Abstract: A block-based storage system may implement efficient replication for restoring a data volume from a reduced durability state. A storage node that is not replicating write requests for a data volume may determine that replication for the data volume is to be enabled. A peer storage node may be identified that maintains a stale replica of the data volume. One or more replication operations may be performed to update stale data chunks in the stale replica of the data volume with current data chunks without updating data chunks in the stale replica of the data volume that are current. Stale replicas that are no longer needed may be deleted according timeouts or the amount of stale data in the replica.

Abstract: A block-based storage system may implement reducing durability state for a data volume. A determination may be made that storage node replicating write requests for a data volume is unavailable. In response, subsequent write requests may be processed according to a reduced durability state for the data volume such that replication for the data volume may be disabled for the storage node. Write requests may then be completed at a fewer number of storage nodes prior to acknowledging the write request as complete. Durability state for the data volume may be increase in various embodiments. A storage node may be identified and replication operations may be performed to synchronize the current data volume at the storage node with a replica of the data volume maintained at the identified storage node.

Abstract: A storage system may implement dynamic configuration of data volumes. Client utilization of a data volume in a storage system may be tracked or monitored. Based on the utilization of the data volume, configuration recommendations to reconfigure the data volume according to data volume offerings may be determined. The data volume may be configured according to an authorized configuration recommendation. In some embodiments, these recommendations may be provided to a client and selection of the configuration recommendation to perform may be received. In some embodiments, a configuration recommendation may be automatically performed based on previously provided authorization to configure the data volume.

Abstract: A block-based storage system may implement reducing durability state for a data volume. A determination may be made that storage node replicating write requests for a data volume is unavailable. In response, subsequent write requests may be processed according to a reduced durability state for the data volume such that replication for the data volume may be disabled for the storage node. Write requests may then be completed at a fewer number of storage nodes prior to acknowledging the write request as complete. Durability state for the data volume may be increase in various embodiments. A storage node may be identified and replication operations may be performed to synchronize the current data volume at the storage node with a replica of the data volume maintained at the identified storage node.

Abstract: Write optimization for block-based storage performing snapshot operations may be implemented. Write requests for a particular data volume may be received for which a snapshot operation is in progress. A determination may be made as to whether a data chunk of the data volume modified as part of the write request has not yet been stored to a remote snapshot data store as part of the snapshot operation. For a data chunk that is to be modified and that has not yet been stored, the data chunk may be stored in a local in-memory volume snapshot buffer. Once the data chunk is stored in the in-memory volume snapshot buffer, the write request may be performed and acknowledged as complete. The data chunk may be sent to the remote snapshot data store asynchronously with regard to the acknowledgment of the write request.

Abstract: A storage system may implement dynamic configuration of data volumes. Client utilization of a data volume in a storage system may be tracked or monitored. Based on the utilization of the data volume, configuration recommendations to reconfigure the data volume according to data volume offerings may be determined. The data volume may be configured according to an authorized configuration recommendation. In some embodiments, these recommendations may be provided to a client and selection of the configuration recommendation to perform may be received. In some embodiments, a configuration recommendation may be automatically performed based on previously provided authorization to configure the data volume.

Abstract: A distributed system may implement opportunistic resource migration to optimize resource placement. Resources may be placed amongst different resource hosts of a distributed system. An evaluation of the current placement may be performed according placement criteria that improve placement of the resources at the distributed system. Based on the evaluation, the prospective migration of resources that exceed an improvement threshold may be identified as candidate resources to migrate. Migration for the candidate resources may be opportunistically performed. In some embodiments, a priority may be assigned to the candidate resources according to which the candidate resources are selected for performing migration.

Abstract: Write optimization for block-based storage performing snapshot operations may be implemented. Write requests for a particular data volume may be received for which a snapshot operation is in progress. A determination may be made as to whether a data chunk of the data volume modified as part of the write request has not yet been stored to a remote snapshot data store as part of the snapshot operation. For a data chunk that is to be modified and that has not yet been stored, the data chunk may be stored in a local in-memory volume snapshot buffer. Once the data chunk is stored in the in-memory volume snapshot buffer, the write request may be performed and acknowledged as complete. The data chunk may be sent to the remote snapshot data store asynchronously with regard to the acknowledgment of the write request.

Abstract: A block-based storage system may implement dynamic durability adjustment for page cache write logging. A rate of incoming write requests for data volumes maintained at a storage node may be monitored. Based, at least in part, on the rate of incoming write requests, a dynamic modification to a durability property for a data volume may be made, such as enabling page cache write logging the data volume or disabling write logging for the data volume. When incoming write requests are received, a determination may be made as to whether page cache write logging for a particular data volume is enabled. For write requests with disabled page cache write logging, the page cache may be updated and the write request may be acknowledged without storing a log record describing the update in a page cache write log.

Abstract: Generally described, systems and methods are provided for detecting locations of failures of network paths. The system collects information from a plurality of nodes and links in a network, aggregates the collected performance information across paths in the network, processes the aggregated performance information for detecting failures on the paths, and determines at least one location for network failures. In some aspects, processing the aggregated information may include determining the performance information on each of the nodes and links in the network. The performance information on each of the nodes and links may be determined by application and optimization of an objective function.

Abstract: Generally described, systems and methods are provided for detecting locations of failures of network paths. The system collects information from a plurality of nodes and links in a network, aggregates the collected performance information across paths in the network, processes the aggregated performance information for detecting failures on the paths, and determines at least one location for network failures. In some aspects, processing the aggregated information may include determining the performance information on each of the nodes and links in the network. The performance information on each of the nodes and links may be determined by application and optimization of an objective function.

Abstract: The estimated rate of work requests expected during a time period at a first block storage device, implemented at a particular server of a storage service, exceeds a provisioned rate of the first device. At a client-side component of the storage service, a different storage server is identified, at which the rate of work requests directed during the time period to a second block storage device is anticipated to be less than the provisioned rate of the second device. At least one admission control parameter of the first device is modified to enable the first storage server to accept work requests at a rate that exceeds the provisioned rate of the first device.

Abstract: A block-based storage system may implement page cache write logging. Write requests for a data volume maintained at a storage node may be received at a storage node. A page cache for may be updated in accordance with the request. A log record describing the page cache update may be stored in a page cache write log maintained in a persistent storage device. Once the write request is performed in the page cache and recorded in a log record in the page cache write log, the write request may be acknowledged. Upon recovery from a system failure where data in the page cache is lost, log records in the page cache write log may be replayed to restore to the page cache a state of the page cache prior to the system failure.

Abstract: A block-based storage system may implement dynamic durability adjustment for page cache write logging. A rate of incoming write requests for data volumes maintained at a storage node may be monitored. Based, at least in part, on the rate of incoming write requests, a dynamic modification to a durability property for a data volume may be made, such as enabling page cache write logging the data volume or disabling write logging for the data volume. When incoming write requests are received, a determination may be made as to whether page cache write logging for a particular data volume is enabled. For write requests with disabled page cache write logging, the page cache may be updated and the write request may be acknowledged without storing a log record describing the update in a page cache write log.

Abstract: A block-based storage system may implement reducing durability state for a data volume. A determination may be made that storage node replicating write requests for a data volume is unavailable. In response, subsequent write requests may be processed according to a reduced durability state for the data volume such that replication for the data volume may be disabled for the storage node. Write requests may then be completed at a fewer number of storage nodes prior to acknowledging the write request as complete. Durability state for the data volume may be increase in various embodiments. A storage node may be identified and replication operations may be performed to synchronize the current data volume at the storage node with a replica of the data volume maintained at the identified storage node.

Abstract: Various aspects of the performance of computing resources, such as storage volumes, are measured and used to train a probability model. The probability model is used in a query engine that is able to respond receive queries about a computing resource's state. The queries may specify a state of the computing resource and provide a set of measurements of the computing resource's performance. The query engine may use the probability model, which may be in the form of a contingency table, to provide information that indicates one or more most likely causes of the state.