论文标题
Histore：在基于RDMA的键值商店中重新思考混合指数
HiStore: Rethinking Hybrid Index in RDMA-based Key-Value Store
论文作者
论文摘要
RDMA（远程直接内存访问）在构建键值商店中被广泛利用，以实现超低延迟。在基于RDMA的键值商店中，索引时间需要大量的总体操作延迟时间（RDMA启用快速数据访问）。但是，在现有的基于RDMA的键值商店中使用的单个索引结构，无论是基于哈希的索引还是排序索引，都无法有效地支持范围查询，同时实现了单点操作的高性能。在本文中，我们重新考虑了基于RDMA的键值商店中混合指数的采用，以结合哈希表的好处和排序索引。我们建议使用Hash Taber进行单点查找，并利用Skiplist进行范围查询的Histore，这是一种基于RDMA的键值存储。为了在轻巧有效的方法中保持强大的一致性，Histore引入了索引组，其中kiplist对应于哈希表，并且异步将更新应用于组中的skiplist。在先前使用RDMA进行键值服务的工作的指导下，Histore专门选择了不同的RDMA原语，以优化读写性能。此外，Histore可以容忍具有索引复制的索引结构的服务器的故障，以获得高可用性。我们的评估结果表明，Histore通过混合指数提高了GET和SCAN操作（最高2.03倍）的性能。
RDMA (Remote Direct Memory Access) is widely exploited in building key-value stores to achieve ultra low latency. In RDMA-based key-value stores, the indexing time takes a large fraction (up to 74%) of the overall operation latency as RDMA enables fast data accesses. However, the single index structure used in existing RDMA-based key-value stores, either hash-based or sorted index, fails to support range queries efficiently while achieving high performance for single-point operations. In this paper, we reconsider the adoption of hybrid index in the key-value stores based on RDMA, to combine the benefits of hash table and sorted index. We propose HiStore, an RDMA-based key-value store using hash table for single-point lookups and leveraging skiplist for range queries. To maintain strong consistency in a lightweight and efficient approach, HiStore introduces index groups where a skiplist corresponds to a hash table, and asynchronously applies updates to the skiplist within a group. Guided by previous work on using RDMA for key-value services, HiStore dedicatedly chooses different RDMA primitives to optimize the read and write performance. Furthermore, HiStore tolerates the failures of servers that maintain index structures with index replication for high availability. Our evaluation results demonstrate that HiStore improves the performance of both GET and SCAN operations (by up to 2.03x) with hybrid index.
