A usage analysis service that obtains session events from application instances, updates usage metrics for the application instances according to the session events, and stores or updates aggregated usage metrics for each application according to the session events. Updates for the instance usage metrics may be partitioned according to instance identifier, collected in batches, and applied to respective instance records in an instances table by one or more instance update nodes. Updates for the aggregated usage metrics may be partitioned according to application identifier, collected in batches, processed to combine multiple updates, and applied to respective aggregate records in an application usage table by multiple application usage update nodes. The system may provide an interface that retrieves aggregated usage metrics from the application usage table and presents application usage information for the applications to consumers.