Control of overload in communications networks

In a first system for controlling a gap in a plurality of second systems using gap control to reject overload communication traffic for a particular destination, a method of controlling the gap for rejecting communication traffic to the particular destination in said second systems comprising:

• in the first system, initializing an indication of a gap value when traffic to said particular destination exceeds a predetermined value;
• in the first system, measuring a fraction of communication traffic that cannot be completed to the particular destination;
• responsive to said measuring, adjusting the value of the gap upward if the fraction exceeds a first threshold, downward, but not below zero, if the fraction is less than a second threshold and maintaining the value of the gap if the fraction is between the first and second threshold;
• transmitting the value of the adjusted gap to the second systems;
• and
• repeating the measuring, adjusting, and transmitting steps recurrently.

In a database system, means for controlling a gap value for throttling request message traffic, related to communication traffic, from a plurality of sources, comprising:

• means for transmitting said gap value to said plurality of sources;
• and
• processor means, operating under control of a program for:
• initializing an indication of a gap value;
• measuring a fraction of communication traffic that cannot be processed in the database system;
• responsive to said measuring, adjusting the value of the gap upward if the fraction exceeds a first threshold, downward, but not below zero, if the fraction is less than a second threshold and maintaining the value of the gap if the fraction is between the first and second threshold;
• controlling said means for transmitting to transmit the value of the adjusted gap to the plurality of sources;
• and
• repeating the measuring, adjusting, and controlling steps recurrently.

In a database system, means for calculating a gap value for throttling traffic to a particular destination from a plurality of sources, comprising:

• means for transmitting messages to said plurality of sources;
• and
• processor means operative under the control of a program for:
• initializing an indication of a gap value when traffic to said particular destination exceeds a predetermined value;
• measuring a fraction of traffic that cannot be completed to the particular destination;
• responsive to said measuring, adjusting the value of the gap upward if the fraction exceeds a first threshold, downward, but not below zero, if the fraction is less than a second threshold and maintaining the value of the gap if the fraction is between the first and second threshold;
• controlling said means for transmitting to transmit the value of the adjusted gap to the second systems;
• repeating the measuring, adjusting, and controlling steps recurrently.