June 2023 Summaries

Chat protocols play a crucial role in driving product adoption, user engagement, and retention. There are various chat protocols to consider when implementing chat in an application, each addressing different aspects of the problem with varying degrees of thoroughness. Some popular protocols include WebSocket, WebRTC, MQTT, XMPP, AMPQ, Matrix, Server Sent Events, and IRC. When choosing a protocol, factors such as how clients connect, data types supported, reliability, latency, scalability, and security should be considered.

Ably has introduced Subscription Filters, a new feature that allows subscribers to create custom realtime data feeds by selectively subscribing to receive only part of the data from a channel. This feature benefits publishers by enabling them to create personalized data streams for large numbers of individual clients without worrying about scalability, maintenance, and reliability issues. Subscription Filters can be used in various applications such as chat rooms, social experiences, and data broadcasting. The code demonstrates how to add attributes to messages that can be used for filtering and subscribing to a channel with a filter expression. A demo showcases the feature's functionality in a stock inventory dashboard scenario.

Data push from server to client has been an ongoing challenge since the advent of the web. Early developers had to rely on ingenuity and novel solutions like polling, which compromised performance. As demand for real-time features increased, dedicated methods for sending data from the server emerged. There are four main options: WebSockets, XHR streaming (HTTP streaming), Server-Sent Events, and Server-Sent Events with Ably. The best method depends on factors such as compatibility, efficiency, ease of implementation, and scalability. Data push is a pattern where the server chooses to push data to the client(s) immediately without waiting for them to ask for it. It minimizes latency compared to data pull but does not allow two-way communication over the same channel. When choosing a data push approach, consider factors such as network environment, dependency chain, device support, legacy browsers, developer resources, and bidirectional requirements. The importance of reliable and low-latency updates cannot be overstated, especially when serving large numbers of users or operating in unreliable mobile networks. WebSockets, XHR streaming, Server-Sent Events, and Server-Sent Events with Ably each have their own strengths and limitations. By examining these methods and evaluating their advantages and disadvantages, developers can make an informed decision about which method is best suited to their specific needs.

Elasticity is a crucial aspect of real-time update systems as it enables the software infrastructure to adapt and scale according to fluctuations in usage. Real-time updates pose unique challenges for elasticity due to their resource-intensive nature and inevitable user fluctuations. The importance of achieving and maintaining elasticity is heightened by the fact that products with real-time updates typically offer a "live" experience, which can be broken if users cannot access updates promptly. The impact of scalability varies between companies providing real-time updates and those offering traditional services. For example, Facebook experienced a significant outage in 2021 but managed to recover as most users returned once the issue was resolved. However, for real-time update systems, even minor delays can lead to user dissatisfaction and churn. To efficiently manage an influx of users, companies can adopt either manual or automated strategies. Regardless of the chosen approach, factors such as scalability, reliability, security, and cost must be considered when building a real-time update infrastructure. Ably offers a data broadcast solution that ensures high levels of scalability and elasticity while maintaining data integrity. This enables companies to meet stringent real-time requirements and deliver seamless user experiences.

Live chat is a common realtime web experience that has become essential for businesses to provide faster customer support and improve user engagement. Realtime messaging systems are critical in delivering live chat experiences, as they ensure instant or near-instant message receipt and delivery. The challenges of scaling realtime messaging for chat use cases include ensuring message delivery across disconnections, achieving consistently low latencies, dealing with volatile demand, architecting the system for scale, and making it fault tolerant. To overcome these challenges, best practices such as preserving data integrity, using a low-latency protocol like WebSocket, choosing horizontal over vertical scaling, and utilizing an architecture pattern designed for scale like pub/sub are recommended.

The text discusses the importance of data integrity in real-time update systems. It explains that maintaining data integrity is crucial for ensuring an effective user experience, especially in scenarios where real-time updates are essential. Examples include financial trading platforms, sports apps, e-commerce websites, and ride-sharing applications. The article also highlights the challenges involved in scaling up real-time update systems while guaranteeing data integrity. It suggests that a well-designed system should ensure message order, delivery precision, and consistency even during network disruptions.

Chat applications have become an integral part of communication, connecting distributed workers, providing customer service, and bringing together online communities. The architecture of a chat app plays a crucial role in ensuring its reliability and scalability. Key considerations for chat app architecture include the ability to scale, fault tolerance, latency and global reach, message synchronization and queuing, transport mode, and implementing push notifications. The structure of chat architecture typically follows a client-service pattern with seven core components: application server, load balancer, streaming event manager, user authentication and user manager, presence service, media store, and database. There are three main options for delivering realtime chat applications: building everything in-house, integrating proven third-party tools, or using a white-label chat platform. Ably offers a global infrastructure with pub-sub architecture, rich integrations, and tutorials to build scalable chat applications.

A survey of over 500 engineering leaders by Ably revealed insights into the challenges and strategies for delivering realtime experiences across chat, collaborative tools, and interactive dashboards. The blog series provides detailed information on building realtime experiences in-house, including capabilities, costs, risks, and ways to reduce costs and deliver features faster. Ably is a realtime experience infrastructure provider that offers APIs and SDKs for developers to power various realtime applications at scale without worrying about managing messy infrastructure.

Low latency is crucial for delivering successful realtime updates, with latencies needing to be in the low hundreds of milliseconds for users to perceive updates as "live" or instantaneous. Two major reasons why low latency is important for realtime updates at scale are the brand promise of realtime and user expectations of scalability. Companies must ensure regional and global coverage, efficient message routing, manageable message payloads, and optimized encoding processes to guarantee low latency delivery at scale. Building a system from scratch can be costly and challenging, so many companies opt for services like Ably that provide APIs and SDKs for broadcasting realtime data with predictable low latency.

Ably has joined the Datadog Partner Network as a Technology Partner and launched an out-of-the-box integration, allowing users to visualize their Ably applications throughout their full lifecycle from development to test to production. The integration enables SRE and Operations teams to receive notifications on realtime metrics such as channel and message usage, peak connections, failed message requests, and more. Users can set up immediate Datadog alerts when an Ably app is not running as expected or approaches usage limits, observe Ably apps in correlation with other parts of the system from a single place, and forecast costs based on usage patterns via customizable out-of-the-box dashboards. The integration is available to Committed Use customers with an enterprise-grade package, and users need to be both Datadog and Ably customers to install it.