How Many Users and Concurrent Connections Can PubNub Support?

PubNub, a leading Data Stream Network (DSN), is designed to handle high concurrency and user scalability, offering a robust infrastructure for millions of connections across the globe.

PubNub Scalability and Stability

PubNub’s architecture is built to support:

• Millions of concurrent users: PubNub supports millions of users across devices and channels, enabling large-scale real-time deployments effortlessly.
• Billions of messages daily: PubNub’s global network processes over 16 trillion transactions per month.
• Security: PubNub ensures data privacy and integrity with end-to-end encryption, protecting messages during transmission

Concurrent Connections

A “connection” in PubNub refers to an active client (e.g., a mobile app, browser, or IoT device) subscribing to one or more channels. PubNub’s underlying system supports:

• Up to 100 million concurrent connections globally: This is achieved by leveraging its distributed edge infrastructure across 15+ data centers worldwide.
• Horizontal scalability: PubNub’s infrastructure automatically scales horizontally to handle spikes in traffic, ensuring consistent performance even during surges or anomalies. 

Message Throughput

PubNub guarantees low-latency delivery of messages, handling billions of messages daily, and this throughput is evenly distributed across its architecture to avoid bottlenecks.

• Each channel can process tens of thousands of messages per second.
• With smart fan-out mechanisms, PubNub ensures messages are efficiently delivered to millions of subscribers without degrading performance.

Key Factors That Enable Large Scale

1. Global Edge Network

PubNub operates a global edge network with data centers distributed across major regions (North America, Europe, Asia-Pacific, and more). By routing data through the nearest edge node, the platform minimizes latency and optimizes delivery speed for users worldwide.

2. Efficient Protocols

PubNub uses efficient protocols such as WebSocket and HTTP/2, enabling lightweight, persistent connections that reduce overhead and optimize bandwidth usage. These protocols are crucial for supporting high concurrency without consuming excessive resources.

3. Channel Multiplexing

Developers can create unlimited channels in PubNub. Channels allow segmentation of messages and connections, providing fine-grained control over how data is delivered. Each client can subscribe to up to 50-100 channels concurrently, depending on the SDK used.

4. Elastic Infrastructure

PubNub’s backend dynamically scales its infrastructure in response to traffic demands. This elasticity ensures that both steady-state and burst workloads are handled seamlessly without requiring intervention from developers.

5. Reliability and Redundancy

PubNub provides 99.999% uptime SLA through redundancy and failover mechanisms. Data is replicated across multiple nodes to prevent downtime or message loss, even in network failures.

Real-World Examples of Scale

1. Multiplayer Gaming:

• A popular multiplayer game uses PubNub to handle over 5 million concurrent players with real-time state synchronization.
• Players exchange positional data and events delivered globally with latency under 40ms. Check live network latency status >>

1. IoT Platforms:

• An industrial IoT platform connects 500,000+ devices to monitor and control operations in real-time.
• Each device publishes telemetry data every few seconds, resulting in millions of messages processed hourly.

1. Live Events:

• A live-streaming platform delivers interactive experiences to 10 million viewers who engage via chat and polls.
• PubNub ensures seamless message delivery during peak moments with no lag or dropouts.

Considerations for Scaling with PubNub

While PubNub handles the heavy lifting, developers should consider the following when building at scale:

1. Message Limits: Messages are limited to 32 KB. We’ll split larger payloads or use external storage.
2. Rate Limits: Although PubNub provides generous throughput limits, plan for your expected message rate and consult with PubNub’s support team for high-volume scenarios.
3. SDK Optimizations: Optimize client-side SDK usage to reduce unnecessary overhead. For instance, limit excessive channel subscriptions or use batching for publish operations.

Summary

PubNub is engineered for massive scale, supporting millions of users and billions of messages without compromising performance or reliability. Whether you’re building an eCommerce platform, media streaming service, global chat app, real-time IoT solution, or a multiplayer gaming experience, PubNub’s infrastructure ensures seamless scalability as your user base expands.

If your use case involves unique scaling needs, PubNub offers dedicated technical support to help design and implement solutions that fit your requirements. The platform’s scalability, reliability, and developer-friendly features make it a trusted choice for real-time applications of any size.

More details? Visit PubNub’s official documentation or contact us for guidance tailored to your project.