The internet of things (IoT) has found a wide range of applications in modern times. IoT can be defined as follows:
IoT devices are connected to the internet; they sense and communicate. They are equipped with different types of sensors that collect the data they observe and transmit it over the internet. This data can be stored, analyzed, and often acted upon in near-real time. The number of such connected devices is projected to rise rapidly; according to Wikipedia, there will be an estimated 30 billion connected devices by 2020. Since each device can capture the current value of a metric and transmit it over the internet, this can result in massive amounts of data.
A plethora of different types of sensors have emerged in recent times for temperature, humidity, light, motion, and airflow; these can be used in different types of applications. Each sensor can be programmed to take a current reading and send it over the internet.
Let's consider the following diagram for our understanding:
Figure 10.1 provides an idea of the high-level architecture of the system that we will discuss in this chapter. The left-hand side of the figure depicts various types of devices equipped with sensors. These devices are capable of capturing different metrics and sending them over the internet for long-term storage and analysis. In the right half of the figure, you see the server-side components on the other side of the internet. The server-side components primarily consist of the Elastic Stack.
In this chapter, we will look at an application in which we want to store and analyze sensor data from two types of sensors: temperature and humidity sensors, placed at various locations.
Sensors can be deployed across multiple sites or locations, with each site connected to the internet as shown in the figure. Our example demonstrates two types of sensors, temperature, and humidity, but the application can be extended to support any kind of sensor data.
We will cover the following points about the system in this section:
- Understanding the sensor-generated data
- Understanding the sensor metadata
- Understanding the final stored data
Let's go deep into the application by understanding each topic one by one.