Flushcommits

Flushcommits is a concept in software systems referring to the process of persisting in-memory commit entries to durable storage in a controlled, batched manner. It is used in contexts such as databases, log-structured storage engines, and event-sourced architectures to balance throughput with durability.

Function and purpose: The primary goal of flushcommits is to ensure that completed transactions or events are durably recorded so they can be recovered after a crash. By batching commits, systems can reduce the overhead of disk I/O while still providing strong durability guarantees. Flush policies may define how often a batch is written, how many commits trigger a flush, and what ordering is preserved.

How it works: Typically, a transaction or event is first recorded in an in-memory commit queue. When a flush is triggered—by time interval, batch size, or explicit request—the system writes the batch to a write-ahead log or commit log on persistent storage and synchronizes the file system to guarantee durability. Depending on the design, commit acknowledgments may be returned before or after the flush completes, affecting latency and durability guarantees.

Use cases: Flushcommits is common in high-throughput transactional systems, distributed databases with replication, and event-sourcing platforms where reliable replay of committed events is essential.

Considerations: Key trade-offs include durability versus latency, the reliability of the storage medium, and failure handling. Proper sequencing guarantees, idempotency, and error handling are important to avoid data inconsistency during partial flushes or recoveries.

See also: write-ahead log, commit log, batch processing, durability guarantees.