.

  Next, another embodiment of the present invention will be described.

  The configuration of another embodiment of the present invention is different from the configuration of FIG. 1 described above only in the maintenance operation device. The maintenance operation device according to another embodiment of the present invention is obtained by adding means for selecting an optimal alternative mailbox storage device to the maintenance operation device 1600 of FIG. The maintenance operation device will be described below.

  The maintenance operation device has an active storage table storing a physical storage ID, a maximum capacity, and a used capacity for each active mailbox storage device, and an alternative storage table storing a physical storage ID and a maximum capacity for each alternative mailbox storage device. Possess. When the failure of the active mailbox storage device is notified, the maintenance operation device searches the active storage table and extracts the used capacity of the active mailbox storage device in which the failure has occurred. The maintenance operation device searches the alternative storage table with the extracted used capacity, and extracts the physical storage ID of the alternative mailbox storage device having the closest maximum capacity beyond the used capacity of the active mailbox storage device where the failure has occurred. . The maintenance operation device rewrites the physical storage ID of the active mailbox storage device 1300 in which the failure has occurred in the physical storage ID table 1220 of the user-to-mailbox management device 1200 with the extracted physical storage ID of the alternative mailbox storage device.

  As a result, the alternative mailbox storage device can be automatically selected, so that there is no need for the operator to specify it, and the operation can be simplified.

  In the above-described embodiment according to the present invention, a program or the like for executing the processing operation of the electronic mail server system is recorded as data on a recording medium (not shown) such as a magnetic disk or an optical disk of each device, The recorded data is read out and used to operate the electronic mail server system. As described above, data for operating the electronic mail server system according to the present invention is recorded on the recording medium, and the function of the electronic mail server system can be realized by installing the recording medium.

The figure which shows the structure of the electronic mail server system of this invention The figure explaining the electronic mail server system of this invention The figure which shows the operation | movement flow at the time of mail write / read / delete request processing in the mail transmission / reception request reception device The figure which shows the operation | movement flow at the time of the acquisition request acquisition of the mailbox ID and physical storage ID corresponding to the user ID in a user versus mailbox management apparatus The figure which shows the operation | movement flow at the time of working mailbox storage apparatus accepting the mailbox creation / deletion request from the entrance / exit management apparatus The figure which shows the operation | movement flow at the time of active mailbox storage apparatus receiving the write-in / read-out / deletion request | requirement of an email from the mail transmission / reception request reception apparatus. The figure which shows the operation | movement flow at the time of an alternative mailbox storage apparatus receiving the write-in / read-out / deletion request | requirement of an email from the mail transmission / reception request reception apparatus. The figure which shows the operation flow when the alternative mailbox storage device accepts the stay mail merge request from the maintenance operation device The figure which shows the operation flow when the alternative mailbox storage device accepts the alternative service post-processing request from the maintenance operation device The figure which shows the operation flow of allocation control of the entrance / exit management device The figure which shows the operation flow of deletion control of the entrance / exit management device The figure which shows the operation flow when the maintenance operation device accepts the switch request to the alternative mailbox storage device Diagram showing the operation flow when the maintenance operation device accepts a switch request to the active mailbox storage device

Explanation of symbols

1100 Mail transmission / reception request acceptance device 1200 User-to-mailbox management device 1210 Logical mailbox ID table 1220 Physical storage ID table 1300 Current mailbox storage device 1310 Current mailbox 1400 Alternative mailbox storage device 1410 Alternative mailbox 1500 Admission / rejection management device 1510 Physical mailbox ID table 1520 Physical storage allocation table 1600 Maintenance operation device 1700 Network 1800 User terminal 1900 Network

Claims (10)

A first table that manages a set of a user ID that is an identifier of an e-mail user, a mailbox ID that is an identifier of an active mailbox, and a logical ID of an active storage device;
A second table for managing a set of a logical ID of the active storage device and a physical ID of the active storage device;
Means for extracting a user ID from the received e-mail and searching the first table and the second table based on the extracted user ID to obtain the mailbox ID and the physical ID of the active storage device;
Means for requesting the physical storage device or the alternative storage device of the physical ID for the electronic mail processing by designating the mailbox ID;
A working storage device having a working mailbox with the mailbox ID and performing the requested email processing on the working mailbox;
Means for allocating an alternative storage device at the time of failure of the active storage device;
Means for rewriting the physical ID of the active storage device in which the failure has occurred on the second table with the physical ID of the alternative storage device;
An alternative storage device that generates an alternative mailbox having the mailbox ID and performs the requested email processing on the alternative mailbox;
An email server system comprising: A mail transmission / reception request receiving device, a user-to-mailbox management device, a working mailbox storage device, an alternative mailbox storage device, an entrance / exit management device, and a maintenance operation device,
The mail transmission / reception request accepting device is:
Means for receiving an email write / read / delete request;
Means for obtaining a mailbox ID and a physical storage ID corresponding to a user ID from the user-to-mailbox management device;
Means for designating the acquired mailbox ID to the active mailbox storage device or the alternative mailbox storage device having the acquired physical storage ID and making an e-mail write / read / delete request,
The user-to-mailbox management device
Logical mailbox ID table for registering correspondence between user ID which is identifier of electronic mail user, mailbox ID which is identifier of active mailbox and logical storage ID of active mailbox storage device, and logical storage of active mailbox storage device A physical storage ID table for registering the correspondence between the ID and the physical storage ID of the active mailbox storage device;
Means for receiving a user ID from the mail transmission / reception request accepting device;
Means for searching the logical mailbox ID table and the physical storage ID table to extract a mailbox ID and a physical storage ID corresponding to the received user ID;
Means for transmitting the extracted mailbox ID and physical storage ID to the mail transmission / reception request accepting device;
The working mailbox storage device
Holds the working mailbox identified by the mailbox ID,
Means for receiving an e-mail write / read / delete request designating a mailbox ID from the e-mail transmission / reception request receiving device;
Means for writing / reading / deleting an e-mail to / from a working mailbox having the designated mailbox ID;
The alternative mailbox storage device is:
Means for receiving an e-mail write / read / delete request designating a mailbox ID from the e-mail transmission / reception request receiving device;
Means for generating an alternative mailbox with the specified mailbox ID when there is no alternative mailbox with the specified mailbox ID;
Means for writing / reading / deleting an e-mail to / from an alternative mailbox having the designated mailbox ID;
The entrance / exit management device is:
The physical mailbox ID table for registering the correspondence between the user ID, the mailbox ID, and the physical storage ID of the current mailbox storage device, and the correspondence between the physical storage ID, the allocation number, and the allocation stop flag of the current mailbox storage device are registered. Hold the physical storage allocation table,
Means for searching the physical storage allocation table and selecting a working mailbox storage device when user membership is designated;
Means for transmitting a request to create a working mailbox having a designated mailbox ID to the selected working mailbox storage device;
Means for searching the physical mailbox ID table to specify a mailbox ID and a working mailbox storage device when a user withdrawal is specified, and specifying the deletion request of a working mailbox having the specified mailbox ID; Means for transmitting to the active mailbox storage device,
The maintenance operation device includes:
When the active mailbox storage device becomes a failure, the physical storage ID of the failed active mailbox storage device on the physical storage ID table in the user-to-mailbox management device is changed to that of the alternative mailbox storage device. Comprising means for rewriting the physical storage ID;
An e-mail server system characterized by that. The maintenance operation device includes:
Means for turning on an allocation stop flag corresponding to the active mailbox storage device on the physical storage allocation table when the active mailbox storage device becomes a failure;
The entrance / exit management device is:
Means for selecting a working mailbox storage device from working mailbox storage devices whose allocation stop flag is OFF;
The electronic mail server system according to claim 2, wherein: Including a mail transmission / reception request accepting device, a user-to-mailbox management device, a working mailbox storage device, an alternative mailbox storage device, a joining / leaving management device, and a maintenance operation device, and a user ID, a mailbox ID, and a working A logical mailbox ID table for registering the correspondence with the logical storage ID of the mailbox storage device, and a physical storage ID table for registering the correspondence between the logical storage ID of the current mailbox storage device and the physical storage ID of the current mailbox storage device. An email service method for an email server system comprising:
The mail transmission / reception request accepting device is:
Receive e-mail write / read / delete requests from user terminals,
Request the user-to-mailbox management apparatus for a mailbox ID and a physical storage ID corresponding to the received user ID;
The user-to-mailbox management device
Receiving an acquisition request for a mailbox ID and a physical storage ID corresponding to a user ID from the mail transmission / reception request accepting device;
Search the logical mailbox ID table by the user ID to identify the mailbox ID and logical storage ID;
Search the physical storage ID table with the specified logical storage ID to identify the physical storage ID,
Sending the mailbox ID and the physical storage ID to the mail transmission / reception request accepting device;
The mail transmission / reception request accepting device is:
Receiving a mailbox ID and a physical storage ID corresponding to the user ID from the user-to-mailbox management device;
Sending an e-mail write / read / delete request specifying the mailbox ID to the active mailbox storage device having the physical storage ID;
The working mailbox storage device
Receiving an email writing / reading / deleting request designating a mailbox ID from the email transmission / reception request accepting device;
Write / read / delete e-mail to / from the working mailbox with the specified mailbox ID
The maintenance operation device includes:
When notified that a failure has occurred in the working mailbox storage device,
Obtain a physical storage ID of an alternative mailbox storage device that replaces the active mailbox storage device in which the failure has occurred;
Rewriting the physical storage ID of the active mailbox storage device in which the failure has occurred in the physical storage ID table with the physical storage ID of the obtained alternative mailbox storage device;
E-mail service method electrostatic you, characterized in that. The mail transmission / reception request accepting device is:
Receive e-mail write / read / delete requests from user terminals,
Request the user-to-mailbox management apparatus for a mailbox ID and a physical storage ID corresponding to the received user ID;
The user-to-mailbox management device
Receiving an acquisition request for a mailbox ID and a physical storage ID corresponding to a user ID from the mail transmission / reception request accepting device;
Search the logical mailbox ID table by the user ID to identify the mailbox ID and logical storage ID;
Search the physical storage ID table with the specified logical storage ID to identify the physical storage ID,
Sending the mailbox ID and the physical storage ID to the mail transmission / reception request accepting device;
The mail transmission / reception request accepting device is:
Receiving a mailbox ID and a physical storage ID corresponding to the user ID from the user-to-mailbox management device;
Sending an email write / read / delete request specifying the mailbox ID to the alternative mailbox storage device having the physical storage ID,
The alternative mailbox storage device is:
Receiving an email writing / reading / deleting request designating a mailbox ID from the email transmission / reception request accepting device;
Write / read / delete emails to / from alternate mailboxes with specified mailbox IDs,
5. The electronic mail service method according to claim 4, wherein The alternative mailbox storage device is:
If there is no alternative mailbox with the specified mailbox ID,
Create an alternate mailbox with the specified mailbox ID,
The e-mail service method according to claim 5. A mail transmission / reception request accepting device, a user-to-mailbox management device, a working mailbox storage device, an alternative mailbox storage device 1400, an entrance / exit management device, and a maintenance operation device, and including a user ID and a mailbox ID An electronic mail service program for an electronic mail server system having a logical mailbox ID table for registering a correspondence with a logical storage ID and a physical storage ID table for registering a correspondence between a logical storage ID and a physical storage ID,
On the computer,
The mail transmission / reception request receiving device is
The function of receiving e-mail write / read / delete requests from the user terminal,
A function of requesting the user-to-mailbox management apparatus for a mailbox ID and a physical storage ID corresponding to the received user ID;
The user-to-mailbox management device is
A function of receiving a mailbox ID and physical storage ID acquisition request corresponding to a user ID from the mail transmission / reception request receiving device;
A function of searching the logical mailbox ID table by the user ID and specifying a mailbox ID and a logical storage ID;
A function of searching the physical storage ID table with the specified logical storage ID and specifying the physical storage ID;
A function of transmitting the mailbox ID and the physical storage ID to the mail transmission / reception request accepting device;
The mail transmission / reception request receiving device is
A function of receiving a mailbox ID and a physical storage ID corresponding to the user ID from the user-to-mailbox management apparatus;
A function of designating the mailbox ID to the active mailbox storage device having the physical storage ID and transmitting an e-mail write / read / delete request;
The working mailbox storage device is
A function of receiving an e-mail write / read / delete request designating a mailbox ID from the e-mail transmission / reception request accepting device;
A function for writing / reading / deleting an e-mail to / from a working mailbox having a specified mailbox ID,
The maintenance operation device is
When notified that a failure has occurred in the working mailbox storage device,
A function of obtaining a physical storage ID of an alternative mailbox storage device to replace the active mailbox storage device in which the failure has occurred;
A function of rewriting the physical storage ID of the active mailbox storage device in which the failure has occurred in the physical storage ID table with the physical storage ID of the obtained alternative mailbox storage device;
E-mail service program for realizing. The mail transmission / reception request receiving device is
The function of receiving e-mail write / read / delete requests from the user terminal,
A function of requesting the user-to-mailbox management apparatus for a mailbox ID and a physical storage ID corresponding to the received user ID;
The user-to-mailbox management device is
A function of receiving a mailbox ID and physical storage ID acquisition request corresponding to a user ID from the mail transmission / reception request receiving device;
A function of searching the logical mailbox ID table by the user ID and specifying a mailbox ID and a logical storage ID;
A function of searching the physical storage ID table with the specified logical storage ID and specifying the physical storage ID;
A function of transmitting the mailbox ID and the physical storage ID to the mail transmission / reception request accepting device;
The mail transmission / reception request receiving device is
A function of receiving a mailbox ID and a physical storage ID corresponding to the user ID from the user-to-mailbox management apparatus;
A function of designating the mailbox ID to an alternative mailbox storage device having the physical storage ID and transmitting an e-mail write / read / delete request;
The alternative mailbox storage device is
A function of receiving an e-mail write / read / delete request designating a mailbox ID from the e-mail transmission / reception request accepting device;
A function for writing / reading / deleting an email to / from an alternative mailbox having a specified mailbox ID,
The e-mail service program according to claim 7 for realizing the above. The alternative mailbox storage device is
If there is no alternative mailbox with the specified mailbox ID,
The ability to create an alternate mailbox for a given mailbox ID,
The e-mail service program according to claim 8 for realizing the above. A mailbox management server device for managing correspondence between an email user and a mailbox storing received emails,
A first table that manages a set of a user ID that is a user identifier, a mailbox ID that is a mailbox identifier, and a logical ID of a device in which the mailbox exists;
A second table for managing a set of a logical ID of a device in which a mailbox exists and a physical ID of a device in which a mailbox exists;
Means for receiving an acquisition request for a mailbox ID for a user ID and a physical ID of a device in which the mailbox exists;
Means for searching the first table and the second table to extract a mailbox ID for the user ID and a physical ID of a device in which the mailbox exists;
Means for transmitting the extracted mailbox ID and the physical ID of the device in which the mailbox exists to a request source;
Means for rewriting the physical ID of the device in which the mailbox on the second table exists with the physical ID of the device instructed from outside;
A server device comprising:

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