Information distribution system and load balancing method thereof

• US 20020091786A1
• Filed: 11/01/2001
• Published: 07/11/2002
• Est. Priority Date: 11/01/2000
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Akio, Yamaguchi, Nobuhiro, Ueno, Hitoshi
• Application Number:
  US09/985,111
• Publication Number:
  US 20020091786A1
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: G06F 2209/508 Monitor
• CPC Class Codes: G06F 2213/0038 System on Chip
• CPC Class Codes: G06F 9/5083 Techniques for rebalancing the load in a distributed system

Abstract

In a logical partitioning system, a Web server program is executed on each of several logical partitions, the load on each of the logical partitions is monitored, and when a logical partition is overloaded, data being distributed by the logical partition is automatically switched for distribution by another logical partition that has spare capacity to accommodate the load, whereby load balancing is carried out.

Claims

1. An information distribution system comprising:

a plurality of information distribution units that distribute information as requested from users, which include one or more information distribution unit groups having at least two information distribution units capable of distributing the same information;

means for monitoring load on each of said information distribution units; and

means for transferring information held for distribution by an information distribution unit that is overloaded because its load exceeds a predetermined load to one of the information distribution units of said information distribution unit group, to enable the distribution of the same information as distributed by said overloaded information distribution unit.

4. The information distribution system according to claim 1, wherein said load is determined from the number of accesses from users in a certain time interval.

5. The information distribution system according to claim 1, further comprising means of storing, wherein if an information distribution unit is overloaded because its load exceeds a predetermined load and there is no information distribution unit with spare capacity for accommodating the load, said means for storing stores information that can be distributed by said overloaded information distribution unit in an information distribution unit that has not distributed any information so far, thereby making it possible to distribute the information to the users.

2. An information distribution system comprising:

a plurality of logical partitions that distribute information requested from users;

a shared memory that is shared by said plurality of logical partitions;

means for monitoring the load on said logical partitions; and

means for transferring information that can be distributed by an information distribution unit that is overloaded because its load exceeds a predetermined load to a more lightly loaded logical partition via said shared memory.

6. The information distribution system according to claim 2, further comprising means for storing, wherein if a logical partition is overloaded because its load exceeds a predetermined load and there is no logical partition with spare capacity for accommodating the load, said means for storing stores information that can be distributed by said overloaded information distribution unit in an information distribution unit that has not distributed any information so far, thereby making it possible to distribute the information to the users.

3. An information distribution system comprising:

a plurality of logical partitions that distribute information requested from users and include one or more logical partition groups having at least two logical partitions that can distribute the same information;

a shared memory that is shared among said plurality of logical partitions;

means for monitoring load on each of said plurality of logical partitions; and

means for transferring information held for distribution by an information distribution unit that is overloaded because its load exceeds a predetermined load to a logical partition with spare capacity for accommodating the load via said shared memory, thereby making it possible to distribute the same information as the information held for distribution by said overloaded logical partition.

7. An information distribution system comprising:

a plurality of logical partitions for executing respective Web server programs and distributing home page data requested from users, including one or more logical partition groups having at least two logical partitions that execute respective Web server programs and can distribute the same home page data;

a shared memory that is shared among the logical partitions;

means for monitoring load on each of said logical partitions and detecting overloaded logical partitions;

means for copying home page data of an overloaded logical partition via said shared memory to a minimum-loaded logical partition; and

means for altering the URL of said minimum-loaded logical partition to the same URL as that of said overloaded logical partition.

8. An information distribution system comprising:

a plurality of logical partitions that execute respective Web server programs and distribute home page data requested from users, including one or more logical partition groups having at least two logical partitions capable of executing Web server programs and distributing the same home page data;

a shared memory that is shared among the logical partitions;

a load table that is provided in said shared memory and stores load data indicating the load condition and a predetermined maximum load amount of each logical partition;

a means, provided in one of said logical partitions, for comparing the value of said load data and the value of said maximum load amount to monitor the load on each logical partition, and when the value of said load data exceeds said maximum load amount, causing the logical partition to copy home page data being distributed by the overloaded logical partition to said shared memory; and

means for selecting a logical partition with spare capacity for accommodating the load among said plurality of logical partitions and causing the selected logical partition to acquire the home page data that has been copied to said shared memory.

9. An information distribution system comprising:

a plurality of logical partitions that execute respective Web server programs and distribute home page data requested from users, including one or more logical partition groups having at least two logical partitions capable of executing Web server programs and distributing the same home page data;

a shared memory that is shared among the logical partitions;

means for comparing the value of a predetermined maximum load amount with the value of load data per unit time to monitor the load on each logical partition, and when the value of said load data exceeds said maximum load amount, then causing the logical partition to copy home page data being distributed by the overloaded logical partition to said shared memory; and

means for selecting a logical partition with spare capacity for accommodating the load among said plurality of logical partitions, excepting a logical partition distributing a single type of home page data by itself, and causing the selected logical partition to acquire the home page data that has been copied to said shared memory.

10. An information distribution system comprising:

a plurality of logical partitions that execute respective Web server programs and distribute home page data requested from users, including one or more logical partition groups having at least two logical partitions capable of executing Web server programs and distributing the same home page data;

a shared memory that is shared among the logical partitions;

a load table, provided in said shared memory for each logical partition, that stores the type of home page data distributed by the logical partition, load data indicating a load condition thereon, and a predetermined maximum load amount;

means, provided in one of the logical partitions, for comparing the value of the load data with the maximum load amount to monitor the load on each logical partition, and when the value of said load data exceeds said maximum load amount, then causing the overloaded logical partition to copy the home page data being distributed thereby to said shared memory;

means for setting the load data value in said load table for a logical partition having the same type of home page data as the home page data being distributed by said overloaded logical partition and the load data value in said load table for a logical partition that distributes a single type of home page data by itself to the maximum value; and

means for selecting a minimum-loaded logical partition among said plurality of logical partitions by referring the load tables and causing the selected logical partition to acquire the home page data that has been copied to the shared memory.

11. A load balancing method for an information distribution system having a plurality of information distribution units for distributing information requested by the users, comprising the steps of:

forming one or more information distribution unit groups that allow at least two of said information distribution units to distribute the same information;

monitoring the load on each of said information distribution units; and

transferring information held for distribution by an overloaded information distribution unit to one of the information distribution units in said information distribution unit group, when said overloaded information distribution unit is overloaded because its load exceeds a predetermined load and enabling distribution of the same information as distributed by said overloaded information distribution unit.

12. A load balancing method for an information distribution system having a plurality of logical partitions for distributing information requested by the users, comprising the steps of:

constructing a shared memory that is shared among said plurality of logical partitions;

monitoring a load on each of said logical partitions; and

transferring information that can be distributed by an overloaded logical partition via said shared memory to a more lightly loaded logical partition when said overloaded logical partition is overloaded because its load exceeds a predetermined load.

13. A load balancing method for an information distribution system, comprising the steps of:

forming one or more logical partition groups that allow at least two of said logical partitions to distribute the same home page data;

forming a shared memory that is shared among said plurality of logical partitions;

monitoring a load on each of said logical partitions; and

transferring information held for distribution by an overloaded logical partition via said shared memory to one of the logical partitions with spare capacity for accommodating the load in said logical partition group, thereby enabling the distribution of the same home page data as distributed by said overloaded logical partition when said overloaded logical partition is overloaded because its load exceeds a predetermined load.