Flashield - A Hybrid Key-value Cache that Controls Flash Write Amplification

Explore a 25-minute conference talk from USENIX NSDI '19 that introduces Flashield, a hybrid key-value cache designed to control flash write amplification in SSD storage. Learn how this innovative system uses DRAM as a filter to limit writes to SSD, employing lightweight machine learning for admission control. Discover the novel in-memory indexing technique that efficiently utilizes cache memory for variable-sized objects stored on flash. Understand how Flashield maintains a low write amplification of 0.5× compared to state-of-the-art systems, without compromising hit rate or throughput. Gain insights into the challenges of using SSDs for write-heavy use cases in cloud application databases and how Flashield addresses these issues.

Introduction
Keyvalue Caches
Latency
SSD Durability
Write Amplification
How it works
Example
Flashield demo
Clock algorithm
Flashield example
Updating the index
White gaps
Segment utilization
Collisions
Heat Rates
Summary
Questions