一句话:提出MaxEmbed,用带复制的嵌入存储组合挖掘与在线查询优化,缓解SSD读放大并提升嵌入模型服务吞吐。
DLRM依赖超大嵌入表表示稀疏特征,面临内存容量与成本问题;SSD容量大且成本低,但嵌入项大小与SSD读粒度不匹配会导致读放大。已有系统用超图划分把共现嵌入放到同一SSD页,却将嵌入划分为互不相交簇,限制了嵌入组合。MaxEmbed利用SSD大容量,通过复制挖掘嵌入存储组合间关系,提升有效带宽;并加入在线服务模块处理嵌入查询请求,用两项优化降低复制开销。评估显示,在不同设置下,MaxEmbed将SSD嵌入服务吞吐最高提升18.7%。
Deep learning recommendation models (DLRMs) have gained widespread application across search, advertising, and e-commerce. Still, DLRMs present notable challenges as they depend heavily on large embedding tables to represent sparse features in recommendation systems. This raises concerns about both memory capacity and cost. Solid-state drives (SSDs) offer a cost-effective solution with a significantly larger capacity, but they introduce read amplification issues because of the mismatch between embedding size and SSD read granularity. Prior SSD embedding storage systems aim to tackle these challenges by employing hypergraph partitioning to co-locate co-appearing embeddings onto the same SSD page, alleviating read amplification. However, this approach has a drawback as it divides embeddings into completely disjoint clusters, limiting potential combinations between embeddings. In response to this limitation, we introduce MaxEmbed. Capitalizing on the extensive storage capacity of SSDs, Max-Embed effectively mines relationships between storage combinations of embeddings with replication, thereby enhancing the effective bandwidth of SSDs. Additionally, MaxEmbed incorporates a corresponding online service module for embedding query request handling, leveraging two key optimizations to reduce the overhead brought by replication. Our evaluations demonstrate that MaxEmbed boosts SSD embedding serving throughput by up to 18.7% under various settings.