In this recipe, we will configure in-transit encryption for securing the transfer of data between nodes during the shuffle phase. The mapper output is consumed by reducers, which can run on different nodes, so to secure the transfer channel, we secure the communication between Mappers and Reducers. We will be securing the RPC communication channel as well, although it induces a slight overhead and must be setup only if it is absolutely necessary.
To complete the recipe, the user must have completed the previous Configure SSL in Hadoop recipe. We will be extending the configuration already set up in that section by adding a few more options.