Observability

The Observability capability is enabled by the following components of Sunbird Observ-

Telemetry Service - Telemetry Service is a microservice that is capable of processing one or more events received from clients. Developed in NodeJS, telemetry service has processed more than 2 billion events per day.

What is Telemetry?

The word ‘Telemetry’ is derived from its Greek etymological roots, tele - remote and metron - measure.

Telemetry V3 Event Structure

All events follow a common data structure, though the event data structure (“edata”) differs for each event. The complete data structure is as follows:

{
 // About the event
 "eid": , // Required. TODO: Shall we rename it to "verb" ?? 
 "ets": , // Required. Epoch timestamp of event (time in milli-seconds. For ex: 1442816723)
 "ver": , // Required. Version of the event data structure, currently "3.0"
 "mid": , // Required. Unique message ID. Used for deduplication, replay and update indexes
 
 // Who did the event
 "actor": { // Required. Actor of the event.
   "id": , // Required. Id of the actor. For ex: uid incase of an user
   "type":  // Required. User, System etc.
 },
 
 // Context of the event
 "context": { // Required. Context in which the event has occured.
   "channel": , // Required. Channel which has produced the event
   "pdata": { // Optional. Producer of the event
     "id": , // Required. unique id assigned to that component
     "pid": , // Optional. In case the component is distributed, then which instance of that component
     "ver":  // Optional. version number of the build
   },
   "env": , // Required. Unique environment where the event has occured.
   "sid": , // Optional. session id of the requestor stamped by portal
   "did": , // Optional. uuid of the device, created during app installation
   "cdata": [{ // Optional. correlation data
     "type":"", // Required. Used to indicate action that is being correlated
     "id": "" // Required. The correlation ID value
   }],
   "rollup": { // Optional. Context rollups
     "l1": "",
     "l2": "",
     "l3": "",
     "l4": ""
   }
 },
 // What is the target of the event
 "object": { // Optional. Object which is the subject of the event.
   "id": , // Required. Id of the object. For ex: content id incase of content
   "type": , // Required. Type of the object. For ex: "Content", "Community", "User" etc.
   "ver": , // Optional. version of the object
   "rollup": { // Optional. Rollups to be computed of the object. Only 4 levels are allowed.
   	"l1": "",
     "l2": "",
     "l3": "",
     "l4": ""
   }
 },
 
 // What is the event data
 "edata": {} // Required.
 
 // Tags
 "tags": [] // Optional. Encrypted dimension tags passed by respective channels
}

Note:

All events have the same structure with only differences in edata structures.
All events have unique event codes i.e., (IDs).
All events are as per platform schema

For more information about Telemetry services please click

Telemetry Spec

Start - This method initializes the capture of telemetric data associated with the start of user's action
Impression - This method is used to capture telemetry for user visits to a specific page.
Interact - This method is used to capture user interactions on a page. For example, search, click, preview, move, resize, configure
Assess - This method is used to capture user assessments that happen while playing content.
Response - This method is used to capture user responses. For example; response to a poll, calendar event, or a question.
Interrupt - This method is used to capture interrupts triggered during user activity. For example; mobile app sent to the background, call on the mobile, etc.
Feedback - This method is used to capture user feedback
Share - This method is used to capture everything associated with sharing. For example; Share content, telemetry data, link, file, etc.
Audit - This method is used to log telemetry when an object is changed. This includes life-cycle changes as well
Error - This method is used to capture when users face an error
Heartbeat - This method is used to log telemetry for heartbeat events to denote that the process is running
Log - This method is used to capture generic logging of events. For example; capturing logs for API calls, service calls, app updates, etc.
Search - This method is used to capture the search state i.e. when a search is triggered for content, item, assets, etc.
Metrics - This method is used to log telemetry for service business metrics
Summary - This method is used to log telemetry summary event
Exdata - This method is used as a generic wrapper event to capture encrypted or serialized data
End - This method is used to capture closure after all the activities are completed