This paper presents Chardonnay, a scale-out, generalpurpose, multi-versioned, on-disk transactional keyvalue store optimized for single datacenter deployments with fast 2PC. Chardonnay takes advantage of fast RPCs to support strictly serializable snapshot reads without relying on specialized clocks or assumptions about maximum clock skew. Chardonnay achieves high performance for high contention workloads by automatically and transparently loading and pinning data from slow storage to main memory prior to acquiring any locks, and avoids deadlocks by ordering its lock requests. We believe that the design principles of Chardonnay can also be applied in other settings, such as multi-core singlenode systems for high contention workloads.

Based on a thorough theoretical and experimental analysis of tree indexes built on DM, this paper points out the performance bottleneck of B+ trees on DM due to severe read and write amplifications and then presents SMART, the first radixtree-based index on DM. SMART addresses the challenges of applying ART on DM, including a hybrid concurrency control scheme to reduce lock overhead and avoid cache thrashing, a read-delegation and write-combining technique to reduce redundant I/Os, and a tailed cache validation mechanism. Our evaluation results show that SMART outperforms the stateof-the-art B+ tree on DM by up to 6.1× under write-intensive workloads and 2.8× under read-only workloads.

We present Atlas, a hybrid dataplane that enables efficient far memory for bulk data and scattered objects simultaneously. Atlas outperforms both the state-of-the-art object-based and paging-based far memory systems.