  Using 137,562 quasars in the redshift range $2.1\leq z\leq3.5$ from the Data
Release 11 (DR11) of the Baryon Oscillation Spectroscopic Survey (BOSS) of
Sloan Digital Sky Survey (SDSS)-III, the BOSS-SDSS collaboration estimated the
expansion rate $H(z=2.34)=222\pm7$ km/s/Mpc of Universe, and reported that this
value is in tension with the predictions of flat $\Lambda$CDM model at around
2.5$\sigma$ level. In this paper, we briefly describe some attempts made in the
literature to relieve the tension, and show that the tension can naturally be
alleviated in non-flat $\Lambda$CDM model with positive curvature. We also
perform the observational consistency check by considering the constraints on
the non-flat $\Lambda$CDM model from Planck,WP and BAO data. We find that the
non-flat $\Lambda$CDM model constrained with Planck+WP data fits better to the
line of sight measurement $H(z=2.34)=222\pm7$ km/s/Mpc, but only at the expense
of still having a poor fit to the BAO transverse measurements.
