Realtime A-Z

A resource designed to help you discover Ably content on technologies and key realtime concepts.


Ably vs WebSockets: Choosing the right realtime technology for your app

This page compares Ably with WebSockets, the lower-level protocol that Ably is based on.

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Activity Feeds: Explanation, benefits and how to get started

Discover what activity feeds and streams are and how to use Ably APIs and SDKs to set one up.

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AMQP 1.0

Advanced Message Queuing Protocol (AMQP) is a protocol that can be used to retrieve messages from a queue. Discover how it works.

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APNs is a cloud service that enables third-party developers to push notifications to applications on Apple devices over a secure connection.

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AWS SNS is a simple, distributed, cloud-native messaging service. Discover how it works, its pros and cons, and more.

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AWS SQS is a distributed message queuing service for asynchronous messaging. Learn how it works, and its pros and cons.

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Event-driven architecture patterns and when to use them

Discover the two major patterns for event-driven architectures and the use cases for each, complete with examples.

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Event-driven architecture: Challenges and how to overcome them

Event-driven architecture (EDA) is a complex solution to a complex problem. Here, we cover a few of EDAs biggest challenges and how to manage with them.

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Event-driven architecture: Everything you need to know in 2024

Event-driven architecture, or EDA, is a software architecture that decouples event publishers and subscribers to enable realtime message delivery.

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FeathersJS Deep Dive

An examination of the FeathersJS framework and its realtime functionality — what it is, setup, limitations.

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Guide to Django Channels: What it is, pros and cons and use cases

Django Channels adds WebSocket support to the Django framework, making it possible to develop realtime functionality like chat and multiplayer collaboration.

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HTTP Long Polling - What it is and when to use it

This article is deep dive into the technique known as “long polling”: how it came to be, how it's implemented, and how we use it at Ably.

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Idempotency - Challenges and Solutions Over HTTP

An idempotent operation is one whose effect is the same whether it is performed once or multiple times. Learn more about idempotency, and how Ably provides it.

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MQTT vs. WebSocket - Key differences and when to use them together

Discover the different features, performance characteristics and use cases for MQTT and WebSocket, and how they can be used together.

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MQTT: The complete guide

A conceptual deep-dive into MQTT, how it works, and its uses now and in the future.

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Pub/Sub pattern architecture

Learn about the key components involved in any Pub/Sub system, understand the characteristics of Pub/Sub architecture, and explore its benefits.

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Scaling Firebase - Practical considerations and limitations

Firebase is used to keep frontend clients and your backend in sync - for example, chat apps, and multiplayer collaboration. But how well does it scale?

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Scaling SignalR: Available options and key challenges

Learn how to scale ASP.NET Core SignalR and Azure SignalR Service, and discover the challenges you’ll face along the way.

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Scaling Socket.IO - practical considerations

A review of Socket.IO’s advantages, limitations & performance. Learn about the challenges of using Socket.IO to deliver realtime apps at scale.

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Sendbird alternatives: 9 competitors to consider in 2024

Discover the best solutions you can use instead of Sendbird to build web-based and in-app chat experiences.

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Server-Sent Events: A WebSockets alternative ready for another look

This page is your introduction to Server-Sent Events (SSEs) - how they work, when to use them, and key considerations and challenges to be aware of.

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SignalR deep dive: Key concepts, use cases, and limitations

Learn about SignaR’s features, discover what kind of realtime experiences you can build with it, and read about its limitations and alternatives.

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Socket.IO: How it works, when to use it, and how to get started

Socket.IO's main use cases, how to get started, ideal use cases, scope for support, where it fits in the realtime landscape.

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SockJS is a JavaScript library that enables full-duplex communication. It works cross-browser and allows for low-latency communication. Find out how it works.

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The challenge of scaling WebSockets [with video]

Scaling WebSockets for a production system can be challenging in terms of load balancing, fallback strategy, and connection management. Here's how to tackle it.

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Webhooks – A Conceptual Deep Dive

With Webhooks you can set up integration rules based on published messages or presence events emitted on channels. Find out how they work, use cases, and more.

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WebRTC is a free, open-source project enabling p2p comms in browsers and mobile apps via APIs, including audio, video, and data transfers.

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WebSocket API and protocol explained: How they work, are used and more

We cover the WebSocket protocol and API, how WebSockets work, WebSocket use cases, pros and cons, WebSocket alternatives, WebSocket scalability, and more.

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WebSocket security: How to prevent 9 common vulnerabilities

Discover the most common WebSocket security vulnerabilities and how to prevent them through a combination of modern security approaches and testing tools.

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WebSockets vs HTTP: Which to choose for your project in 2024

Pros and cons of HTTP and WebSocket protocols, and when best to use them.

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WebSub – A deep dive

This article explores the history of WebSub, how it works, use cases (including big names who have adopted it), and the challenges of using WebSub.

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What is Event Streaming? A Deep Dive

An event streaming deep dive. Its elemental components, use cases, alternatives, and review of some open-source and commercial implementations.

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What is Pub/Sub? The Publish/Subscribe model explained

Learn everything you need to know about Pub/Sub, a design pattern that’s used to implement event-driven architectures and realtime messaging systems.

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XMPP is an XML-based messaging protocol for realtime data transmission between distributed systems. Learn how it works, and its pros and cons.

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Learn about ZeroMQ, an asynchronous message queue library for building messaging middleware brokers or protocols for distributed or concurrent applications.

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