Primary-Replica vs Peer-to-Peer Replication (Trade-offs) PDF

212 Primary-Replica vs Peer-to-Peer Replication * * (Trade-offs) Primary-Replica and Peer-to-Peer Replication are two distinct approaches to data replication in * ** *** distributed systems, each with its own us...

212 Primary-Replica vs Peer-to-Peer Replication * * (Trade-offs) Primary-Replica and Peer-to-Peer Replication are two distinct approaches to data replication in * ** *** distributed systems, each with its own use cases, benefits, and challenges. * * * * * * Primary-Replica Replication ** Definition: ** In Primary-Replica (also known as Master-Slave) replication, one server (the primary/master) ** ** *** ** handles all the write operations, and the changes are then replicated to one or more other servers * * (replicas/slaves). * ** Characteristics: ** *** Unidirectional: Data flows from the primary to the replicas. *** * * * * ** Read and Write Split: ** The primary handles writes, *** * * ***  ❗ * while replicas handle read queries, thereby distributing the load. * *** * * * * *** * * ** Example: ** A popular example is a web application with a database backend. *** *** The primary database handles all write operations (like new user signups or content postings), * * *** *** *** *** * while multiple replica databases handle read operations (like users browsing the site). * * * * * ** Pros: ** ** Simplicity: Easier to maintain and ensure consistency. ** * * ** Read Scalability: Can scale read operations by adding more replicas. ** * * ** Cons: ** ** Single Point of Failure: The primary is a critical point; if it fails, the system cannot process ** * * write operations. ** Replication Lag: Changes made to the primary might take time to propagate to the replicas. ** * * * * Peer-to-Peer Replication ** Definition: ** In Peer-to-Peer replication, each node (peer) in the network can act both as a client and a ***  ❗ server. *** * Peers are equally privileged and can initiate or complete replication processes. ** ** * ** Characteristics: ** *** Multi-Directional: Any node can replicate its data to any other node, and vice versa. * ** * * * * * * * * ** Autonomy: Each peer maintains its copy of the data and can independently respond to read and ** * * write requests. ** Example: ** A file-sharing application like BitTorrent uses peer-to-peer replication. Each user (peer) in the ** ** *** *** * * network can download files (data) from others and simultaneously upload files to others. ** Pros: ** ** Decentralization: Eliminates single points of failure and bottlenecks. ** * * ~~ ~~ ~~ ~~ *** Load Distribution: Spreads the load evenly across the network. * ** ** Cons: ** ** Complexity: More complex to manage and ensure data consistency across all nodes. ** ** Conflict Resolution: Handling data conflicts can be challenging due to simultaneous ** *** *** * * updates from multiple peers. * * Key Differences ** Control and Flow: ** In Primary-Replica replication, the primary has control over write operations, with a clear flow ** ** *** ** * of data from the primary to replicas. In Peer-to-Peer, every node can perform read and write operations, and data flow is multi- ** ** *** ** * * directional. * ** Architecture: ** ** Primary-Replica follows a more centralized architecture, ** *** *** * whereas Peer-to-Peer is decentralized. * ** ** *** *** ** Use Cases: ** ** Primary-Replica is ideal for applications where read-heavy operations need to be scaled. ** *** ** * ** Peer-to-Peer is suited for distributed networks where decentralization and load distribution are ** * * * * * critical, such as in file sharing or blockchain technologies. * *** *** *** *** Conclusion The choice between Primary-Replica and Peer-to-Peer replication depends on the specific * requirements of the application, such as the need for scalability, fault tolerance, and the desired level * * * * * * of decentralization. * ** Primary-Replica offers simplicity and read scalability, making it suitable for traditional ** * * * * * database applications. * * In contrast, Peer-to-Peer provides robustness against failures and load distribution, ideal for * ** ** * * * * * decentralized networks. *