Author: N K

A distributed system provides benefits such as scalability and fault tolerance. However, maintaining consistency across the distributed system is non-trivial. Consistency is vital to achieving reliability, deterministic system state, and improved user experience.

A distributed system replicates the data across multiple servers to attain improved fault tolerance, scalability, and reliability. The consistency patterns (consistency models) are a set of techniques for data storage and data management in a distributed system. The consistency pattern determines the data propagation across the distributed system. Hence, the consistency pattern will impact the scalability and reliability of the distributed system.

The system design of the Presence Platform depends on the design of the Real-Time Platform. I highly recommend reading the related article to improve your system design skills. The original article was published on systemdesign.one website.

What Is the Real-Time Presence Platform?

The presence status is a key feature to make the real-time platform engaging and interactive for the users (clients). In layman’s terms, the presence status shows whether a particular client is currently online or offline. The presence status is popular on real-time messaging applications and social networking platforms such as LinkedIn, Facebook, and Slack [2]. The presence status represents the availability of the client for communication on a chat application or a social network.

The popular implementations of the ride-hailing service are the following:

• Uber
• Lyft
• Curb
• Grab

Requirements

• The rider can see all the available nearby drivers
• The driver can accept a trip requested by the rider
• The current location of the rider and driver should be continuously published on the trip confirmation

Data Storage