Information system

1. An information system comprising a data center having a center file server, and multiple sites each having a local file server storing user files of multiple users, wherein

the local file server is configured to calculate a predicted arrival time of a user having logged off from the local file server to the multiple sites;

based on the predicted arrival time, determine a priority of the user files to be replicated to the center file server; and

replicate the user files to the center file server in accordance with the priority, wherein

the local file server is configured to determine whether the user is approaching its own site based on the location information of its own site where the local file server is located and the location information of the user at multiple points of time; and

download the user files of the user determined to be approaching its own site from the center file server, before the user logs in to the local file server, and

wherein

the local file server is configured to store multiple information of time when the user has been determined to be approaching its own site, associated with the user information, in an approach determination history table;

store multiple information of time in which the user has logged into the local file server, associated with the user information, in a login date and time table;

use the approach determination history table and the login date and time table to calculate a login probability in accordance with the following calculation:

(number of times of login to the local file server of the user determined to be approaching its own site)/(number of times that the user had been determined to be approaching its own site); and

based on the login probability, calculate an upper limit value of download of data of the respective users.

2. The information system according to claim 1 , wherein

the local file server is configured to determine a user file having a high priority, in order from the user file of a user having the shortest predicted arrival time.

3. The information system according to claim 1 , wherein

after replication to the center file server has been performed, the local file server is configured to perform stubbing of a file having been replicated to the center file server.

4. The information system according to claim 1 , wherein

based on location information of the multiple sites and location information of the user at multiple points of time, the local file server is configured to calculate the predicted arrival time to the multiple sites.

5. The information system according to claim 4 , wherein

the location information of the user is a location information transmitted periodically from a mobile terminal possessed by the user.

6. The information system according to claim 5 , wherein

when the center file server receives a location information periodically transmitted from the mobile terminal possessed by the user, the center file server is configured to store the location information together with the user information and a reception time of the location information; and wherein

the local file server is configured to acquire multiple sets of information of the location information and the reception time of the location information from the center file server.

7. The information system according to claim 1 , wherein

the local file server is configured to calculate a predicted arrival time of the respective users to its own site based on a location information of its own site and a location information of the respective users at the multiple points of time, and

determine that a user whose predicted arrival time is equal to or below a given threshold is approaching its own site.