Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: Techniques for background task scheduling based on shared background bandwidth are described. A method for background task scheduling based on shared background bandwidth may include receiving a request to perform one or more background tasks on a storage server of a storage service in a provider network, determining a priority of each of the one or more background tasks, wherein each background task is associated with a size parameter and a temporal parameter, and wherein the priority of each of the one or more background tasks is based at least on its associated size parameter and temporal parameter, determining a task type associated with each background task, adding each background task to one of a plurality of task queues associated with different task types, wherein each task queue is associated with a bandwidth allocation, and scheduling the one or more background tasks to be performed based on their priority and the bandwidth allocation.

Abstract: A data storage system includes multiple head nodes and data storage sleds. A control plane of the data storage system designates, for a volume partition, one of the head nodes to function as a primary head node storing a primary replica of the volume partition and designates two or more other head nodes to function as reserve head nodes storing reserve replicas of the volume partition. Additionally, the primary head node causes volume data for the volume partition to be erasure encoded and stored on multiple mass storage devices in different ones of the data storage sleds.

Abstract: Techniques are described for using in-band communication channels to exchange state information between components of a distributed storage environment, including between client computing devices and storage servers hosting network-connected block storage volumes. The exchange of the state information can be used, for example, to inform client computing devices of relevant events involving one or more storage volumes attached to compute instances (for example, virtual machines (VMs)) running on the client computing devices, involving one or more failover servers storing backup copies of one or more storage volumes, or involving any other relevant system components.

Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: Systems and methods are disclosed for reducing interdependency among control plane on a block storage system. Embodiments described herein can implement a key-value data store on the data plane servers. In one embodiment, the key-value store stores data regarding placement constraints and enables the block storage system to make placement decisions without control plane dependencies. In another embodiment, the key-value store persisted by the data plane enable the block storage system to migrate volumes while maintaining performance settings.

Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: A system that hosts computing resources may implement optimistically granting permission to host computing resources. A request for permission to host a computing resource may be received by a control plane. If the control plane determines that the resource host is the first to request permission to host the resource, then the control plane may store an indication of permission that blocks other resource hosts from obtaining permission to host the computing resource and sending an acknowledgement of permission to the resource host that requested permission.

Abstract: Generally described, one or more aspects of the present application correspond to techniques for automatic recovery from dual isolation in which both the primary and secondary replicas of a volume are stored on isolating servers. The disclosed techniques use handshakes between the client and the replicas to determine which has a better health score. The replica with the better health score becomes the primary replica, and confirms that it and the secondary replica are both in an isolating state. In response, the primary replica seeks a solo blessing, undoes the isolating state at the volume level (the server host will still be in isolating state), and continues handling I/O and peer replication until its healthy peer is complete. These techniques can avoid availability drops when the servers hosting the primary and secondary replicas of a volume enter the isolating state at around the same time.

Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: A data storage system includes multiple head nodes and data storage sleds. A control plane of the data storage system designates, for a volume partition, one of the head nodes to function as a primary head node storing a primary replica of the volume partition and designates two or more other head nodes to function as reserve head nodes storing reserve replicas of the volume partition. Additionally, the primary head node causes volume data for the volume partition to be erasure encoded and stored on multiple mass storage devices in different ones of the data storage sleds.