Data communication apparatus, data transmission method, and computer system

A data transmission method of transmitting data through a relay device, comprising:

• calculating, by a computer, an effective transfer speed of the data based on a difference between an actual arrival time at which response data to transmitted transmission data has arrived and a predictive arrival time calculated by multiplying the number of relay devices passed until the response data arrives by a transfer delay time necessary to pass through one relay device and a buffer size of the relay device on a communication path of the data;
• calculating, by the computer, a transmission interval of transmission data by subtracting a value obtained by dividing a data length of the data by a non-congestion transfer speed at which congestion does not occur from a value obtained by dividing the data length by the effective transfer speed;
• and
• performing transmission control of transmission data based on the calculated transmission interval.

A data transmission method of transmitting data to another data communication apparatus through a relay device, comprising:

• calculating an effective transfer speed (t=h×B/d) of the data by dividing a product (h×B) of a buffer size (B) of the relay device on a communication path and the number (h) of relay devices passed until the response data transmitted from the other data communication apparatus arrives at the data communication apparatus by a difference (d) between an actual arrival time at which response data to transmission data transmitted to the other data communication apparatus has arrived and a predictive arrival time by a transfer delay time necessary to pass through one relay device and a buffer size of the relay device on a communication path of the data;
• calculating a limitation size based on the calculated effective transfer speed;
• and
• transmitting data such that a total data amount that is a sum of data amounts of transmission data in which response data to transmission data transmitted to the other data communication apparatus does not arrive is a limitation size or less.

A computer system, comprising:

• a communication network configured to include a plurality of relay devices;
• and
• a plurality of computation nodes configured to perform transmission and reception of data through the communication network,
• wherein the computer node comprises
• a transmission interval calculator configured to calculate an effective transfer speed of the data based on a difference between an actual arrival time at which response data to transmission data transmitted to the other computation node has arrived and a predictive arrival time calculated by multiplying the number of relay devices passed until the response data transmitted from the other computation node arrives at the computation node by a transfer delay time necessary to pass through one relay device and a buffer size of the relay device on a communication path of the data, and calculate a transmission interval of transmission data by subtracting a value obtained by dividing a data length of the data by a non-congestion transfer speed at which congestion does not occur from a value obtained by dividing the data length by the effective transfer speed, and
• a transmission controller configured to perform transmission control of transmission data based on the calculated transmission interval.

A computer system, comprising:

• a communication network configured to include a relay device;
• and
• a plurality of computation nodes configured to perform transmission and reception of data through the communication network,
• wherein the computer node comprises
• a transmission controller configured to transmit data such that a total data amount that is a sum of data amounts of transmission data in which response data to transmission data transmitted to the other computation node does not arrive is a limitation size or less;
• and
• a limitation size calculator configured to calculate an effective transfer speed (t=h×B/d) of the data by dividing a product (h×B) of a buffer size (B) of the relay device on a communication path and the number (h) of relay devices passed until the response data transmitted from the other data communication apparatus arrives at the data communication apparatus by a difference (d) between an actual arrival time at which response data to transmission data transmitted to the other computation node has arrived and a predictive arrival time by a transfer delay time necessary to pass through one relay device and a buffer size of the relay device on a communication path of the data, and calculate the limitation size based on the calculated effective transfer speed.