In this tutorial we present the results of recent research about
the cloud enablement of data streaming systems. We illus-
trate, based on both industrial as well as academic prototypes,
new emerging uses cases and research trends. Specifically,
we focus on novel approaches for (1) scalability and (2) fault
tolerance in large scale distributed streaming systems. In
general, new fault tolerance mechanisms strive to be more
robust and at the same time introduce less overhead. Novel
load balancing approaches focus on elastic scaling over hun-
dreds of instances based on the data and query workload.
Finally, we present open challenges for the next generation
of cloud-based data stream processing engines.