Читать книгу Fog Computing - Группа авторов - Страница 62

In general, fog nodes have limited resources to serve tenants because they are fundamentally the independent network gateway devices that do not interconnect with one another in a short range like the server pools in the cloud. In other words, introducing computational scalability in MFC faces the network latency challenge. Commonly, providers of fog servers may manage multiple fog servers that are interconnected vertically within the hierarchy or are interconnected horizontally in a peer-to-peer manner. However, since the primary objective of fog servers in MFC is to serve the tenant-side clients, the distances between the fog servers are rarely within the range that is capable of achieving ultra-low latency. Therefore, the classic cloud-based scalability scheme is incompatible in MFC and hence, scalability becomes an unsolved challenge, especially for mFog environments. In order to address the challenge in scalability, the developers may consider developing a hybrid framework that integrates opportunistic computing, SDN, and context-aware software architecture toward enabling an adaptive fog service topology that can be orchestrating the fog servers in a highly dynamic manner.