This article explains how ByteDance extended the Apache HDFS architecture with a multi‑datacenter design, introducing components such as DanceNN, NNProxy, and BookKeeper to achieve scalable storage, cross‑datacenter data placement, and rack‑level disaster recovery for petabyte‑scale workloads.
This article introduces the DPRD hierarchical data placement strategy, explains its roots in the CRUSH algorithm, highlights CRUSH's migration inefficiencies, and details how DPRD achieves near‑theoretical replica movement and balanced distribution during both expansion and shrinkage of a distributed storage system.
This article systematically explores the distributed characteristics of NoSQL databases, covering consistency trade‑offs, replication techniques, anti‑entropy protocols, data placement strategies, failure detection, and coordinator election, while illustrating each concept with diagrams and practical examples.
