1. 4.6 Replication Architectureshistorical

    The three common replication topologies: single-leader, multi-leader, and leaderless replication, and the trade-offs each introduces.

  2. 5. Distributed-System Partitioninghistorical

    How partitioning splits a dataset across nodes, why it scales storage and read/write throughput, and how partitioning differs from replication.

  3. 5.1 Partitioning: Splitting Datahistorical

    How to choose a partition key and compare explicit, random, range, modulo-hash, consistent-hash, virtual-node, and hash-slot partitioning.

  4. 5.2 Partitioning: Request Processinghistorical

    How shard keys determine targeted routing, why missing shard keys cause scatter/gather, and the difference between local and global secondary indexes.

  5. 5.3 Partition Routing Componentshistorical

    Three ways to locate a partition owner: client-side routing, a dedicated proxy, or server-side forwarding/redirects.

  6. 5.4 Partition Assignment and Rebalancinghistorical

    How logical partitions are assigned to machines, static versus dynamic placement, and what changes when a cluster rebalances.