July 2018 Summaries

The article discusses the development of a horizontally scalable rate limiter for Ably's realtime messaging platform, addressing challenges such as enforcing instantaneous rate limits and maintaining service quality for other customers during sudden traffic surges. The solution involved introducing an account-wide, global, near-instantaneous message rate limit with specific design constraints including guaranteed message delivery, no blind fanout limit, scalability, throughput stability, predictability, and fast reaction time. The final implementation used a probabilistic suppression factor based on the degree by which the account was beyond its limit, combined with a moving average of the rate measured over 24 seconds. Further improvements included tracking the total number of messages that would have been generated had they succeeded, allowing for more accurate calculation of the suppression rate needed to ensure aggregate message rate exactly at the limit and avoid oscillation.

The 'Distributed Deep Dive' video interview series is a new initiative by Ably Realtime aimed at sharing knowledge and best practices about distributed systems, an area considered critical for platform-as-a-service (PaaS) offerings. The series features interviews with experienced engineers who share their experiences, challenges, and lessons learned while working with distributed systems. Interviews are hosted on the company's YouTube channel and transcripts are also available. Viewers can participate by commenting on videos or blog posts, or reaching out to Ably Realtime directly for more private discussions. The first episode features an interview with Paul Nordstrom, an expert in system architecture with experience at companies like Google, Amazon, and OfferUp.

The article discusses the Internet of Things (IoT) and its application in healthcare through the Internet of Medical Things (IoMT). IoMT allows medical devices and applications to gather data and communicate with healthcare IT systems over a wireless network. By 2020, it is expected that 200 billion devices will be connected, with 38% of the total value coming from devices in health care. The article explores various use cases of IoMT such as real-time patient monitoring, wearables tech devices, and urgent care push notifications. It also highlights the importance of security in IoMT due to the sensitive data being shared across smart devices and the need for legislation to prevent data leaks. Virtual Reality (VR) and Augmented Reality (AR) are seen as potential tools to further expand the usage of IoT in health care, improving patient experience and reducing costs.

Ably has developed a new wiki system for internal use due to issues with GitHub Wiki functionality. They chose Sinatra as their web application framework and Jekyll to convert markdown files into static sites. Simple-Jekyll-Search was used for page searching, Auth0 for authentication, and Heroku for hosting. The final product is a private, searchable wiki hosted on Ably's own site.