  We define and study a class of resources allocation processes where $gN$
agents, by repeatedly visiting $N$ resources, try to converge to optimal
configuration where each resource is occupied by at most one agent. The process
exhibits a phase transition, as the density $g$ of agents grows, from an
absorbing to an active phase. In the latter, even if the number of resources is
in principle enough for all agents ($g<1$), the system never settles to a
frozen configuration. We recast these processes in terms of zero-range
interacting particles, studying analytically the mean field dynamics and
investigating numerically the phase transition in finite dimensions. We find a
good agreement with the critical exponents of the stochastic fixed-energy
sandpile. The lack of coordination in the active phase also leads to a
non-trivial faster-is-slower effect.
