A bicycle front derailleur includes a fixing member, a chain guide and a linkage mechanism. The tunnel junction includes a layer of first conductivity type and a layer of second conductivity type, both thinner than a layer of first conductivity type and a layer of second conductivity type surrounding the first active region. Among various other aspects of the present invention, when there is a change, such as a server failure, that prompts a recovery, the recovery can be performed in parallel among the nodes.