Abstract: Generally described, one or more aspects of the present application correspond to techniques for dynamically aggregating data records from separate sources. The data merging process can be implemented by an aggregation computing resource that uses a lockstep paging system to query multiple database platforms for the same range of records, merges the records returned by the database platforms, and continues identifying a next range of records for which the database platforms should be queried until all records have been merged into a single listing. These techniques can be used to unify records during a database migration process.

Abstract: Techniques for maintaining a graph associated with snapshots are described. In some embodiments, a snapshot service maintains one or more graphs in a graph database. The snapshot service maintains a graph data structure having a plurality of vertices corresponding to a plurality of snapshots, wherein each vertex of the plurality of vertices is at least a parent to or a child of another vertex, and each child vertex of the plurality of vertices comprises a value representing a number of chunks of data referenced in the corresponding snapshot corresponding to of the child vertex that are not referenced in the snapshot corresponding to the parent vertex of the child vertex. The snapshot service further determines a total number of unique chunks of data attributed to the plurality of snapshots based at least in part on traversing the graph data structure.

Abstract: A metrics subsystem determines the utilization of computing resources of server computer systems. The metrics subsystem may obtain metadata associated with a plurality of computing resources used to provide a service. The metrics subsystem determines a set of references to data included in the metadata and aggregates references of the set of references to determine utilization of computing resources and provides the utilization to a metering service.