hesela.devBP-Wrapper
BP-Wrapper is a buffer-management framework that batches replacement-policy updates and prefetches their metadata to reduce lock contention.
The ICDE 2009 design records hits in per-thread FIFO queues. At the batch threshold it tries the policy lock without blocking; a full queue requires acquiring the lock. A miss commits the thread's pending hits before its miss operation. Per-thread order is preserved, not a single immediate global recency order. [1]
Prefetching brings replacement metadata into the processor cache before the critical section; database-page read-ahead is a separate operation. Evaluation used modified PostgreSQL 8.2.3 on two multiprocessor systems, not current PostgreSQL or SSD firmware. [1]
Caffeine cites this work but has a different buffering contract. Its read buffer may reject events under contention or when full. Batching therefore does not, by itself, specify whether observations are retained. [2]
Relations
Limitations
- Delaying policy bookkeeping can change victim choices without changing the correctness of the buffered data. [1]
Citations
- Ding, Jiang and Zhang. BP-Wrapper. ICDE 2009, pp. 369-380, sections III-IV; DOI 10.1109/ICDE.2009.96.
- Caffeine v3.2.3, BoundedLocalCache.java: concurrency contract, afterRead, drainReadBuffer and onAccess. Commit 5227a98b51e02b4d4fbfc2b0e33c362a138f51b1.
Sources & caveats
- Primary-source review of the original paper and pinned library implementation; no new throughput measurement or implementation replication.