Abstract: In a stream computing application shutdown, a shutdown message is received by a source operator of the stream computing application. In response, the source operator stops acquiring data from external sources, sends any cached data to an output queue of the source operator, sends the shutdown message to the output queue of the source operator, and sends the cached data and shutdown message to an input queue of another operator in the stream computing application. The source operator then terminates. In response to receiving the shutdown message, the other operator completes the processing of data in its input queue and sends any outputs from the processing of the data in its input queue to one or more output destinations. The other operator then terminates. In this manner, a stream computing application may be shut down while ensuring that any already inputted data is processed to completion, thus avoiding data loss.

Abstract: In a stream computing application shutdown, a shutdown message is received by a source operator of the stream computing application. In response, the source operator stops acquiring data from external sources, sends any cached data to an output queue of the source operator, sends the shutdown message to the output queue of the source operator, and sends the cached data and shutdown message to an input queue of another operator in the stream computing application. The source operator then terminates. In response to receiving the shutdown message, the other operator completes the processing of data in its input queue and sends any outputs from the processing of the data in its input queue to one or more output destinations. The other operator then terminates. In this manner, a stream computing application may be shut down while ensuring that any already inputted data is processed to completion, thus avoiding data loss.

Abstract: A method for sorting and merging data from at least two sources may include providing a multi-state merge of queues from a first input queue and a second input queue to a merged output, responsive to states of the first and second input queues, setting the state of the first input queue; preventing merging of the first input queue with the non-empty second input queue while the state of the first input queue is empty waiting; and merging the first input queue with the non-empty second input queue responsive to the state of the first input queue being active or ignore, or the wait duration time being exceeded, or in response to a startup command.