ReCA-FTL: Resource Contention Aware Flash Translation Layer

This paper proposes a new Flash Translation Layer (FTL) scheme that improves the performance of SSDs by minimizing resource contention. This is achieved by holistically managing all the FTL issues such as page allocation, garbage collection, wear leveling, and scheduling to maintain load balancing. The proposed ReCA-FTL consists of Resource Balancing Allocation, Erasure Counts Balancing Garbage Collection, Hot/Cold-Pool Balancing Wear Leveling, and Resource Contention Cost based Scheduling. The RBA, ECB GC, and H/C-PB WL schemes are designed to balance the number of free pages, erasure counts, recent erasure counts, and the hot/cold pool membership. The RCCS scheme reschedules jumbled incoming requests to utilize advanced flash-chip commands. This alleviates resource contention allowing SSDs to utilize all the resources more effectively. Our detailed simulation study shows that the proposed FTL scheme provides on average of 1.75 and maximum of 2.04 times higher throughput than a selected baseline for a variety of workloads.