Apache Storm

Apache storm

Apache Storm is a distributed real time big data processing system.

Apache Storm is scalable and fault tolerant - It employs Horizontal scaling. It is also known as scaling out.It is the ability to increase the capacity by adding multiple hardware and software entities so that they can work as a single unit.
It does n't need outage time as we connect a new hardware unit to the existing and administrators can increase the capacity on the fly. When servers are clustered the original server is scaled out. They will never have a single point of failure

 Vertical scalability, on the other hand, increases capacity by adding more resources, such as more memory or an additional CPU, to a machine. Scaling vertically, which is also called scaling up, usually requires downtime while new resources are being added and has limits that are defined by hardware.