Ucache Read Cache

Overview

In a balanced storage system, data from different clients is aggregated to the backend. As a result, data block storage continuity is disordered, affecting read performance. The Ucache read cache system identifies the I/O patterns (sequential, reverse, interleaved, or hotspot) of user applications on a client and uses the prefetch policy to increase the data hit rate.

Technical Principles

The smart prefetch analysis engine and execution engine are deployed separately. The analysis engine uses multiple algorithms to identify sequential, reverse, interleaved, and hotspot streams, and prefetches target data to the read cache. Such data is directly hit in the cache, reducing read latency and drive read pressure.

Expected Results

The performance is doubled in various scenarios, including block storage services, hotspot, sequential, and interleaved read in a 4 KB cluster or single volume, workload proxy, and 4 KB read.