It looks like the instructions for the riak protocol buffers client has a typo. Running the start_link in the shell will result in a hiccup with the port they specify.

> {ok, Pid} = riakc_pb_socket:start_link("", 8087).
** exception exit: {tcp,econnrefused}

The reason is that in the app.config for the primary riak node (dev1 if you follow the instructions), the port is set to 8081. When connecting via riakc, it’s necessary to connect to the right port. The protocol buffers interface runs on its own port, which is 8081.

{pb_port, 8081 },

Changing the port should rectify the problem.

> {ok, Pid} = riakc_pb_socket:start_link("", 8081).
> riakc_pb_socket:ping(Pid).