Method, system and computer program product for performing an operation, including providing a plurality of processing elements comprising one or more operators, the operators configured to process streaming data tuples, establishing an operator graph of multiple operators, the operator graph defining at least one execution path in which a first operator is configured to receive data tuples from at least one upstream operator and transmit data tuples to at least one downstream operator, providing each operator a buffer configured to hold data tuples requiring processing receiving a plurality of data tuples in a buffer associated with an operator, the data tuples comprising at least one attribute, determining a backlog exists in the first buffer, selecting at least one data tuple from the first buffer, examining an attribute of the selected data tuples to identify a candidate tuple, and performing a second operation on the candidate tuple.