Coflow scheduling can effectively improve the application performance and has been studied a lot in cooperative environments (e.g., private datacenter networks), where fairness is not the primary concern. In non-cooperative environments (e.g., multi-tenant datacenter networks), coflow scheduling should be strategy-proof; otherwise, some tenants could unfairly acquire more resources by cheating the scheduler. As minimizing coflow completion time (CCT) must prioritize coflows based on some specific rules (e.g., shortest-coflow-first, smallest-effective-bottleneck-first), tenants can raise the priority of their coflows by lying about the coflow information. Thus, it is a common belief that optimizing coflow performance can inevitably violate strategy-proofness.

In this paper, we argue that the average CCT can be reduced without violating strategy-proofness. Our key insight is that prioritization can inherently achieve better CCT even without those specific rules such as smallest-effective-bottleneck-first. We propose RICH, a coflow scheduler in non-cooperative environments. At its heart, RICH splits the time into multiple rounds. In each round, RICH ensures that the total data transmitted by each tenant can provide optimal isolation guarantee. Among different rounds, RICH prioritizes coflow transmission among tenants in a round-robin manner. In this way, all tenants are fairly prioritized, and tenants do not necessarily gain more bandwidth by cheating. Extensive simulations show that RICH outperforms other strategy-proof mechanisms by up to 39.3% in terms of average CCT.

Coflow 调度可以有效地提高应用程序性能，并且已经在协作环境（例如私有数据中心网络）中进行了大量研究，其中公平性不是主要关注点。在非合作环境中（例如，多租户数据中心网络），coflow 调度应该是策略证明；否则，一些租户可以通过欺骗调度程序来不公平地获取更多资源。由于最小化 coflow 完成时间 (CCT) 必须根据某些特定规则（例如，最短 coflow 优先，最小有效瓶颈优先）对 coflow 进行优先级排序，因此租户可以通过对 coflow 信息撒谎来提高其 coflow 的优先级。因此，人们普遍认为优化 coflow 性能不可避免地会违反策略证明。

在本文中，我们认为可以在不违反策略证明的情况下降低平均 CCT。我们的关键见解是，即使没有诸如最小有效瓶颈优先之类的特定规则，优先级也可以从本质上实现更好的 CCT。我们建议RICH，非合作环境中的协流调度器。从本质上讲，RICH 将时间分成多轮。在每一轮中，RICH 确保每个租户传输的总数据可以提供最佳的隔离保证。在不同的轮次中，RICH 以循环的方式优先考虑租户之间的协流传输。这样，所有租户都得到了相当的优先权，租户不一定通过作弊获得更多的带宽。大量模拟表明，就平均 CCT 而言，RICH 的性能优于其他策略证明机制高达 39.3%。