  We discuss methods to extract decay constants, meson masses and gluonic
observables in the presence of open boundary conditions. The ensembles have
been generated by the CLS effort and have 2+1 flavors of O(a)-improved Wilson
fermions with a small twisted-mass term as proposed by L\"uscher and Palombi.
We analyse the effect of the associated reweighting factors on the computation
of different observables.
