Load balancer, load balancing method, and load balancing system

Abstract

This allows for controlling the number of servers used to distribute processing, preventing connection drops on servers that distribute processing. [Solution] The load balancer (2) includes a storage unit (210) that stores the optimal number of connections (CS) for each server when distributing processing to each of a plurality of servers (3), and a control unit (200) that determines which servers to distribute processing to from among the plurality of servers and controls the connections between the external device (4) and the servers. The optimal number of connections is smaller than the upper limit (CL) of the number of connections that a server can handle. The control unit acquires the total number of connections (CCT) between the external device and the servers at a predetermined acquisition timing, and determines the number of servers to distribute processing to based on the acquired total number of connections and the optimal number of connections.

Claims

1. A memory unit that stores the optimal number of connections for each server when distributing processing across multiple servers, The system includes a control unit that determines which of the multiple servers will distribute the processing and controls the connection between the external device and the server, The optimal number of connections is smaller than the upper limit of the number of connections that the server can process. The control unit acquires the total number of connections between the external device and the server at a predetermined acquisition timing, and determines the number of servers to distribute the processing based on the acquired total number of connections and the optimal value for the number of connections. A load balancer characterized by the following features.

2. The load balancer according to claim 1, characterized in that the control unit periodically obtains the total number of connections and determines the number of servers to distribute the processing when the absolute value of the difference between the obtained total number of connections and the optimal number of connections exceeds a threshold.

3. The memory unit further stores the number of servers that distribute the processing, which is set for multiple different time periods based on the time change in the number of connections in the past. The control unit changes the number of servers to which the processing is distributed when the start time of each time period arrives to the number of servers stored in the storage unit, and then periodically reviews the number of servers to which the processing is distributed based on the total number of connections and the optimal value of the number of connections. The load balancer according to claim 1 or 2, characterized in that it is as described above.

4. The control unit determines the number of servers to distribute the processing to as an integer value obtained by dividing the total number of connections by the optimal number of connections and rounding up the decimal part of that value. The load balancer according to feature 1.

5. The load balancer When distributing processing across multiple servers, the system stores an optimal number of connections for each server that is smaller than the upper limit of the number of connections that the server can handle. The total number of connections between the external device and the server is obtained at a predetermined acquisition timing, and the number of servers to distribute the processing is determined based on the obtained total number of connections and the optimal value of the number of connections. Based on the determined number of servers, the system determines which servers will distribute the processing among the multiple servers and controls the connection with the external device. A load balancing method characterized by the following:

6. It includes multiple servers with the same functionality and a load balancer. The aforementioned load balancer is A storage unit that stores the optimal number of connections for each server when distributing processing to each of the aforementioned multiple servers, The system includes a control unit that determines which of the multiple servers will distribute the processing and controls the connection between the external device and the server, The optimal number of connections is smaller than the upper limit of the number of connections that the server can process. The control unit acquires the total number of connections between the external device and the server at a predetermined acquisition timing, and determines the number of servers to distribute the processing based on the acquired total number of connections and the optimal value for the number of connections. A load balancing system characterized by the following:

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