Abstract: A data storage system includes multiple head nodes and multiple data storage sleds mounted in a rack. For a particular volume or volume partition one of the head nodes is designated as a primary head node for the volume or volume partition. The primary head node is configured to store data for the volume in a data storage of the primary head node and cause the data to be replicated to a secondary head node. The primary head node is also configured to cause the data for the volume to be stored in a plurality of respective mass storage devices each in different ones of the plurality of data storage sleds of the data storage system.

Abstract: A data storage system includes multiple head nodes and data storage sleds. The data storage sleds include multiple mass storage devices and a sled controller. Respective ones of the head nodes are configured to obtain credentials for accessing particular portions of the mass storage devices of the data storage sleds. A sled controller of a data storage sled determines whether a head node attempting to perform a write on a mass storage device of a data storage sled that includes the sled controller is presenting with the write request a valid credential for accessing the mass storage devices of the data storage sled. If the credentials are valid, the sled controller causes the write to be performed and if the credentials are invalid, the sled controller returns a message to the head node indicating that it has been fenced off from the mass storage device.

Abstract: A data storage system includes a rack, multiple head nodes, multiple data storage sleds, and at least two networking devices. The at least two network devices are configured to implement at least two redundant networks within the data storage system. Also, each of the head nodes is assigned at least two network addresses for communication with the data storage sleds of the data storage system via the at least two networking devices. The data storage sleds each include multiple mass storage devices and a sled controller that is configured to couple with the at least two network switches. IO In some embodiments, the data storage system further includes redundant power systems within a rack in which the head nodes, the data storage sleds, and the at least two networking devices are mounted.

Abstract: A user can set or modify operational parameters of a data volume stored on a network-accessible storage device in a data center. For example, the user may be provided access to a data volume and may request a modification to the operational parameters of the data volume. Instead of modifying the existing data volume, the data center can provision a new data volume and migrate data stored on the existing data volume to the new data volume. While the data migration takes place, the existing data volume may block input/output (I/O) requests and the new data volume may handle such requests instead. Once the data migration is complete, the data center may deallocate the data blocks of the existing data volume such that the data blocks can be reused by other data volumes.

Abstract: Indications of packet processing operations to be performed for packets of a resource group, as well as configuration settings of the group, are obtained. A packet that satisfies a requirement of the configuration settings and meets a fast path criterion is processed at a fast path node configured for the group. In response to determining that another packet does not satisfy a criterion for fast path processing, the other packet is transmitted to an exception path target.

Abstract: A data storage system includes multiple data storage units and a zonal control plane. The zonal control plane assigns volumes to respective ones of the data storage units. The data storage units include multiple head nodes and data storage sleds. At least one of the head nodes implements a local control plane for the data storage unit. Also, the head nodes of each data storage unit are configured to service read and write requests directed to one or more volumes serviced by the data storage unit independent of the zonal control plane.

Abstract: A data storage system includes a head node and mass storage devices. The head node is configured to flush data stored in a storage of the head node to a set of the mass storage devices of the data storage system. A head node may flush both current version data and point-in-time version data to the set of mass storage devices. Also, the data storage system maintains an index that indicates storage locations of data for particular portions of a volume before and after the data is flushed to the set of mass storage devices. In some embodiments an index includes a current version reference for a volume or portion of a volume and one or more point-in-time snapshot references.

Abstract: A data storage system includes a head node and mass storage devices. The head node is configured to flush data stored in a storage of the head node to a set of the mass storage devices of the data storage system. A head node may flush both current version data and point-in-time version data to the set of mass storage devices. Also, the data storage system maintains an index that indicates storage locations of data for particular portions of a volume before and after the data is flushed to the set of mass storage devices. In some embodiments an index includes a current version reference for a volume or portion of a volume and one or more point-in-time snapshot references.

Abstract: Indications of packet processing operations to be performed for packets of a resource group, as well as configuration settings of the group, are obtained. A packet that satisfies a requirement of the configuration settings and meets a fast path criterion is processed at a fast path node configured for the group. In response to determining that another packet does not satisfy a criterion for fast path processing, the other packet is transmitted to an exception path target.

Abstract: A data storage system includes a rack, multiple head nodes, multiple data storage sleds, and at least two networking devices. The at least two network devices are configured to implement at least two redundant networks within the data storage system. Also, each of the head nodes is assigned at least two network addresses for communication with the data storage sleds of the data storage system via the at least two networking devices. The data storage sleds each include multiple mass storage devices and a sled controller that is configured to couple with the at least two network switches. IO In some embodiments, the data storage system further includes redundant power systems within a rack in which the head nodes, the data storage sleds, and the at least two networking devices are mounted.

Abstract: A slave storage is provisioned using metadata of a master B-tree and updates to references (e.g., offsets) pertaining to data operations of the master B-tree. Master-slave pairs can be used to provide data redundancy, and a master copy can include the master B-tree with references to corresponding data. When provisioning a slave copy, the master sends a B-tree copy to the slave, which stores the slave B-tree copy, allocates the necessary space on local storage, and updates respective offsets of the slave B-tree copy to point to the local storage. Data from the master can then be transferred to the slave and stored according to a note and commit process that ensures operational sequence of the data. Operations received to the master during the process can be committed to the slave copy until the slave is consistent with the master and able to take over as master in the event of a failure.

Abstract: A representation of packet processing operations is obtained from a client of a provider network. A set of packet processing nodes is configured at a premise external to the provider network, and the representation is transmitted to the premise. In response to a reception of a network packet, the set of packet processing nodes perform the packet processing operations at the external premise.

Abstract: A distributed system may implement preventing concentrated selection of resource hosts for placing resources within the distributed system. When a request to place a resource at a resource host is received, an evaluation of load metrics for the resource host is made with respect to rejection criteria. If the rejection criteria is satisfied, then the resource host may reject the request to place the resource. If the rejection criteria is not satisfied, then the resource host may not reject the placement of the resource. Rejection criteria may be provided to resource hosts along with the placement request, in some embodiments. Rejection criteria may be changed, weakened, or removed entirely if initial attempts to place a resource are unsuccessful.

Abstract: Systems and methods for provisioning a slave copy for redundant data storage and for writing data to persistent storage in a block-based storage system using sequential operation numbers are provided. In one embodiment, the method includes maintaining a master copy and a slave copy of a data volume, the master copy including data generated by a plurality of operations having respective sequential operation numbers, receiving a write instruction for second data to be added to the master copy, and recording the second data as a note that is not readable. The method may further include sending a copy of the note from the master copy to the slave copy, committing the note to the master copy with a sequential operation number, and committing the copy of the note to the slave copy based in part on the sequential operation number. A B-tree may be created based at least in part on an offset for a write instruction associated with the second data, a length, and an operation number included in the note.

Abstract: A data storage system includes a rack, multiple head nodes, multiple data storage sleds, and at least two networking devices. The at least two network devices are configured to implement at least two redundant networks within the data storage system. Also, each of the head nodes is assigned at least two network addresses for communication with the data storage sleds of the data storage system via the at least two networking devices. The data storage sleds each include multiple mass storage devices and a sled controller that is configured to couple with the at least two network switches. In some embodiments, the data storage system further includes redundant power systems within a rack in which the head nodes, the data storage sleds, and the at least two networking devices are mounted.

Abstract: A data storage system includes multiple head nodes and multiple data storage sleds mounted in a rack. For a particular volume or volume partition one of the head nodes is designated as a primary head node for the volume or volume partition. The primary head node is configured to store data for the volume in a data storage of the primary head node and cause the data to be replicated to a secondary head node. The primary head node is also configured to cause the data for the volume to be stored in a plurality of respective mass storage devices each in different ones of the plurality of data storage sleds of the data storage system.

Abstract: A data storage system includes multiple data storage units and a zonal control plane. The zonal control plane assigns volumes to respective ones of the data storage units. The data storage units include multiple head nodes and data storage sleds. At least one of the head nodes implements a local control plane for the data storage unit. Also, the head nodes of each data storage unit are configured to service read and write requests directed to one or more volumes serviced by the data storage unit independent of the zonal control plane.

Abstract: A data storage system includes multiple head nodes and data storage sleds. The data storage sleds include multiple mass storage devices and a sled controller. Respective ones of the head nodes are configured to obtain credentials for accessing particular portions of the mass storage devices of the data storage sleds. A sled controller of a data storage sled determines whether a head node attempting to perform a write on a mass storage device of a data storage sled that includes the sled controller is presenting with the write request a valid credential for accessing the mass storage devices of the data storage sled. If the credentials are valid, the sled controller causes the write to be performed and if the credentials are invalid, the sled controller returns a message to the head node indicating that it has been fenced off from the mass storage device.

Abstract: A user can set or modify operational parameters of a data volume stored on a network-accessible storage device in a data center. For example, the user may be provided access to a data volume and may request a modification to the operational parameters of the data volume. Instead of modifying the existing data volume, the data center can provision a new data volume and migrate data stored on the existing data volume to the new data volume. While the data migration takes place, the existing data volume may block input/output (I/O) requests and the new data volume may handle such requests instead. Once the data migration is complete, the data center may deallocate the data blocks of the existing data volume such that the data blocks can be reused by other data volumes.

Abstract: A data storage system includes a head node and mass storage devices. The head node is configured to flush data stored in a storage of the head node, based at least in part on one or more triggers being met, from the storage of the head node to a set of the mass storage devices of the data storage system. The flushed data is written to a segment of free storage space across the set of the mass storage devices allocated for the given data flush operation. In some embodiments, a head node may flush both current version data and point-in-time version data to the set of mass storage devices. Also, the data storage system maintains an index that indicates storage locations of data for particular portions of a volume before and after the data is flushed to the set of mass storage devices.