A method in the embodiments of the application includes: obtaining, by a first network element, first data that corresponds to a service flow and that is on each of at least two network elements, where the first data that corresponds to the service flow and that is on each of the network elements includes a first identifier; obtaining, by the first network element based on the first identifier and the first data that corresponds to the service flow and that is on each of the network elements, second data that corresponds to the service flow, where the second data includes at least the first data that corresponds to the service flow and that is on each of the network elements.