In-Network Aggregation as a Generic Service for Distributed Applications

The performance of distributed applications has long been hindered by network communication, which has emerged as a significant bottleneck. At the core of this issue, the many-to-one incast transfer stands out as one of the primary culprits. Existing works typically decompose the transmission into multiple concurrent sub-processes and utilize servers to aggregate relevant traffic, thus avoiding the incast transfer. However, limited by their theoretical bounds, these methods can only obtain limited performance improvement. In this paper, we discover that leveraging network devices for aggregating incast traffic proves highly effective in surpassing such limitations, while the advent of programmable switches further makes this envision practical. Based on this, we propose GISA as a solution for providing network acceleration across diverse distributed applications. GISA offers generic and uniform interfaces to various applications along with a switch resource sharing mechanism and policy for concurrent tasks. It also ensures correct and reliable transport while minimizing overhead through a low-overhead routing mechanism. Our FPGA-based prototype demonstrates that GISA can achieve line-rate processing when performing data aggregation with minor traffic overhead. Additionally, it supports a wide range of concurrent applications with little development effort.