1. A performance optimization system to optimize processing in a streaming system, the performance optimization system comprising: a data storage to store a dataflow directed acyclic graph comprising nodes and edges connecting the nodes, wherein the nodes process tuples and the edges send the tuples from one node to another node; a parameter determination module executed by a processor to calculate parameters for the nodes to minimize average latency for the tuples, wherein the parameters include batch size and a degree of parallelism (dop); and a parameter execution module to provide the parameters for the nodes to the streaming system, wherein the streaming system is to execute a dataflow for the dataflow directed acyclic graph according to the parameters for the nodes.