Toward smarter redundancy in Hadoop: a systematic review of replication and erasure coding approaches
摘要
The explosive growth of data in modern organizations has led to a greater reliance on distributed storage systems such as Hadoop Distributed File System (HDFS). To ensure reliability, HDFS traditionally keeps multiple replicas of each data block supported by a static placement strategy that distributes replicas across racks to balance availability and bandwidth usage. While effective for fault tolerance, this redundancy comes at a high storage and maintenance cost. However, existing surveys either treat Hadoop/HDFS redundancy as one component within broader cloud replication taxonomies, or focus on a limited subset of HDFS mechanisms. As a result, a systematic synthesis that jointly covers replication factor control, replica placement, and erasure coding in Hadoop/HDFS remains limited. This paper presents a systematic review of recent strategies aimed at making data redundancy in Hadoop smarter and more efficient. The review adopts a new taxonomy into three categories namely Erasure coding methods, Reactive replication strategies, and Predictive replication strategies. The selected papers are analyzed according to several criteria. Overall, the survey reveals a clear trend: Hadoop’s redundancy management is evolving beyond fixed triple replication and static placement toward more adaptive schemes that consider data popularity, workload dynamics, and cost-performance trade-offs. Finally, we discuss open challenges and outline how addressing these gaps can lead to more resilient and efficient big data storage in the future.