JP2003242110A - Access control device, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make efficiently allocatable the accesses to a Web server when accesses are concentrated to the Web server. <P>SOLUTION: When accesses are made from a plurality of users to the Web server 3, accesses to the Web server 3 are controlled in this device. It is mad to have a user information memory data base 11 to memorize priority information indicating priority of each user in accessing to the Web server 3, and an access order registering part 16 to allot an access order to the Web server 3 in the order of priority set to each user by referring to the priority information in the user information data base 11 when the user is unable to immediately access to the Web server 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for controlling user access to a web server.

[0002]

2. Description of the Related Art Today, with the development of the Internet, W
Various contents are provided on the eb server. Depending on the content provided by such a Web server, the user's access is concentrated on a specific Web server, and thus a load balancer is provided. Then, with this load balancer, W
The number of accesses to the eb server is monitored, and when the allowable access amount to this Web server is exceeded, the users who have accessed the server are notified that they should wait for a while before making an access, and the access is concentrated. It is possible to prevent the down of the Web server.

[0003]

However, the user who accesses the Web server has no idea what the load condition or failure condition of the server is and when it will be resolved. When that happened, I wasn't sure if I could access the Web server, which caused unnecessary frustration to the user. In addition, many users, for example, perform a reloading (reloading) when the message "currently busy" is returned, but when this is repeated many times, an access state such as a so-called DoS attack is generated, As a result, there is a problem that a further high load state is caused, and in some cases, the system goes down.

In addition, since the conventional Web servers handle users under the same conditions regardless of whether they are good customers or not, even if they are good customers, they cannot access the Web server for a long time like other users. Sometimes continued. Therefore, for example, EC (Electronic Com
(merce) sites and the like have a problem in that if the website cannot be accessed, the user will move to another EC site and lose good customers.

Further, for example, W for ticket reservations for popular games and concerts, safety confirmation in disasters and emergencies, etc.
In an eb server or the like, concentrated access may be made for a period of time, and there is an increasing need to prevent system down due to such concentrated access.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to enable a user to efficiently access a Web server.

[0007]

In order to solve the above problems, an access control device according to the present invention is provided with a predetermined web.
A device that controls access to the Web server when a plurality of users access the server, and sets priority information indicating the priority of each user when accessing the Web server. When the user cannot immediately access the stored user information storage unit and the Web server, the Web server is referred to in the descending order of the priority set for the user by referring to the priority information of the user information storage unit. And an access assigning unit that assigns an access order to the server. As a result, a user with a high priority can preferentially access the Web server, and an appropriate service can be provided according to the priority of the user.

[0008] The access assigning means sets a vacant time at which access to the Web server is possible at a predetermined interval, and when a user having a predetermined priority issues an access request, the user is assigned to the above-mentioned user. It may be assigned to a free time.

Further, when the same user makes a plurality of access requests, the access allocating means may invalidate the access order allocated based on the access request made earlier by the user. As a result, the user suffers the disadvantage that the access sequence becomes slower each time the user reloads, so that it may be possible to prevent the occurrence and continuation of a high load state on the Web server due to the repeated reloading of the user.

Further, when the same user makes a plurality of access requests, the access assigning means refers to the priority of the user in the user information storage means, and has a priority higher than a predetermined priority. In the case of a user having the following, the access order that is earlier than the access order previously assigned to the user may be assigned. As a result, a user having a higher priority than the predetermined priority can preferentially access the Web server, and, for example, can provide a preferential service to a good customer or the like.

Further, the access allocation means is the We
The predetermined notification means may be instructed to estimate the time when the server can be accessed and notify the user of the estimated time information. Thereby, the user can predict the time when the Web server can be accessed, and the user's dissatisfaction and anxiety that he / she cannot access the Web server can be alleviated.

Further, from the access history information for the Web server, access statistical information including failure cause information indicating a reason why the Web server cannot be accessed and inaccessible time information for each failure cause information that cannot be accessed. It further has an access statistics calculation means to create,
The access assigning unit may estimate the time during which the Web server can be accessed, based on the failure cause information calculated by the access statistics calculating unit. This makes it possible to estimate the accessible time based on the statistical data.

If there is access history information indicating that the access cannot be made based on the same cause of failure within a predetermined time, the access statistics calculating means sums the times when the access cannot be made. The above W
It may be set to a time when the eb server could not be accessed. As a result, even when the cause of failure occurs intermittently, it can be treated as one continuous occurrence of failure.

The access allocating means identifies the cause of the access failure that cannot access the Web server, and estimates the time when the Web server can be accessed based on the past duration of the access failure cause. May be. In addition, the access allocation means,
Based on either the duration of the access failure cause for each day of the week on the Web server or the duration of the access failure cause for each predetermined time period, the time during which the Web server can be accessed can be estimated. May be. This makes it possible to more accurately predict the date and time when the Web server can be accessed.

When access to the Web server becomes possible, the user is notified that access is possible, or the user is sent to the W
You may make it further have an access permission means to access an eb server. As a result, the user can smoothly access the Web server when the Web server becomes accessible.
You can access the server.

A computer program according to the present invention is a computer program for causing a computer to function as a device for controlling access from a user to a predetermined Web server, and allows the computer to access the Web server. The process of storing the priority information indicating the priority of each user in the user information storage means, and the priority information of the user information storage means when the Web server cannot be accessed immediately, And a process of assigning an access order to the Web server in descending order of the priority set for.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a system using an access control device according to the present invention. In FIG. 1, in the present embodiment, the user terminal 4 can be connected to the Web server 3 via the load balancer 2 and sorry server 1 via the Internet.

The user terminal 4 is a terminal used by a user who accesses the Web server 3 or the like. The user terminal 4 is composed of a computer and can be connected to the Internet by a predetermined browser, so that the website provided by the web server 3 can be accessed. The web server 3 is composed of a computer and is a server that provides a web site for transmitting predetermined contents and the like to the user. This W
The eb server 3 may provide, for example, a shopping site, a site that accepts reservations for tickets, or a site that accepts safety information at the time of an emergency disaster on the Internet, and the content to be provided is arbitrary. The load balancer 2 monitors the load state from the number of accesses from the user to the Web server 3, and when the number of accesses exceeds a predetermined number, the date and time when a high load occurs on the sorry server 1,
It is possible to notify the high load occurrence information including the cause information and the like. The load balancer 2 can also create access log data representing the number of accesses to the Web server 3 according to the time zone or the day of the week.

The sorry server 1 allows the user to immediately
b A server that sends a predetermined message to the user terminal 4 when the server 3 cannot be accessed. This sorry server 1 is composed of a computer,
By a CPU (Central Processing Unit), a computer program executed by the CPU, an internal memory such as RAM or ROM, or an external storage device such as a hard disk device,
The functional blocks shown in FIG. 1 are configured. The functional blocks shown in FIG. 1 are a user information database 11, an access permission order information database 12, an access statistics database 13, a communication control unit 14, an access statistics calculation unit 15, an access order registration unit 16, a message creation unit 17, and an access permission. It is composed of a determination unit 18.

The user information database 11 is a storage unit that makes a database of information about users. As shown in FIG. 2, for example, the user information database 11 can store a user name, a password as user authentication information, a priority, and a user's mail address. The priority is information indicating the priority of the user when the user accesses each Web server 3, and for example, to the operator who operates a predetermined Web site, how good the user is the customer. It is determined by whether or not there is.

The access permission order information database 12 is
The storage unit is a database of information such as access permission time based on the access order assigned to the user. In this access permission order information database 12,
For example, as shown in FIG. 3, the user name, the priority of the user, the access date and time indicating the date and time when the user requests access to the Web server 3, and the access permission date and time indicating the accessible date and time assigned to the user. You can remember.

The access statistics database 13 is a Web
The storage unit is a database of failure information that has occurred in the server 3. In the access statistics database 13, for example, as shown in FIG. 4, high load occurrence date / time, high load release date / time, continuation time, and type code can be stored. High load occurrence date is We
b The date and time when a high load occurs on the server 3, the high load release date and time indicate the date and time when the high load is resolved, and the duration indicates the duration of the high load state. The type code is a code for identifying the cause of the high-load failure that has occurred. In the present embodiment, for example, "0" is given when normal processing is performed, and "1x" is given when a load occurs.
x ”,“ 2xx ”when an error occurs,
The cause can be identified by the digit (for example,
If it is "115", it means that the CPU usage rate of the database server has reached 100%).

The communication control unit 14 controls the communication interface to perform transmission / reception processing of predetermined data between the load balancer 2 and the user terminal 4. Access statistics calculator 1
5 refers to the access statistics database 13
From the access history information for the server 3, access statistical information including a type code indicating a cause of failure in which the Web server 3 cannot be accessed, and an inaccessible time (access-disabled time) for each type of different code (cause of failure) Process to create. When creating the access statistical information, the access statistics calculating unit 15 sums up the inaccessible times when there is a time in which the same type code cannot be accessed within a predetermined time. The time may be the time when the Web server 3 cannot be accessed.

The access order registration unit 16 is used by the Web server 3
When a plurality of users are accessed for, the priority information of each user in the user information storage database 11 is referred to, and the processing of assigning the access permission date and time to the Web server 3 in descending order of priority is executed. It can be carried out. In this case, for example, the access order registration unit 16 sets the access free time to the Web server 3 at a predetermined interval in advance, and when there is an access request from a user having a predetermined priority, The free time may be set as the access permission time of the user. Also,
When the same user repeatedly makes multiple access requests, the access order registration unit 16 can treat the access permission date and time assigned based on the access request made earlier by the user as invalid.

Further, the access order registration unit 16 performs a process of estimating the access permission date and time when the user can access the Web server 3 immediately when the user cannot access the Web server 3 immediately. In this estimation process, for example, the access order registration unit 16 identifies the type code of the access failure cause that is inaccessible to the Web server 3, and based on the average value of the past durations of the failures corresponding to the type code. You may estimate. Also, for example,
The access order registration unit 16 may make an estimation based on either the duration of the access failure cause for each day of the week for the Web server 3 or the duration of the access failure cause for each time zone.

The message creation unit 17 creates message information for the user based on the information such as the access permission date and time of the user determined by the access order registration unit 16.
This message is, for example, HTML (Hyper Te
It is also possible to create a message in xt Markup Language) prompting the user to access the Web server 3 again at a predetermined date and time.

The access permission judging unit 18 notifies the user terminal 4 that the high load condition is resolved and the Web server 3 can be accessed. In this notification, for example, the access permission determination unit 18 may notify that the Web server 3 can be accessed by e-mail based on the user's mail address stored in the user information database 11. . In addition, the access permission determination unit 18
When the access to the web server 3 becomes possible, the browser may instruct the user terminal 4 to automatically connect to the predetermined web server 3.

Next, the access control method according to this embodiment will be described with reference to the drawings. First, the process of creating the access statistical information from the access log data to the Web server 3 will be described with reference to FIG. In FIG. 5, the access statistic calculation unit 15 controls the load balancer 2 to the Web server 3 via the communication control unit 14.
The access log data for is acquired (S11). At this time, the access log data acquired from the load balancer 2 includes, for example, data such as access date / time, distribution destination IP address, type code, and status flag indicating occurrence / cancellation of status.

When the access log data is acquired, the access statistic calculation unit 15 extracts records in the access log data other than the record having the type code "normal" (type code "0" in this embodiment) ( S1
2). Thus, when accessing the Web server 3, some kind of failure (for example, load occurrence, error, etc.) occurs, and the log data including the type code that cannot immediately access the Web server 3 is extracted.

Of the extracted log data, the access statistic calculation unit 15 extracts, as unregistered case data, log data having the same type code and a pair of status flags “occurred” and “released”. Yes (S13). A case registration process described below is performed on the extracted unregistered case data, and the unregistered case data is registered in the access statistical database 13 (S14). When the case registration process is completed, the access statistic calculation unit 15 determines whether or not there is unregistered case data for which the case registration process has not been performed (S15). As a result of the determination, when there is unregistered case data, the process returns to the above S13 and the above process is repeated. Further, as a result of the determination, if there is no unregistered case data, the process ends.

Next, the case registration process described above will be described with reference to FIGS. 6 and 7. In the present embodiment, FIG.
As schematically shown in FIG. 3, a case where case A and case C are already registered in the access statistical database 13 and unregistered cases of case B and case D are newly registered will be described as an example. In addition, "0" in FIG. 7 represents occurrence of a high load state, and "1" represents cancellation of the high load state. First, the access statistic calculation unit 15 extracts one record (case B or case D in the example of FIG. 7) from the unregistered case data in the process of S13 described above (S21).
The access statistic calculation unit 15 determines whether or not the type code is the same as the extracted unregistered case data in the access statistic database 13 and the difference between the high load occurrence date and time and the resolution date and time is within a predetermined time. Yes (S22).

As a result of the discrimination, the access statistics database 1
When it is determined that the corresponding record exists in 3, the access statistic calculation unit 15 updates the high load elimination date and time of the corresponding record on the access statistics database 13 to the high load elimination date and time of the unregistered case ( S23). In the example of FIG. 7, since the high load start date and time of Case A is within a predetermined time (for example, 5 minutes) with respect to Case B, it is determined that Case A is the corresponding record, and the high load resolution date and time of Case A is It is updated at the high load elimination date and time of case B.

Further, the access statistic calculating unit 15 calculates the difference between the high load occurrence date and time and the high load elimination date and time (in the example of FIG. 7, the high load occurrence date and time of case A and the high load release date and time of case B) of the corresponding record. Then, the duration is calculated (S24).
Then, the access statistic calculation unit 15 updates the duration of the access statistic database 13 based on the calculated duration (S25), and ends the process.

Further, in the above-mentioned processing of S22, when it is determined that the corresponding record does not exist, this unregistered case (in the example of FIG. 7, the case of exceeding the predetermined time of 5 minutes) D) is additionally stored in the access statistics database 13 (S26), and the process ends.

Next, the processing when the Web server 3 cannot be immediately accessed will be described with reference to FIG. In FIG. 8, when the Web server 3 is in a high load state and the load balancer 2 notifies the high load occurrence information,
The access order registration unit 16 acquires the high load occurrence date and time and the high load occurrence type code notified from the load balancer 2 (S31). Upon receiving the access request from the user, the access order registration unit 16 identifies the user name of the user included in the access request and the access date and time (S).
32).

The access order registration unit 16 refers to the user information database 11 and extracts the priority of the user (S33). The access order registration unit 16 also refers to the access statistics database 13 to estimate the date and time when the high load state is released (S34). As this estimation process, for example, the access order registration unit 16 estimates the time when the high load state is released based on the average value of the continuation times of the same type code that has occurred this time and is stored in the access statistical database 13. You may. Further, the access order registration unit 16 estimates the time when the high load is released from the average value of the continuation time of the type code of the same failure that occurred in the same time zone or day of the week stored in the access statistics database 13. Good.

Further, the access order registration unit 16 determines whether or not there is already a record of the user in the access permission order information database 12 (S35). As a result of the determination,
If there is already a record of the same user in the access permission order information database 12, it is assumed that the user has reloaded and repeatedly accessed, and the access permission of the user previously stored in the access permission order information database 12. Delete the date and time to make it invalid (S3
6).

After the record is deleted in the process of S36, or when it is determined in the process of S35 that there is no record of the user, the access order registration unit 16
Calculates the access permission date and time of the Web server 3 for the user according to the access date and the priority of the user (S37). As this processing, for example, FIG.
As schematically shown in FIG. 3, a free time may be secured in advance at a predetermined interval, and when a user having a predetermined priority or higher is accessing, the free time may be allocated. In addition, when there are users (for example, user B and user C) for whom the access permission date and time have already been set, for example, a user (for example, user A) having a higher priority than the already set user is The free time may be allocated before that, and an appropriate method may be used for this allocation according to the priority of the user and the access date and time.

When the allocation is completed, the access order registration unit 16
Stores the user name and priority, access date and time, and assigned access permission date and time in the access permission order information database 12 (S38).

Next, in FIG. 9, the message creating unit 17 acquires the user name, access date and time, and access permission date and time to which the access permission date and time are assigned from the access order registration unit 16 (S39), and the corresponding user name and access date and time. The standby request information for the user is created from the access permission date and time (S40). FIG. 11 shows an example of this waiting request information. As shown in FIG. 11, the wait request information for the user may be, for example, how many minutes should be waited, and depending on the website, the access permission determination unit 18 may be a temporary reception that sends an email when it is the user's turn. The temporary receipt number may be notified as shown in FIG. Then, the message creation unit 17 notifies the user terminal 4 of the generated standby request information via the communication control unit 14 (S41), and ends the process.

Next, the processing when the high load condition is resolved will be described with reference to FIG. In FIG. 13, the access permission determination unit 18 performs a determination process of whether or not there is a notification from the load balancer 2 that the high load state has been released,
The process is repeated until this notification is received (S51). In this state,
When the notification that the high load state has been released is received from the load balancer 2 (S52), the access permission determination unit 18 refers to the access permission database 13 and finds a record whose access permission date and time has already passed. It is determined whether or not (S53).

As a result of the determination, when there is no record whose access permission date and time has passed, the access permission determination unit 18
Ends the processing, assuming that there is no record to which access is permitted. If there is a record that has passed the access permission date and time, the access permission determination unit 18 follows the access permission date and time stored in the access permission order information database 12, for example, as shown in FIG.
The user is notified of the access permission notification including the URL or the like for accessing the predetermined website by e-mail (S54), and the process is terminated.

As described above, according to the above-described embodiment, the access order registration unit 16 preferentially assigns the access order to the users having a high priority order. You can get preferential treatment. As a result, for example, it becomes possible to provide a service by prioritizing a good customer or the like to connect to the Web server 3, so that the good customer can quickly access the desired Web server 3 without waiting for a long time, and the service can be provided. Will be able to provide.

Further, when the same user makes access requests a plurality of times, the access order registration unit 16 deletes all the access requests made by the user as invalid, so that the access order registration unit 16 reloads each time. Since the access sequence of the user is delayed, which is a disadvantageous condition for the user, it is possible to prevent the load on the Web server 3 from being repeatedly loaded by the user.

When the user cannot immediately access the Web server 3, the access order registration unit 16
However, since the date and time when the Web server 3 can be accessed is estimated and notified to the user, the user can know when to access the Web server 3 and how long to wait. it can. As a result, the user's dissatisfaction, anxiety, distrust, and the like who do not know when the Web server 3 can be accessed can be eliminated.

Further, the access order registration unit 16 estimates the accessible date and time based on the past record information stored in the access statistics database 13 when determining the accessible date and time. Can be appropriately estimated based on past performance.

The access order registration unit 16 determines the time when the Web server 3 can be accessed based on either the duration of the high load state for each day of the week or the duration of the high load state for each time zone. By performing the estimation, it is possible to appropriately estimate the time when the Web server 3 can be accessed for each day of the week and each time zone.

In addition, the access permission judging unit 18
When the server 3 can be accessed, the user is notified that the server 3 can be accessed, so that the user can access the Web server 3. You can know in a timely manner. The access permission determining unit 18 may allow the user to access the Web server 3 when the Web server 3 is accessible.
As a result, the user can automatically access the desired Web server 3 without any special processing.

Access from the access history information for the Web server 3 by the access statistic calculation unit 15 including a type code indicating the reason why the Web server 3 cannot be accessed, and continuation time information for each type of code that cannot be accessed. The statistical information is created and the access order registration unit 16
Since the time during which the Web server 3 can be accessed is estimated based on the type code of the access statistical information, it is possible to estimate an appropriate time for each type of code.

If there is access history information indicating that the access could not be made for the same reason within the predetermined time, the access statistic calculation unit 15 calculates the time obtained by adding up the access inaccessible times. Since the time information cannot be set, even when a certain failure occurs intermittently, the Web server 3 can be treated as being inaccessible.

In the above embodiment, when the same user makes access requests a plurality of times, the previously assigned access order is invalidated. However, instead of this, for example, the access order is changed. When the registration unit 16 makes a plurality of access requests from the same user, the registration unit 16 refers to the priority of the user stored in the user information database 11, and determines that the user has a higher priority than the predetermined priority. In some cases, an access order that is earlier than the previously assigned access order may be assigned to the user. As a result, the user having a higher priority than the predetermined priority can preferentially access the Web server 3, and, for example, can provide a preferential service to a good customer or the like.

The sorry server 1 according to the present embodiment is
It may be a dedicated device or may be realized by using a general-purpose computer and computer program. When it is realized by using a general-purpose computer, for example, from a computer program for executing the above-mentioned operation on the general-purpose computer or a computer-readable medium (FD, CD-ROM, etc.) storing the computer program. You may make it comprise each apparatus which performs the above-mentioned process by installing a computer program. When the OS (Operating System) shares the above-mentioned functions or when the OS and the application program are jointly implemented, only a part other than the OS is stored as a computer program, and the computer program is stored in a computer-readable medium. You may.

It is also possible to superimpose each computer program for the sorry server 1 on a carrier wave and distribute it via a communication network. For example, the program may be posted on a bulletin board (BBS) of a communication network and distributed via the network.
Then, this computer program may be started up and executed in the same manner as other application programs under the control of the OS to execute the above-mentioned processing.

[0054]

According to the present invention, a user can efficiently We
b The server can be accessed.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an overall configuration of an embodiment according to the present invention.

FIG. 2 is a diagram showing an example of data stored in a user information database according to the present embodiment.

FIG. 3 is a diagram showing an example of data stored in an access permission order information database according to the present embodiment.

FIG. 4 is a diagram showing an example of data stored in an access statistics database according to the present embodiment.

FIG. 5 is a processing flow showing a processing flow when creating access statistical information according to the present embodiment.

FIG. 6 is a processing flow showing a flow of case registration processing according to the present embodiment.

FIG. 7 is a schematic diagram showing an example of case registration processing according to the present embodiment.

FIG. 8 is a processing flow showing a processing flow when the number of accesses to the Web server according to the present embodiment exceeds a predetermined amount.

FIG. 9 is another processing flow showing a processing flow when the number of accesses to the Web server according to the present embodiment exceeds a predetermined amount.

FIG. 10 is a schematic diagram showing an example of determining an access permission date and time according to the present embodiment.

FIG. 11 is a diagram showing an example of a waiting request message for the user according to the present embodiment.

FIG. 12 is a diagram showing another example of a waiting request message for the user according to the present embodiment.

FIG. 13 is a process flow showing a process when the high load state on the Web server according to the present embodiment is released.

FIG. 14 is a Web page for a user according to the present embodiment.
The figure which showed an example at the time of notifying that access to a page became possible.

[Explanation of symbols]

1 sorry server 2 load balancer 3 Web server 4 user terminals 11 User information database 12 Access permission order information database 13 Access statistics database 14 Communication control unit 15 Access Statistics Calculation Department 16 Access order registration section 17 Message Creation Department 18 Access permission judgment section

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ken Kageyama             Stock Exchange, 3-3 Toyosu 3-chome, Koto-ku, Tokyo             Company NTT Data (72) Inventor Yusaku Nakajima             Stock Exchange, 3-3 Toyosu 3-chome, Koto-ku, Tokyo             Company NTT Data F-term (reference) 5B085 BA06 BG02 BG07

Claims (11)

[Claims] 1. A device for controlling access to the Web server when a predetermined Web server is accessed by a plurality of users, the device being for each user when accessing the Web server. A user information storage unit that stores priority information indicating a priority order, and is set for the user by referring to the priority information of the user information storage unit when the user cannot immediately access the Web server. An access control device comprising: an access assigning unit that assigns an access order to the Web server in descending order of priority. 2. The access allocating means sets a vacant time at which access to the Web server is possible at predetermined intervals, and when an access request is made from a user having a predetermined priority, the user is accessed. The access control device according to claim 1, wherein is assigned to the free time. 3. The access allocating means invalidates the access order allocated based on the access request made earlier by the user when the same user makes a plurality of access requests. Alternatively, the access control device according to item 2. 4. The access assigning means refers to the priority of the user in the user information storage means when a plurality of access requests are made by the same user, and the priority is higher than a predetermined priority. The access control device according to claim 1 or 2, wherein, when the user has the following, an access order earlier than the access order assigned last time is assigned to the user. 5. The access allocating means instructs a predetermined notifying means to estimate a time when the web server can be accessed and notify the user of the estimated time information. The access control device according to any one of claims 1 to 4. 6. From the access history information to the Web server, access statistical information including failure cause information indicating a reason why the Web server cannot be accessed and inaccessible time information that cannot be accessed for each failure cause information. The access statistic calculating means to create is further provided, The said access allocation means estimates the time when it becomes accessible to the said Web server based on the failure cause information which the said access statistic calculating means calculated. Access control device. 7. The access statistic calculating means, if there is access history information in which a state of being inaccessible occurs based on the same cause of failure within a predetermined time, adds up the inaccessible times. The access control device according to claim 6, wherein the time taken is a time when the Web server cannot be accessed. 8. The access assigning unit identifies the cause of an access failure that cannot access the Web server, and estimates the time when the Web server can be accessed based on the past duration of the cause of the access failure. The access control device according to any one of claims 5 to 7. 9. The access assigning means, based on either the duration of the access failure cause for each day of the week for the Web server or the duration of the access failure cause for each predetermined time period, to the Web server. The access control device according to any one of claims 5 to 7, which estimates a time during which access is possible. 10. When the access to the Web server is enabled, the user is notified that the access is enabled, or the access permission for the user to access the Web server. The access control device according to any one of claims 5 to 7, further comprising means. 11. A computer program for causing a computer to function as a device for controlling access from a user to a predetermined Web server, the computer program of each user when accessing the Web server to the computer. The process of storing the priority information indicating the priority order in the user information storage means, and when the Web server cannot be immediately accessed,
A computer program for executing a process of referring to the priority information of the user information storage means and allocating an access sequence to the Web server in descending order of priority set for the user.