def _get_ps_strategy(job_name, ps_specs):
    """ Returns the param server strategy to use """
    if job_name != 'worker' or len(ps_specs) <= 1:
        return None
    from diplomacy_research.utils.tensorflow import GreedyLoadBalancingStrategy, byte_size_load_fn
    return GreedyLoadBalancingStrategy(num_tasks=len(ps_specs), load_fn=
        byte_size_load_fn)
