We propose an effective switch-controller mapping scheme for distributed controller architectures in software defined networks. Our scheme maps a switch to multiple controllers and distributes flow setup requests among them to minimize flow setup time, satisfying the resilience constraint, which requires that a specified fraction of setup requests at each switch is not affected upon a controller failure. We develop an optimization formulation for the problem and compare our scheme against the single controller mapping. The results show that our scheme reduces flow setup time, provides better fairness among switches and that it is more stable against dynamic traffic fluctuations.