FESpaces

ConstantFESpace(
  model::DistributedDiscreteModel; 
  constraint_type=:global, 
  kwargs...
)

Distributed equivalent to ConstantFESpace(model;kwargs...).

With constraint_type=:global, a single dof is shared by all processors. This creates a global constraint, which is NOT scalable in parallel. Use at your own peril.

With constraint_type=:local, a single dof is owned by each processor and shared with no one else. This space is locally-constant in each processor, and therefore scalable (but not equivalent to its serial counterpart).