1. A system for processing a stream of tuples, comprising: a plurality of compute nodes having a plurality of processing elements to receive a stream of tuples, the plurality of processing elements operating on one or more computer processors, each processing element of the plurality of processing elements having one or more stream operators; a stream manager, the stream manager configured to monitor the plurality of compute nodes and to determine whether a processing condition exists in the plurality of compute nodes; and a compiler, the compiler configured to receive a first compiler directive specifying an operator sub-graph included in the plurality of compute nodes, the operator sub-graph including one or more processing elements of the plurality of processing elements, the compiler configured to receive a second compiler directive identifying a first processing element of the plurality of processing elements, the first processing element configured to bypass the operator sub-graph by transmitting one or more predicted output tuples to a second processing element of the plurality of processing elements, in response to determining that a processing condition exists in the plurality of compute nodes.