  We discuss the single-parton and double-parton scattering (SPS or DPS)
effects in four-jet production at the LHC. The calculations of both
single-parton and double-parton scattering components are done in the
high-energy (or $k_{T}$)-factorization approach. Here we follow our recent
developments of relevant methods and tools. The calculations are performed for
kinematical situations relevant for two experimental measurements (ATLAS and
CMS) at the LHC. We compare our results to those reported by the ATLAS and CMS
collaborations for different sets of kinematical cuts. A special attention is
given to the optimization of kinematical conditions in order to enhance the
relative contribution of DPS in four-jet sample. Several differential
distributions are calculated and carefully discussed in the context of recent
and future searches for DPS effects at the LHC. The dependences of the relative
DPS amount is studied as a function of rapidity of jets, rapidity distance, and
various azimuthal correlations between jets. The regions with an enhanced DPS
contribution are identified.
