Some embodiments provide a method for assigning different service path identifiers to each of a set of different service paths along each of which a same set of service operations are performed on a set of packets. The method retrieves an available service path identifier from an identifier storage that stores service path identifiers for multiple service paths. The method generates a set of proposed service path identifiers based on the retrieved available service path identifier and the number of service paths in the set of service paths. The method performs a write operation on the identifier storage based on the set of proposed service path identifiers, and based on a determination that the write operation was successful, assigns the set of proposed service path identifiers to the set of service paths. Based on the set of service path identifiers, the method forwards the set of packets along the set of service paths.