Explaining oneM2M 'Notifications' via 'Recipes'
We recently wrote about different pathways for learning to use oneM2M, including Recipe articles. For any given feature, Recipes explain the business process rationale and then provide technical implementation examples. This post announces an addition to the Recipes library focusing on the process of ‘monitoring operations’ and using call-flow and code examples to illustrate its application.
In the oneM2M world, there are two types of ‘monitoring applications.’ As illustrated, a system architect can monitor data from a sensor for the purposes of triggering an action in a decision-making application. The second possibility applies to the internal behavior of an IoT system. This allows a system developer to monitor how Application Entities (AEs) access resources, whether resources are being correctly accessed, or whether applications are misbehaving. Notifications about conditions such as these helps developers to diagnose faulty or undesirable patterns of operation and to fine-tune system performance.
When a monitoring application periodically queries a sensor to check for changes, this introduces an overhead in system operations. The overhead scales with system size; imagine several decision-making applications constantly polling an array of sensors and connected devices. Use of a subscription-notification technique reduces that overhead.
An example of how that works in an IoT system involves a data-processing application that would ‘subscribe’ to a sensor. The application (AE-2) would only receive updates when that sensor (AE-1) had a new reading to share. The subscription-notification function resides in the middleware, or IoT platform, between application and sensor. It is a standardized function in oneM2M’s technical framework.
To learn more, here is an explanation of how notifications inform entities about changes to resources in a oneM2M system. Next, this pair of links introduce the rationale for monitoring operations, and how to implement the monitoring of request operations.
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