@clearblade/one-way-sync

Overview

This repository provides modules for assisting in one-way sync from ClearBlade edge to ClearBlade platform. This approach is useful if you have a single ClearBlade collection used to store sensor or device data from multiple edges. This library will track the connected/disconnected status of the edge to the platform, and while connected will forward any MQTT messages received on the provided topics to the platform via message relay. If the edge is disconnected for any reason, incoming MQTT messages will be stored in a collection. As soon as the edge is reconnected, all messages in the collection will be forwarded to the platform.

From there, you will simply need to create a stream service on your platform in order to do any needed processing and storing of these messages.

Installation

npm i --save @clearblade/one-way-sync

Prerequisites

This package must be configured with the following assets:

• The ClearBlade library must be imported as a dependency of each code service.
• A shared cache must be created in order to allow for checking if an edge is connected or disconnected from the platform. The default name is edgeDataSharedCache but the name can be configured with the cacheName parameter. A TTL of 1 hour is recommended.
• A collection must be created in order to store a queue of messages if an edge is disconnected from the platform. The default name is edge_relay_cache but the name can be configured with the cacheName parameter. This collection will require the below columns:

Column Name	Type
topic	string
payload	string
timestamp	timestamp

• Two triggers must be created in order to toggle the edge connected/disconnected variable in the shared cache.
  • A PlatformConnectedOnEdge trigger must be configured with the Edge Connected Service
  • A PlatformDisconnectedOnEdge trigger must be configured with the Edge Disconnected Service

Usage

The modules within this package must be imported into and configured from a code service.

Edge Message Relay

import relay from "@clearblade/one-way-sync/edge/edge-message-relay";

function edgeMessageRelay(req: CbServer.BasicReq, resp: CbServer.Resp) {
  relay({
    req: req,
    resp: resp,
    topics: ['one', 'two'],
    cacheName: 'edgeDataSharedCache', // optional cache name
    collectionName: 'edge_relay_cache' // optional collection name
  });
}

// @ts-ignore
global.edgeMessageRelay = edgeMessageRelay;

Edge Connected Service

import onConnect from "@clearblade/one-way-sync/edge/edge-disconnected";

function edgeConnected(req: CbServer.BasicReq, resp: CbServer.Resp) {
  onConnect({
    req: req,
    resp: resp,
    cacheName: 'edgeDataSharedCache', // optional cache name
    collectionName: 'edge_relay_cache' // optional collection name
  });
}

//@ts-ignore
global.edgeConnected = edgeConnected;

Edge Disconnected Service

import onDisconnect from "@clearblade/one-way-sync/edge/edge-disconnected";

function edgeDisconnected(req: CbServer.BasicReq, resp: CbServer.Resp) {
  onDisconnect({
    req: req,
    resp: resp,
    cacheName: 'edgeDataSharedCache', // optional cache name
    collectionName: 'edge_relay_cache' // optional collection name
  });
}

//@ts-ignore
global.edgeDisconnected = edgeDisconnected;

TODO

1. add one-way sync from platform to edge