Streaming Backpressure Demo

Watch how the backpressure manager handles high-speed data streams. Adjust the data rate and buffer size to see different overflow strategies in action.

Streaming Backpressure Demo

Watch how the buffer handles high-speed data with different overflow strategies

Overflow StrategyDrop OldestDrop NewestSample (1 in N)

Data Rate1,000 pts/s

Buffer Size500

0%

Buffer Fill

0

Incoming/s

0

Processed/s

0

Dropped

STOPPED

Stream State

Buffer Health:Healthy

How It Works

When data arrives faster than it can be processed, the buffer fills up. The backpressure manager uses different strategies to handle overflow:

Strategy	Behavior
Drop Oldest	Removes oldest points to make room for new ones
Drop Newest	Ignores new points when buffer is full
Sample	Keeps every Nth point (downsampling)
Pause	Stops accepting data until buffer drains

Health Metrics

• Buffer Fill - Current buffer utilization (0-100%)
• Incoming Rate - Points arriving per second
• Outgoing Rate - Points consumed per second
• Dropped - Total points lost due to overflow
• Health Score - Overall buffer health (0-100)

Usage

import { 
  BackpressureManager,
  createBackpressureManager,
  createRealtimeBackpressure,
} from 'scichart-engine';

// Create a backpressure manager
const bp = createBackpressureManager(10000, 'drop-oldest');

// Or with full options
const bp = new BackpressureManager({
  maxBuffer: 10000,
  strategy: 'drop-oldest',
  warningThreshold: 0.7,    // 70% = warning
  criticalThreshold: 0.9,   // 90% = critical
  onOverflow: (dropped) => {
    console.log(`Dropped ${dropped} points`);
  },
});

// Push incoming data
websocket.onmessage = (data) => {
  bp.push('sensor1', data.points);
};

// Consume for chart updates
setInterval(() => {
  const points = bp.consume('sensor1', 100);
  chart.appendData('series1', points);
}, 16);

// Check health
const health = bp.getHealth();
if (health.status === 'critical') {
  console.warn('Buffer under heavy load!');
}

Strategies Explained

Drop Oldest (Recommended for Real-time)

const bp = createBackpressureManager(5000, 'drop-oldest');
// Best for live monitoring where recent data matters most

Pause (For Lossless Data)

const bp = createLosslessBackpressure(100000);
// Pauses stream when full - no data loss
// Requires handling the paused state

Sample (For High-frequency Sensors)

const bp = new BackpressureManager({
  maxBuffer: 5000,
  strategy: 'sample',
  sampleRate: 4,  // Keep 1 in every 4 points
});

Circular Buffer

For custom implementations, use the CircularBuffer directly:

import { CircularBuffer } from 'scichart-engine';

const buffer = new CircularBuffer(1000);

buffer.push(point);           // Add (returns false if full)
buffer.pushOverwrite(point);  // Add, overwrite oldest if full
buffer.shift();               // Remove oldest
buffer.shiftMany(100);        // Remove N oldest
buffer.fillLevel();           // 0.0 - 1.0
buffer.isFull();
buffer.isEmpty();

See Streaming Guide for more on real-time data handling.