KELI: a key-value-with-links in-memory store for realtime applications.

The emergence of advanced network technologies and decreasing DRAM costs have provided great opportunities for data centers to deploy high performance key-value in-memory stores for real-time applications. Although key-value model helps in-memory stores to simplify their query processing and data management mechanisms, its simplicity have applications to generate multiple item lookups to perform simple requests such as constructing HTML files. Such lookups are often executed sequentially and seriously affect the overall performance. In this paper, we introduce KELI, a novel in-memory key-value store that employs Key-value-with-Links, a simple but quite efficient data model, to solve this issue. On the top of the key-value model, KELI establishes links between items so instead of invoking expensive item lookups, it could simply follow those links to retrieve needed data. KELI also uses RDMA Read to implement link chasing to minimize searching overhead. Some experiments have been conducted to examine the performance of KELI. Their results indicate that KELI runs three times faster than Redis for data lookups. Furthermore, KELI runs seven times faster than Redis when handling real workloads generated by a practical application.