1. A computer-implemented method for data integration on retargetable engines in a networked environment, the computer-implemented method comprising: receiving a first request specifying to execute a data flow model in the networked environment and based on a first engine property selected from execution efficiency and fault tolerance, wherein the networked environment includes a plurality of data processing engines of different types, wherein each of the plurality of data processing engines has a different set of properties, wherein the data flow model includes a plurality of data flow objects and represents one or more data integration operations; upon determining that a first data processing engine has a highest capability of the first engine property among the plurality of data processing engines, commencing execution of the data flow model using the first data processing engine, responsive to the first request; subsequent to commencing execution of the data flow model using the first data processing engine, receiving a second request specifying to execute the data flow model in the networked environment based on a second engine property selected from execution efficiency and fault tolerance, different from the first engine property; and upon determining, by operation of one or more computer processors, that a second data processing engine, different from the first data processing engine, has a highest capability of the second engine property among the plurality of data processing engines, suspending execution of the data flow model using the first data processing engine and resuming execution of the data flow model using the second data processing engine, wherein execution of the data flow model is retargeted from the first data processing engine to the second data processing engine.