Technical deep-dives into systems architecture and engineering explorations.
The Fallacy of the Ring: Why Scale Requires Tablet-Based Placement
In distributed systems, we often confuse Partitioning (how we logically slice data) with Placement (the physical location of that data on hardware). This distinction remains academic while your dataset fits on a single NVMe drive. But at the limit—where nodes are added and removed daily—this distinction determines if your system scales linearly or collapses under its own weight. The Problem with the Hash Ring First-generation distributed databases used Consistent Hashing to coordinate data without a central authority. However, the “Ring” model has a major weakness: Placement is tied directly to the Ring Topology. When you add or remove a server form a hash ring, you change the mathematical boundaries of the entire keyspace. This forces a “Shuffle”—a massive, automatic movement of data where where the cluster must physically realign itself to satisfy the new math. ...