# US 10,122,621 B2 · Modified consensus protocol for eliminating heartbeat network traffic > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,621 B2 - Document ID: US10122621B2 - Status: Granted - Kind: B2 - Application number: 15/184,173 - Filed: 2016-06-16 - Published: 2017-12-21 - Granted: 2018-11-06 - Earliest claimed: 2016-06-16 - Assignees: Sap SE - Applicants: Sap SE - Inventors: Ivan Schreter - Web page: https://patentgrep.com/patent/US10122621B2 ## CPC - H04L 45/28: using route fault recovery - H04L 41/0853: by actively collecting configuration information or by backing up configuration information - H04L 43/0811: by checking connectivity - H04L 43/16: Threshold monitoring - H04L 45/46: {Cluster building} - H04L 67/10: in which an application is distributed across nodes in the network (software deployment G06F8/60; multiprogramming arrangements G06F9/46) - H04W 4/08: User group management - G06F 11/1425: {by reconfiguration of node membership} - G06F 11/184: {where the redundant components implement processing functionality} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A computing system in data communication with a plurality of nodes that make up a distributed computing cluster can detect an absence of communication from a node of the plurality of nodes over a time period that exceeds a predefined threshold time period. The computing system can query an instance of a central topology manager for the plurality of nodes regarding liveness of the node from which the absence of communication was detected and can attempting to re-initiate communication with the node when the instance of the central topology manager indicates that the node is live. ## Claims ### Claim 1 A computer-implemented method, comprising: detecting, by a computing system in data communication with a plurality of nodes comprising a distributed computing cluster implementing a consensus protocol, an absence of communication from a master node of the plurality of nodes over a time period that exceeds a predefined threshold time period, the absence of communication comprising the master node failing to respond to the computing system within a threshold quantity of time; querying, by the computing system, a central topology manager tracking a liveness of each of the plurality of nodes comprising the distributed computing cluster, the central topology manager being queried to determine a liveness of the master node from which the absence of communication was detected; and in response to the central topology manager indicating that the master node is live, attempting, by the computing system, to re-initiate communication with the master node. ### Claim 2 (depends on 1) A computer-implemented method as in claim 1, wherein the computing system comprises another node of the plurality of nodes. ### Claim 3 (depends on 1) A computer-implemented method as in claim 1, wherein the computing system comprises a client machine in communication with the distributed computing cluster. ### Claim 4 (depends on 1) A computer-implemented method as in claim 1, wherein the re-initiating comprises retrying a failed communication with the master node. ### Claim 5 (depends on 1) A computer-implemented method as in claim 1, wherein the re-initiating comprises ceasing the communication from the master node of the distributed computing cluster to a follower node of the distributed computing cluster. ### Claim 6 (depends on 1) A computer-implemented method as in claim 1, wherein the re-initiating comprises starting a new master election process on a follower node of the plurality of nodes. ### Claim 7 A computer program product comprising a non-transitory machine-readable medium storing instructions that, when executed by at least one programmable processor, cause operations comprising: detecting, by a computing system in data communication with a plurality of nodes comprising a distributed computing cluster implementing a consensus protocol, an absence of communication from a master node of the plurality of nodes over a time period that exceeds a predefined threshold time period, the absence of communication comprising the master node failing to respond to the computing system within a threshold quantity of time; querying, by the computing system, a central topology manager tracking a liveness of each of the plurality of nodes comprising the distributed computing cluster, the central topology manager being queried to determine a liveness of the master node from which the absence of communication was detected; and in response to the central topology manager indicating that the master node is live, attempting, by the computing system, to re-initiate communication with the master node. ### Claim 8 (depends on 7) A computer program product as in claim 7, wherein the computing system comprises another node of the plurality of nodes. ### Claim 9 (depends on 7) A computer program product as in claim 7, wherein the computing system comprises a client machine in communication with the distributed computing cluster. ### Claim 10 (depends on 7) A computer program product as in claim 7, wherein the re-initiating comprises retrying a failed communication with the master node. ### Claim 11 (depends on 7) A computer program product as in claim 7, wherein the re-initiating comprises ceasing the communication from the master node of the distributed computing cluster to a follower node of the distributed computing cluster. ### Claim 12 (depends on 7) A computer program product as in claim 7, wherein the re-initiating comprises starting a new master election process on a follower node of the plurality of nodes. ### Claim 13 A system, comprising: at least one data processor; and at least one memory storing instructions, which when executed by the at least one data processor, cause operations comprising: detecting, by a computing system in data communication with a plurality of nodes comprising a distributed computing cluster implementing a consensus protocol, an absence of communication from a master node of the plurality of nodes over a time period that exceeds a predefined threshold time period, the absence of communication comprising the master node failing to respond to the computing system within a threshold quantity of time; querying, by the computing system, a central topology manager tracking a liveness of each of the plurality of nodes comprising the distributed computing cluster, the central topology manager being queried to determine a liveness of the master node from which the absence of communication was detected; and in response to the central topology manager indicating that the master node is live, attempting, by the computing system, to re-initiate communication with the master node. ### Claim 14 (depends on 13) A system as in claim 13, wherein the computing system comprises another node of the plurality of nodes. ### Claim 15 (depends on 13) A system as in claim 13, wherein the computing system comprises a client machine in communication with the distributed computing cluster. ### Claim 16 (depends on 13) A system as in claim 13, wherein the re-initiating comprises retrying a failed communication with the master node. ### Claim 17 (depends on 13) A system as in claim 13, wherein the re-initiating comprises ceasing the communication from the master node of the distributed computing cluster to a follower node of the distributed computing cluster. ### Claim 18 (depends on 13) A system as in claim 13, wherein the re-initiating comprises starting a new master election process on a follower node of the plurality of nodes.