Residual dependencies

As far as reasonably possible residual dependencies should be avoided. For example, systems which rely on proxy chains for forwarding messages decrease the availability of the system as a whole because the failure of any node may mean that other processes are uncontactable although running and accessible. In addition, noting that remote communication is significantly more costly than local communication, residual dependencies (which are inherently remote) usually imply a degree of inefficiency. In certain cases (<#2735#> e.g.<#2735#> requiring input from the original host's keyboard) this is unavoidable.