AWS Greengrass

 AWS IoT Greengrass is software functionality that connects cloud capabilities to local devices. This facilitates devices in data collection and analytics closer to the source (devices on IoT), quicker response time, and secure communication over local networks, even when they are not connected to the cloud. 

These devices are collectively known as a Greengrass group. 

Greengrass groups are configured and defined from the cloud but do not “need” the cloud to connect and communicate with each other.

In AWS IoT Greengrass, devices securely communicate over a local network and exchange data without a connection to the cloud. AWS IoT Greengrass achieves this through a local pub/sub message manager that can buffer messages even while there is no connectivity, thus preserving messages to and from the cloud.

Building an AWS Greengrass:

Step 1: Establish a Greengrass core:

Every group needs a Greengrass core to function. Central to this group is a physical device, on which the Greengrass core software is installed. The core software securely connects the device to the AWS. There can be only one core to a group.

Step 2: Building a group:

Once the core is established, we can continue to add devices to the group that are themselves on the cloud, or other devices which are AWS IoT provisioned, or AWS Lambda functions – which are essentially simple programs that can process or respond to data. Presently, a Greengrass group can contain up to 200 devices. A device can be a member of up to 10 groups.

Step 3: Code, the group:

Once deployed, the core and devices can communicate, even without a connection. IoT vs. AWS IoT Greengrass: The IoT (Internet of things) is a network of connected devices called “Things” that are connected to a cloud server (a fit-bit or a fridge or a thermal sensor could be a “thing”).

 Data aggregated from these things on to the cloud server, data could be monitored in real-time and react/respond immediately.