Patents by Inventor David Alan Lutz
David Alan Lutz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11899684Abstract: A system that implements a data storage service may store data on behalf of clients in multiple replicas on respective computing nodes. The system may employ an external service to select a master replica for a replica group. The master replica may service consistent read operations and/or write operations that are directed to the replica group (or to a data partition stored by the replica group). The master replica may employ a quorum based mechanism for performing replicated write operations, and a local lease mechanism for determining the replica authorized to perform consistent reads, even when the external service is unavailable. The master replica may propagate local leases to replica group members as replicated writes. If another replica assumes mastership for the replica group, it may not begin servicing consistent read operations that are directed to the replica group until the lease period for a current local lease expires.Type: GrantFiled: September 10, 2021Date of Patent: February 13, 2024Assignee: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, David Alan Lutz
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Patent number: 11894972Abstract: A system that implements a data storage service may store data on behalf of storage service clients. The system may maintain data in multiple replicas of various partitions that are stored on respective computing nodes in the system. The system may employ a single master failover protocol, usable when a replica attempts to become the master replica for a replica group of which it is a member. Attempting to become the master replica may include acquiring a lock associated with the replica group, and gathering state information from the other replicas in the group. The state information may indicate whether another replica supports the attempt (in which case it is included in a failover quorum) or stores more recent data or metadata than the replica attempting to become the master (in which case synchronization may be required). If the failover quorum includes enough replicas, the replica may become the master.Type: GrantFiled: July 8, 2022Date of Patent: February 6, 2024Assignee: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, Jakub Kulesza, David Alan Lutz
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Publication number: 20230400990Abstract: A system that implements a scalable data storage service may maintain tables in a data store on behalf of storage service clients. The service may maintain table data in multiple replicas of partitions that are stored on respective computing nodes in the system. In response to detecting an anomaly in the system, detecting a change in data volume on a partition or service request traffic directed to a partition, or receiving a service request from a client to split a partition, the data storage service may create additional copies of a partition replica using a physical copy mechanism. The data storage service may issue a split command defined in an API for the data store to divide the original and additional replicas into multiple replica groups, and to configure each replica group to maintain a respective portion of the table data that was stored in the partition before the split.Type: ApplicationFiled: June 7, 2023Publication date: December 14, 2023Applicant: Amazon Technologies, Inc.Inventors: Stefano Stefani, Timothy Andrew Rath, Chiranjeeb Buragahain, Yan Valerie Leshinsky, David Alan Lutz, Jakub Kulesza, Wei Xiao, Jai Vasanth
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Publication number: 20230283681Abstract: A system that provides services to clients may receive and service requests, various ones of which may require different amounts of work. The system may determine whether it is operating in an overloaded or underloaded state based on a current work throughput rate, a target work throughput rate, a maximum request rate, or an actual request rate, and may dynamically adjust the maximum request rate in response. For example, if the maximum request rate is being exceeded, the maximum request rate may be raised or lowered, dependent on the current work throughput rate. If the target or committed work throughput rate is being exceeded, but the maximum request rate is not being exceeded, a lower maximum request rate may be proposed. Adjustments to the maximum request rate may be made using multiple incremental adjustments. Service request tokens may be added to a leaky token bucket at the maximum request rate.Type: ApplicationFiled: March 3, 2023Publication date: September 7, 2023Applicant: Amazon Technologies, Inc.Inventors: Wei Xiao, David Alan Lutz, Timothy Andrew Rath, Maximiliano Maccanti, Miguel Mascarenhas Filipe, David Craig Yanacek
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Publication number: 20230273937Abstract: Methods and apparatus for conditional master election in a distributed database are described. A plurality of replicas of a database object are stored by a distributed database service. Some types of operations corresponding to client requests directed at the database object are to be coordinated by a master replica. Client access to the database object is enabled prior to election of a master replica. In response to a triggering condition, a particular replica is elected master. The master coordinates implementation of operations with one or more other replicas in response to client requests.Type: ApplicationFiled: May 9, 2023Publication date: August 31, 2023Applicant: Amazon Technologies, Inc.Inventors: Akshat Vig, Timothy Andrew Rath, Stuart Henry Seelye Marshall, Rande A. Blackman, David Alan Lutz, Jian Wang, Jiandan Zheng, Janani Narayanan
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Patent number: 11709600Abstract: A system that implements a scalable data storage service may maintain tables in a data store on behalf of storage service clients. The service may maintain table data in multiple replicas of partitions that are stored on respective computing nodes in the system. In response to detecting an anomaly in the system, detecting a change in data volume on a partition or service request traffic directed to a partition, or receiving a service request from a client to split a partition, the data storage service may create additional copies of a partition replica using a physical copy mechanism. The data storage service may issue a split command defined in an API for the data store to divide the original and additional replicas into multiple replica groups, and to configure each replica group to maintain a respective portion of the table data that was stored in the partition before the split.Type: GrantFiled: July 10, 2020Date of Patent: July 25, 2023Assignee: Amazon Technologies, Inc.Inventors: Stefano Stefani, Timothy Andrew Rath, Chiranjeeb Buragahain, Yan Valerie Leshinsky, David Alan Lutz, Jakub Kulesza, Wei Xiao, Jai Vasanth
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Patent number: 11687555Abstract: Methods and apparatus for conditional master election in a distributed database are described. A plurality of replicas of a database object are stored by a distributed database service. Some types of operations corresponding to client requests directed at the database object are to be coordinated by a master replica. Client access to the database object is enabled prior to election of a master replica. In response to a triggering condition, a particular replica is elected master. The master coordinates implementation of operations with one or more other replicas in response to client requests.Type: GrantFiled: November 15, 2019Date of Patent: June 27, 2023Assignee: Amazon Technologies, Inc.Inventors: Akshat Vig, Timothy Andrew Rath, Stuart Henry Seelye Marshall, Rande A. Blackman, David Alan Lutz, Jian Wang, Jiandan Zheng, Janani Narayanan
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Patent number: 11601512Abstract: A system that provides services to clients may receive and service requests, various ones of which may require different amounts of work. The system may determine whether it is operating in an overloaded or underloaded state based on a current work throughput rate, a target work throughput rate, a maximum request rate, or an actual request rate, and may dynamically adjust the maximum request rate in response. For example, if the maximum request rate is being exceeded, the maximum request rate may be raised or lowered, dependent on the current work throughput rate. If the target or committed work throughput rate is being exceeded, but the maximum request rate is not being exceeded, a lower maximum request rate may be proposed. Adjustments to the maximum request rate may be made using multiple incremental adjustments. Service request tokens may be added to a leaky token bucket at the maximum request rate.Type: GrantFiled: April 30, 2021Date of Patent: March 7, 2023Assignee: Amazon Technologies, IncInventors: Wei Xiao, David Alan Lutz, Timothy Andrew Rath, Maximiliano Maccanti, Miguel Mascarenhas Filipe, David Craig Yanacek
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Patent number: 11507480Abstract: Disclosed are various embodiments for distributing data items within a plurality of nodes. A data item that is subject to a data item update request is updated from a master node to a plurality of slave notes. The update of the data item is determined to be locality-based durable based at least in part on acknowledgements received from the slave nodes. Upon detection that the master node has failed, a new master candidate is determined via an election among the plurality of slave nodes.Type: GrantFiled: November 9, 2018Date of Patent: November 22, 2022Assignee: Amazon Technologies, Inc.Inventors: Michael T. Helmick, Jakub Kulesza, Timothy Andrew Rath, Stefano Stefani, David Alan Lutz
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Publication number: 20220345358Abstract: A system that implements a data storage service may store data on behalf of storage service clients. The system may maintain data in multiple replicas of various partitions that are stored on respective computing nodes in the system. The system may employ a single master failover protocol, usable when a replica attempts to become the master replica for a replica group of which it is a member. Attempting to become the master replica may include acquiring a lock associated with the replica group, and gathering state information from the other replicas in the group. The state information may indicate whether another replica supports the attempt (in which case it is included in a failover quorum) or stores more recent data or metadata than the replica attempting to become the master (in which case synchronization may be required). If the failover quorum includes enough replicas, the replica may become the master.Type: ApplicationFiled: July 8, 2022Publication date: October 27, 2022Applicant: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, Jakub Kulesza, David Alan Lutz
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Patent number: 11388043Abstract: A system that implements a data storage service may store data on behalf of storage service clients. The system may maintain data in multiple replicas of various partitions that are stored on respective computing nodes in the system. The system may employ a single master failover protocol, usable when a replica attempts to become the master replica for a replica group of which it is a member. Attempting to become the master replica may include acquiring a lock associated with the replica group, and gathering state information from the other replicas in the group. The state information may indicate whether another replica supports the attempt (in which case it is included in a failover quorum) or stores more recent data or metadata than the replica attempting to become the master (in which case synchronization may be required). If the failover quorum includes enough replicas, the replica may become the master.Type: GrantFiled: March 27, 2020Date of Patent: July 12, 2022Assignee: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, Jakub Kulesza, David Alan Lutz
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Publication number: 20210406279Abstract: A system that implements a data storage service may store data on behalf of clients in multiple replicas on respective computing nodes. The system may employ an external service to select a master replica for a replica group. The master replica may service consistent read operations and/or write operations that are directed to the replica group (or to a data partition stored by the replica group). The master replica may employ a quorum based mechanism for performing replicated write operations, and a local lease mechanism for determining the replica authorized to perform consistent reads, even when the external service is unavailable. The master replica may propagate local leases to replica group members as replicated writes. If another replica assumes mastership for the replica group, it may not begin servicing consistent read operations that are directed to the replica group until the lease period for a current local lease expires.Type: ApplicationFiled: September 10, 2021Publication date: December 30, 2021Applicant: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, David Alan Lutz
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Publication number: 20210329077Abstract: A system that provides services to clients may receive and service requests, various ones of which may require different amounts of work. The system may determine whether it is operating in an overloaded or underloaded state based on a current work throughput rate, a target work throughput rate, a maximum request rate, or an actual request rate, and may dynamically adjust the maximum request rate in response. For example, if the maximum request rate is being exceeded, the maximum request rate may be raised or lowered, dependent on the current work throughput rate. If the target or committed work throughput rate is being exceeded, but the maximum request rate is not being exceeded, a lower maximum request rate may be proposed. Adjustments to the maximum request rate may be made using multiple incremental adjustments. Service request tokens may be added to a leaky token bucket at the maximum request rate.Type: ApplicationFiled: April 30, 2021Publication date: October 21, 2021Applicant: Amazon Technologies, Inc.Inventors: Wei Xiao, David Alan Lutz, Timothy Andrew Rath, Maximiliano Maccanti, Miguel Mascarenhas Filipe, David Craig Yanacek
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Patent number: 11120044Abstract: A system that implements a data storage service may store data on behalf of clients in multiple replicas on respective computing nodes. The system may employ an external service to select a master replica for a replica group. The master replica may service consistent read operations and/or write operations that are directed to the replica group (or to a data partition stored by the replica group). The master replica may employ a quorum based mechanism for performing replicated write operations, and a local lease mechanism for determining the replica authorized to perform consistent reads, even when the external service is unavailable. The master replica may propagate local leases to replica group members as replicated writes. If another replica assumes mastership for the replica group, it may not begin servicing consistent read operations that are directed to the replica group until the lease period for a current local lease expires.Type: GrantFiled: November 27, 2019Date of Patent: September 14, 2021Assignee: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, David Alan Lutz
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Patent number: 10999381Abstract: A system that provides services to clients may receive and service requests, various ones of which may require different amounts of work. The system may determine whether it is operating in an overloaded or underloaded state based on a current work throughput rate, a target work throughput rate, a maximum request rate, or an actual request rate, and may dynamically adjust the maximum request rate in response. For example, if the maximum request rate is being exceeded, the maximum request rate may be raised or lowered, dependent on the current work throughput rate. If the target or committed work throughput rate is being exceeded, but the maximum request rate is not being exceeded, a lower maximum request rate may be proposed. Adjustments to the maximum request rate may be made using multiple incremental adjustments. Service request tokens may be added to a leaky token bucket at the maximum request rate.Type: GrantFiled: April 5, 2019Date of Patent: May 4, 2021Assignee: Amazon Technologies, Inc.Inventors: Wei Xiao, David Alan Lutz, Timothy Andrew Rath, Maximiliano Maccanti, Miguel Mascarenhas Filipe, David Craig Yanacek
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Patent number: 10929240Abstract: A system that implements a data storage service may store data on behalf of storage service clients. The system may maintain data in multiple replicas of partitions that are stored on respective computing nodes in the system. A master replica for a replica group may increment a membership version indicator for the group, and may propagate metadata (including the membership version indicator) indicating a membership change for the group to other members of the group. Propagating the metadata may include sending a log record containing the metadata to the other replicas to be appended to their respective logs. Once the membership change becomes durable, it may be committed. A replica attempting to become the master of a replica group may determine that another replica in the group has observed a more recent membership version, in which case logs may be synchronized or snipped, or the attempt may be abandoned.Type: GrantFiled: February 2, 2018Date of Patent: February 23, 2021Assignee: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, Jakub Kulesza, David Alan Lutz
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Publication number: 20200341657Abstract: A system that implements a scalable data storage service may maintain tables in a data store on behalf of storage service clients. The service may maintain table data in multiple replicas of partitions that are stored on respective computing nodes in the system. In response to detecting an anomaly in the system, detecting a change in data volume on a partition or service request traffic directed to a partition, or receiving a service request from a client to split a partition, the data storage service may create additional copies of a partition replica using a physical copy mechanism. The data storage service may issue a split command defined in an API for the data store to divide the original and additional replicas into multiple replica groups, and to configure each replica group to maintain a respective portion of the table data that was stored in the partition before the split.Type: ApplicationFiled: July 10, 2020Publication date: October 29, 2020Applicant: Amazon Technologies, Inc.Inventors: Stefano Stefani, Timothy Andrew Rath, Chiranjeeb Buragahain, Yan Valerie Leshinsky, David Alan Lutz, Jakub Kulesza, Wei Xiao, Jai Vasanth
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Patent number: 10754854Abstract: A distributed database management system may comprise a plurality of computing nodes. A request to update an item maintained by the system may be acknowledged as durable and committed once an entry corresponding to the request has been written to a log file and quorum among the computing nodes has been achieved. Improved consistency may be achieved by maintaining snapshots of committed item states within queryable in-memory snapshot data structures. Range queries may be performed by merging a secondary index with the snapshots and applying filters. Projections may be completed by retrieving additional data from an item collection maintain on one or more storage devices.Type: GrantFiled: March 19, 2018Date of Patent: August 25, 2020Assignee: Amazon Technologies, Inc.Inventors: Xianglong Huang, David Alan Lutz, Wei Xiao, Maximiliano Maccanti, Somasundaram Perianayagam, Rande A. Blackman, Stuart Henry Seelye Marshall
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Publication number: 20200228393Abstract: A system that implements a data storage service may store data on behalf of storage service clients. The system may maintain data in multiple replicas of various partitions that are stored on respective computing nodes in the system. The system may employ a single master failover protocol, usable when a replica attempts to become the master replica for a replica group of which it is a member. Attempting to become the master replica may include acquiring a lock associated with the replica group, and gathering state information from the other replicas in the group. The state information may indicate whether another replica supports the attempt (in which case it is included in a failover quorum) or stores more recent data or metadata than the replica attempting to become the master (in which case synchronization may be required). If the failover quorum includes enough replicas, the replica may become the master.Type: ApplicationFiled: March 27, 2020Publication date: July 16, 2020Applicant: Amazon Technologies, Inc.Inventors: Timothy Andrew Rath, Jakub Kulesza, David Alan Lutz
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Patent number: 10712950Abstract: A system that implements a scalable data storage service may maintain tables in a data store on behalf of storage service clients. The service may maintain table data in multiple replicas of partitions that are stored on respective computing nodes in the system. In response to detecting an anomaly in the system, detecting a change in data volume on a partition or service request traffic directed to a partition, or receiving a service request from a client to split a partition, the data storage service may create additional copies of a partition replica using a physical copy mechanism. The data storage service may issue a split command defined in an API for the data store to divide the original and additional replicas into multiple replica groups, and to configure each replica group to maintain a respective portion of the table data that was stored in the partition before the split.Type: GrantFiled: June 8, 2015Date of Patent: July 14, 2020Assignee: Amazon Technologies, Inc.Inventors: Stefano Stefani, Timothy Andrew Rath, Chiranjeeb Buragahain, Yan Valerie Leshinsky, David Alan Lutz, Jakub Kulesza, Wei Xiao, Jai Vasanth