LIN Q ▁data - parallel ▁processing ▁frameworks ▁are ▁available ▁in ▁source ▁form ▁at ▁GitHub . ▁ ▁Over view ▁Microsoft ▁made ▁several ▁preview ▁releases ▁of ▁this ▁technology ▁available ▁as ▁add - ons ▁to ▁Windows ▁H PC ▁Server ▁ 2 0 0 8 ▁R 2 . ▁ ▁An ▁application ▁written ▁for ▁D ry ad ▁is ▁mode led ▁as ▁a ▁directed ▁a cyc lic ▁graph ▁( DA G ). ▁The ▁D AG ▁defines ▁the ▁data flow ▁of ▁the ▁application , ▁and ▁the ▁vertices ▁of ▁the ▁graph ▁defines ▁the ▁operations ▁that ▁are ▁to ▁be ▁performed ▁on ▁the ▁data . ▁The ▁" comput ational ▁vertices " ▁are ▁written ▁using ▁sequ ential ▁construct s , ▁de void ▁of ▁any ▁conc urrency ▁or ▁mut ual ▁ex clusion ▁semantics . ▁The ▁D ry ad ▁runtime ▁parallel izes ▁the ▁data flow ▁graph ▁by ▁distrib uting ▁the ▁computational ▁vertices ▁across ▁various ▁execution ▁engines ▁( which ▁can ▁be ▁multiple ▁processor ▁cores ▁on ▁the ▁same ▁computer ▁or ▁different ▁physical ▁computers ▁connected ▁by ▁a ▁network , ▁as ▁in ▁a ▁cluster ). ▁Sch ed uling ▁of ▁the ▁computational ▁vertices ▁on ▁the ▁available ▁hardware ▁is ▁handled ▁by ▁the ▁D ry ad ▁runtime , ▁without ▁any ▁explicit ▁inter vention ▁by ▁the ▁developer ▁of ▁the ▁application ▁or ▁administrator ▁of ▁the ▁network . ▁The ▁flow ▁of ▁data ▁between ▁one ▁computational ▁vertex ▁to ▁another ▁is ▁implemented ▁by ▁using ▁communication ▁" ch annels " ▁between ▁the ▁vertices , ▁which ▁in ▁physical ▁implementation ▁is ▁realized ▁by ▁TCP / IP ▁streams , ▁shared ▁memory ▁or ▁temporary ▁files . ▁A ▁stream ▁is ▁used ▁at ▁runtime ▁to