Creating a Big Data application with data visualization using React, Node.js, and MongoDB involves multiple components and a considerable amount of code. Below, I'll provide simplified examples for each component to give you a starting point. Please note that these are simplified and won't cover all aspects of a production-ready application.

Sample Node.js Backend (server.js):

const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');

const app = express();
const port = process.env.PORT || 3001;

// Connect to MongoDB
mongoose.connect('mongodb://localhost/bigdata_db', {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});

// Define a schema and model for MongoDB
const dataSchema = new mongoose.Schema({
  name: String,
  value: Number,
});

const DataModel = mongoose.model('Data', dataSchema);

app.use(bodyParser.json());

// Create an API endpoint to fetch data
app.get('/api/data', async (req, res) => {
  try {
    const data = await DataModel.find();
    res.json(data);
  } catch (error) {
    console.error(error);
    res.status(500).json({ error: 'Internal Server Error' });
  }
});

app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

Sample React Frontend Component (DataVisualization.js):

import React, { useState, useEffect } from 'react';
import axios from 'axios';

const DataVisualization = () => {
  const [data, setData] = useState([]);

  useEffect(() => {
    // Fetch data from the backend API
    axios.get('/api/data')
      .then((response) => {
        setData(response.data);
      })
      .catch((error) => {
        console.error(error);
      });
  }, []);

  // Example data visualization using a simple table
  const renderTable = () => {
    return (
      <table>
        <thead>
          <tr>
            <th>Name</th>
            <th>Value</th>
          </tr>
        </thead>
        <tbody>
          {data.map((item) => (
            <tr key={item._id}>
              <td>{item.name}</td>
              <td>{item.value}</td>
            </tr>
          ))}
        </tbody>
      </table>
    );
  };

  return (
    <div>
      <h2>Data Visualization</h2>
      {data.length > 0 ? renderTable() : <p>Loading data...</p>}
    </div>
  );
};

export default DataVisualization;

Sample React App (App.js):

import React from 'react';
import DataVisualization from './DataVisualization';

function App() {
  return (
    <div className="App">
      <h1>Big Data Visualization App</h1>
      <DataVisualization />
    </div>
  );
}

export default App;

In this simplified example:

• The Node.js backend sets up an Express server and connects to a local MongoDB database.

• It defines a data schema for MongoDB and provides an API endpoint to fetch data.

• The React frontend component (DataVisualization.js) fetches data from the backend and displays it in a simple table.

• The React app (App.js) includes the DataVisualization component.

To run this example, ensure you have Node.js, MongoDB, and a React development environment set up. Also, make sure MongoDB is running locally with a database named bigdata_db and a collection named data. You can customize the MongoDB connection URL in the backend code to match your configuration.

This example demonstrates a basic setup for data retrieval and visualization. For real-world scenarios, you would likely use more sophisticated data visualization libraries and handle larger datasets with pagination, filtering, and other features.