  Using a holographic method, we further investigate the relaxation towards the
hydrodynamic regime of a boost-invariant non-Abelian plasma taken
out-of-equilibrium. In the dual description, the system is driven
out-of-equilibrium by boundary sourcing, a deformation of the boundary metric,
as proposed by Chesler and Yaffe. The effects of several deformation profiles
on the bulk geometry are investigated by the analysis of the corresponding
solutions of the Einstein equations. The time of restoration of the
hydrodynamic regime is investigated: setting the effective temperature of the
system at the end of the boundary quenching to $T_{eff}(\tau^*)=500$ MeV, the
hydrodynamic regime is reached after a lapse of time of ${\cal O}$(1 fm/c).
