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