Article
Dmitry Maslennikov · Oct 19 3m read

Monitor production with Node-RED

I would like to demonstrate how you can create monitoring of Production with Node-RED, and get a dashboard like this.

First of all, you would need to run Node-RED. It's possible to install it locally or, run it with Docker. Official Docker images for Node-RED based on Alpine, and may not work correctly with IRIS, yet. So, please use image caretdev/node-red

docker run -it -p 1880:1880 -v myNodeREDdata:/data --name mynodered caretdev/node-red

After the start of the container, it will be available by link http://localhost:1880/

Let's have a look at how it looks like. The field in the middle is used to construct flows by drag-n-drop nodes from the left side. On the right side, some additional control over it, such as, quick access to the items, and debugging.

Node-RED is extendable, and we can install any new types of nodes and can find them through Palette, which can be accessed via the menu.

And we will need, to install a node, which gives access to InterSystems, just search for intersystems there and press install.

After install it will appear on the left side, in section Storage. By double click, we can open settings for the particular instance of the node. 

It is possible to have many instances of InterSystems IRIS nodes there, which will use the same settings to the server, so, these settings have to be configured once.

We have the node, which will do the work, then we need some node, which will provide the task, what exactly to do. InterSystems IRIS node accepts SQL Query passed as a message in property topic. And the simplest way to produce this message in Node-RED is with the node function . These types of nodes, executes JavaScript code, it gets the messages in msg variable, can modify it and return, so, it will be sent to the next node. For the demo, we don't need anything in input, we just generate a simple message with a simple SQL query in the topic.

It's not enough, to get it working. We need a way to send an event that will trigger the chain of nodes. In this simple case, we can use node inject . The settings for this type of nodes allows generating a message as well, and most importantly it can be configured to inject these messages with some interval

The last thing left is visualization. Node-RED has another installable package named node-red-dashboard, which provides a bunch of nodes and the capability to create Material-design based dashboards

Dashboard example

Our simple SQL query returns only one number, with the number of messages sent. So, we may use a Gauge widget or just a Text widget. Both of these widgets expects some number in msg.payload but intersystems IRIS node returns more than just a number, and we need one more function node, which will help to convert the query result to the expected format.  Debug node, may help in understanding how messages look like. 

And finally, we can link all the nodes together, deploy them and test it with the small button on Inject node, to manually inject the message.

The dashboard can be found in the menu. And we will see there something like this

The flow for the first picture above is a bit bigger.

This demo is available in the GitHub repo, and can be run with docker-compose.

And please vote for the project on the Contest

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In addition to the demo described in the article, there is a simple flow for demonstration work with SQL.

And another demo, is mostly just for fun, to see how it's possible to create even some UI there.

With quite a complex flow like this

It was possible to create an interface like this

It allows, to create a new table in IRIS, and add some fields. For sure, too far from production use, but as a proof-of-concept.

All those demos are available in the repo.

While Node-RED has lots of interesting nodes out of the box, it may make it useful in tasks where some features are not available in IRIS.

And it's a low-code tool, so, just drag-n-drop and connect nodes, with some configuration.

Very nice integration PoC, showing the power of using the Node.js ecosystem. Combining mainstream Node.js tools & modules with IRIS allows you to create very powerful applications without having to reinvent the wheel. smiley