Apparatus and method for automatic transfer of data base information in response to load distribution among interconnected terminal stations
First Claim
1. A data-base management apparatus provided in each of a plurality of terminal stations associated with one another by communication lines in a distributed data-base communication system and respectively having data-base devices each of which stores respective data-base information, said terminal stations including a certain terminal station and other terminal stations, said data-base devices including a first data-base device internally arranged in said certain terminal station, and second data-base devices in said other terminal stations, said apparatus comprising:
- first monitor means for monitoring a first access load of said first data-base device of said certain terminal station, and for detecting whether the first access load exceeds a permissible level below which accessing to the data-base device does not overflow;
second monitor means for monitoring second access loads of said second data-base devices of said other terminal stations, and for detecting whether the second access loads exceed the permissible level; and
data-base distribution manager means connected to said first and second monitor means, for determining whether the first access load of said certain terminal station exceeds the permissible level, for specifying, when the first access load exceeds the permissible level, when at least one of the second access loads in said other terminal stations does not exceed the permissible level, and when a part of the data-base information of said first data-base device has a high access frequency, the external transfer of the part of the data base information with a high access frequency, for identifying one of said other terminal stations most frequently using said part of the data-base information with a high access frequency, for transferring said part of the data-base information to the identified one of said other terminal stations which accesses said part most frequently when the second access load of the identified one of said other terminal stations is less than the permissible level, and for, when the second access load of said identified one of said terminal stations is not below said permissible level, transferring said part of the data-base information to one of said other terminal stations whose second access load is lightest among the remaining other terminal stations.
1 Assignment
0 Petitions
Accused Products
Abstract
A distributed data-base communication network system includes a plurality of terminal stations which respectively contain data-base devices and which are associated with one another by means of data communication lines. A data-base management apparatus is provided in each of these stations and includes an internal load monitor device for monitoring the accessing load of the internal data-base device of the internal station and an external load monitor device for monitoring the accessing loads of the data-base devices of the external terminal stations. A data-base load distribution management device is connected to the monitor devices, and automatically transfers at least part of the data-base information of the internal data-base device to a selected one of the external terminal stations when the internal data-base accessing load has exceeded the maximum permissible level, thus enhancing the uniformity of distribution of the data-base load of the communication network.
72 Citations
17 Claims
-
1. A data-base management apparatus provided in each of a plurality of terminal stations associated with one another by communication lines in a distributed data-base communication system and respectively having data-base devices each of which stores respective data-base information, said terminal stations including a certain terminal station and other terminal stations, said data-base devices including a first data-base device internally arranged in said certain terminal station, and second data-base devices in said other terminal stations, said apparatus comprising:
-
first monitor means for monitoring a first access load of said first data-base device of said certain terminal station, and for detecting whether the first access load exceeds a permissible level below which accessing to the data-base device does not overflow; second monitor means for monitoring second access loads of said second data-base devices of said other terminal stations, and for detecting whether the second access loads exceed the permissible level; and data-base distribution manager means connected to said first and second monitor means, for determining whether the first access load of said certain terminal station exceeds the permissible level, for specifying, when the first access load exceeds the permissible level, when at least one of the second access loads in said other terminal stations does not exceed the permissible level, and when a part of the data-base information of said first data-base device has a high access frequency, the external transfer of the part of the data base information with a high access frequency, for identifying one of said other terminal stations most frequently using said part of the data-base information with a high access frequency, for transferring said part of the data-base information to the identified one of said other terminal stations which accesses said part most frequently when the second access load of the identified one of said other terminal stations is less than the permissible level, and for, when the second access load of said identified one of said terminal stations is not below said permissible level, transferring said part of the data-base information to one of said other terminal stations whose second access load is lightest among the remaining other terminal stations. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A distributed data-base communication system comprising:
-
a plurality of terminal stations including respective data-base devices; communication lines for connecting said stations to one another so as to permit communication of any one of said terminal stations with any other thereof; and data-base load-distributing management devices provided respectively in each of said terminal stations, each of said data-base load-distributing management devices comprising, (i) internal load monitor means for monitoring an internal data-base access load resulting from data requests made of the respective terminal station to which said internal load monitor means belongs, and for detecting whether the internal access load exceeds a permissible level below which accessing to the data-base device does not overflow, (ii) external load monitor means for monitoring data-base access loads resulting from data requests made of others of said terminal stations, and for detecting whether each of the access loads of said others of said terminal stations exceeds the permissible level; and (iii) load distribution management means responsive to said internal load monitor means and said external load monitor means, for determining whether a part of the data-base information stored in the data-base device of one of the terminal stations has a high access frequency and is accessed by at least one of said others of said terminal stations, for specifying when the data-base access load of said one terminal station exceeds the permissible level, when the data-base access load of at least one of the others of the terminal stations does not exceed the permissible level, and when a part of the access load of the one terminal station has a high access frequency the external transfer of the part of the data-base information with a high access load, for identifying one of the others of said terminal station most frequently using the part of the data-base information with a high access frequency, for transferring the part of the data-base information with a high access frequency to the identified one of the others of the terminal stations identified as most frequently using the part of the data-base information when the access load of the identified one of said terminal stations does not exceed the permissible level, and for transferring the part of the data-base information with a high access frequency to another one of the others of said terminal station when the access load of the identified one of said terminal station is not less than the permissible level. - View Dependent Claims (9, 10)
-
-
11. A method for automatically distributing data-base information between data-base devices of a plurality of terminal stations associated with one another by means of communication lines in a distributed data-base communication system, said method comprising the steps of:
-
monitoring a first data-base access load of a certain terminal station to detect whether the first data-base access load exceeds a permissible level below which accessing to the data-base device does not overflow; monitoring second data-base access loads of others of said terminal stations to detect whether each of the second data-base access loads of said others of said terminal stations exceeds the permissible level; determining whether a part of the data-base information of said certain terminal station has a high access frequency; specifying, when said first data-base access load exceeds the permissible level, when the second data-base access load of at least one of said others of said terminal stations does not exceed the permissible level, and when a part of the data-base information of said certain terminal station has a high access frequency, the external transfer of the part of the data-base information with a high access frequency; identifying one of said others of said terminal stations most frequently using said part of the data-base information with a high access frequency; transferring the part of the data-base information with a high access frequency to the identified one of said others of said terminal stations identified in said identifying step when the second data-base access load of said identified one of said others of said terminal stations is less than the permissible level; and transferring, when the second access load of said identified one is not less than the permissible level, said part of the data-base information with a high access frequency to another one of said others of said terminal stations whose second data-base access load is most light among the remaining others of said terminal stations. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
Specification