dataRT Python Library

About

What does dataRT do?

dataRT is a drop-in replacement for the InfluxDBClient which writes data to InfluxDB while simultaneously echoing the points to a WebSocket. This allows you to view the data in real-time in a web browser or other client.

What scenario would I need this for?

dataRT is designed to be used where the InfluxDBClient is already being used but constantly querying InfluxDB does not provide adequate real-time access to your data. By creating a client webpage you can display the data in real time while simultaneously recording the points in InfluxDB for examination at a later date.

What if I don't want to use InfluxDB?

No problem! InfluxDB is not a requirement to use dataRT. If the influx_url argument is set to None, dataRT will echo the data to a WebSocket, but not attempt to send data to an InfluxDB instance.

Installation

PyPi

> pip install dataRT

Setuptools

> python setup.py install

Usage

Single-Thread Application

If you are constrained for resources, you can use the CoreClient object.

It is highly recommended that you monkey-patch using gevent when using this technique.

To start, import the CoreClient:

from dataRT import CoreClient

Then create a client:

client = CoreClient(influx_url=None, debug=True)

The CoreClient takes these arguments, all are optional:

Define a "action" function then start the dataRT loop. This function will be constantly called as the dataRT runs through its maintenance loop:

def action(possible_arg, possible_kwarg=100):
    print(possible_arg)
    print(possible_kwarg)

client.run_in_loop(action, 'possible_arg', possible_kwarg=1000)

Once run_in_loop is called, the client blocks until client.stop() is called or the program exits.

Available client functions:

Available client properties:

Multi-Process Application

If you need more reliability or want to avoid your code possibly blocking dataRT background tasks, use the Client object.

To start, import the Client:

from dataRT import Client

Then create a client:

client = Client(influx_url=None, debug=True)

The Client takes these arguments, all are optional:

Once the client is defined, you can start it:

client.start()

Once start is called, the client will start in another process and continue serving until client.stop() is called or the program exits.

Available client functions:

Where is my WebSocket?

The WebSocket associates itself with the client route on the WebSocket path: ws:\\<host>:<port>\<ws route>\client.

For the default settings, this would be ws:\\0.0.0.0:8080\ws\client

Examples

Examples can be found in the examples directory.

Library Usage

• gevent_example.py shows how to integrate the dataRT client in a single-threaded application using gevent. (Note: using this method you must be careful not to block the process from running maintenance for the WebSocket connection otherwise you may encounter issues)
• multiprocess_example.py shows how to use the dataRT client as a drop-in-place replacement for the InfluxDBClient by leveraging a separate process (Note: This does consume more system resources, use the gevent method if you are working in a resource-constrained environment)

HTML/JS

• view_data.html uses basic jQuery to write each piece of data that is received onto the page in a table.
• plot_data.html uses the Chart.js library to plot each point onto a line graph in real time.

Licensing

This project is licensed under the MIT license. No warranty is provided, use at your own risk.