Abstract: A method for distributively storing a data object on a data storage system includes determining a layout map ID and associating the layout map ID with the data object. The layout map ID is used in determining a layout map, and the layout map is used in determining a layout given a current configuration of the data storage system. The data object is fragmented into data fragments and parity fragments, and the data fragments and parity fragments are distributively stored on data storage system in accordance with the layout.

Abstract: A method includes determining a garbage collection list for a data storage structure of a node in a data storage system, the garbage collection list including one or more layout map identifiers (IDs) for garbage collection. A data fragment stored on the data storage structure is located at a first location and a layout map ID associated with the data fragment is determined. A determination is made whether the layout map ID associated with the data fragment matches a layout map ID for garbage collection in the garbage collection list. If the layout map ID associated with the data fragment matches a layout map ID for garbage collection in the garbage collection list, a determination is made whether the data fragment is present at a second location on the data storage system. If the data fragment is present at a second location on the data storage system, the data fragment at the first location is determined to be a garbage fragment and deleted from the data storage system.

Abstract: A method for recovery of data objects on a data storage system includes determining a list of layout map IDs that place data objects on a node of a data storage system. For each layout map ID, a list of object IDs associated with each of the data objects assigned the layout map ID is determined. For each object ID, a list of data object fragments associated with the object ID is determined. A determination is made whether each of the data object fragments is present on the node. If a data object fragment is not present on the node, the data object fragment is reconstructed on the data storage system. The method can be automatically implemented by each of one or more operational nodes of a distributed data storage system at configured time intervals, and/or upon the operational loss of a data storage structure of a node, or a node.

Abstract: A node availability management system includes a president node which includes a message queue to store a message, a decision engine configured to generate an operation based on the message, where said operation includes a plurality of atomic actions arranged in a dependency graph, an executor configured to execute the operation by executing the plurality of atomic instructions in the dependency graph, and a slave node operatively connected to the president node, where the executor offloads the execution of at least one of the plurality of atomic actions to the slave node.