A Cost Analysis of Replication vs S3 Express One Zone in Transactional Data Systems
Is it economical to build fault-tolerant transactional data systems directly on S3 Express One Zone, instead of using replication? Read on for an analysis.
Cloud object storage is becoming the universal storage layer for a wealth of cloud data systems. Some systems use object stores as the only storage layer, accepting the higher latency of object storage, and these tend to be analytics systems that can accept multi-second latencies. Transactional systems want single-digit millisecond latencies or latencies in the low tens of milliseconds and therefore don’t write to object stores directly. Instead, they land data on a fast replicated write-ahead-log (WAL) and offload data to an object store for read-optimized long-term, economical storage. Neon is a good example of this architecture. Writes hit a low-latency replicated write-ahead-log based on Multi-Paxos and data is eventually written to object storage.
Both Kafka and Confluent’s Kora also use this architecture, which in streaming tends to be called tiered storage. Essentially, the Kafka/Kora brokers are a replicated write-cache and serving layer, and data gets compacted into larger objects and offloaded to more economical cloud storage asynchronously.
