Congestion management in a distributed computer system multiplying current variable injection rate with a constant to set new variable injection rate at source node
AssigneesHewlett-Packard Company, IBM Corporation, Compaq Computer Corporation, Adaptec, Inc.
InventorsRenato J. Recio, David J. Garcia, Michael R. Krause, Patricia A. Thaler, John C. Krause
Life of this patent
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Abstract
A distributed computer system includes links and routing devices coupled between the links and routing frames between the links. Each of the routing devices includes a congestion control mechanism for detecting congestion at the routing device and responding to detected congestion by gradually reducing an injection rate of frames routed from the routing device.
Claims23
A distributed computer system comprising:
- links;
- and
- end stations coupled between the links, wherein types of end stations include endnodes which originate or consume frames and routing devices which route frames between the links and do not originate or consume frames, wherein the end stations include a first source endnode which originates frames at a variable injection rate, wherein the first source endnode includes:
- a congestion control mechanism responding to detected congestion by multiplicatively decreasing the variable injection rate,
- wherein the variable injection rate (IR) is multiplicatively decreased according to IR(i+1)=IR(i)*1/F1, wherein F1 is a constant, wherein IR(i) is equal to a previous variable injection rate and IR(i+1) is equal to a new variable injection rate.
A method of controlling congestion in a distributed computer system having links and end stations coupled between the links, wherein types of end stations include endnodes which originate or consume frames and routing devices which route frames between the links and do not originate or consume frames, the method comprising:
- originating, from a first source endnode, frames at a variable injection rate;
- detecting congestion;
- and
- multiplicatively decreasing the variable injection rate in response to the detected congestion including multiplicatively decreasing the variable injection rate (IR) according to IR(i+1)=IR(i)*1/F1, wherein F1 is a constant, wherein IR(i) is equal to a previous variable injection rate and IR(i+1) is equal to a new variable injection rate.
A distributed computer system comprising:
- links;
- and
- end stations coupled between the links, wherein types of end stations include endnodes which originate or consume frames and routing devices which route frames between the links and do not originate or consume frames, wherein the end stations include a first source endnode which originates frames at a variable injection rate, wherein at least one routing device includes a congestion control mechanism responding to detected congestion by dropping frames that are marked droppable for a time period, and wherein the first source endnode includes:
- a congestion control mechanism responding to detected congestion by multiplicatively decreasing the variable injection rate and responding to detected subsiding of congestion by multiplicatively increasing the variable injection rate, wherein the variable injection rate (IR) is multiplicatively decreased according to IR(i+1)=IR(i)*1/F1, wherein F1 is a constant, wherein the variable injection rate (IR) is multiplicatively increased according to IR(i+1)=IR(i)*F2, wherein F2 is a constant, wherein IR(i) is equal to a previous variable injection rate and IR(i+1) is equal to a new variable injection rate.
Dependencies are inferred from the claim text.