Apache Storm is used to handle very sensitive applications where even a delay of 1 second can mean huge losses. There are many companies using Storm for fraud detection, building recommendation engines, triggering suspicious activity, and so on. Storm is stateless; it uses Zookeeper for coordinating purposes, where it maintains important metadata information.
Apache Storm is a distributed real-time processing framework which has the ability to process a single event at a time with millions of records being processed per second per node. The streaming data can be bounded or unbounded; in both situations Storm has the capability to reliably process it.
