HDFS architecture, distributed file system, big data storage, cluster nodes, master node, slave nodes, namenode, datanodes, rack awareness, network topology, data replication, block reports, heartbeat messages, metadata management, file system namespace, Unix-like directory hierarchy, permission-based access control, data locality, read and write operations, Java-based implementation, scalable and fault-tolerant design, high availability, load balancing, cloud computing background, minimalist composition, subtle gradient lighting.