Databases Reference
In-Depth Information
Figure 1-1. A simple topology
Now imagine easily defining the level of parallelism for each bolt and spout across the
whole cluster so you can scale your topology indefinitely. Amazing, right? Although
this is a simple example, you can see how powerful Storm can be.
What are some typical use cases for Storm?
Processing streams
As demonstrated in the preceding example, unlike other stream processing sys-
tems, with Storm there's no need for intermediate queues.
Continuous computation
Send data to clients continuously so they can update and show results in real time,
such as site metrics.
Distributed remote procedure call
Easily parallelize CPU-intensive operations.
The Components of Storm
In a Storm cluster, nodes are organized into a master node that runs continuously.
There are two kind of nodes in a Storm cluster:
master node
and
worker nodes
. Master
node run a daemon called
Nimbus
, which is responsible for distributing code around
the cluster, assigning tasks to each worker node, and monitoring for failures. Worker
