FSQCN: Fast and simple quantized congestion notification in data center ethernet
FSQCN: Fast and simple quantized congestion notification in data center ethernet
复制标题
FSQCN：数据中心以太网中快速、简单的量化拥塞通知
DOI：
10.1016/j.jnca.2017.01.025
复制
发表时间：
2017
影响因子：
8.7
通讯作者：
Pan Yi
中科院分区：
文献类型：
--
作者：
Ruan Chang;Wang Jianxin;Jiang Wanchun;Huang Jiawei;Min Geyong;Pan Yi
目前，量化拥塞通知（QCN）已被公认为数据中心以太网的标准第二层拥塞控制协议。在这项研究中，我们发现QCN有两个缺点。首先，QCN的不完全二分搜索可能无法找到合适的发送速率，导致QCN的补充机制复杂。因此，增加了硬件实现的成本。第二，面对未知的网络环境，QCN的速率设置是不一致的。更具体地，发送速率被设置为初始化时的链路速率，而QCN在面对动态网络时附加地探测额外的带宽。因此，如果QCN的发送速率从较低的值增加，则QCN可能花费大量时间来获取空闲带宽。为了解决这些问题，我们提出了快速和简单的QCN（FSQCN），以下相同的框架QCN。FSQCN是对二分查找的补充，去掉了QCN中其他复杂的补充机制。因此，FSQCN比QCN更简单，更有效。此外，当交换机检测到空闲带宽时，FSQCN会显式地将发送速率重置为链路速率。大量的仿真实验验证了FSQCN能像QCN一样很好地控制队列长度，并且响应速度比QCN快，特别是在数据中心网络中面对大量突发短流时。
Currently, Quantized Congestion Notification (QCN) has been accepted as the standard layer 2 congestion control protocol in Data Center Ethernet. In this study, we find that QCN has two drawbacks. First, the incomplete binary search of QCN may fail to find the proper sending rate, leading to the complicate supplement mechanisms of QCN. Accordingly, the cost of hardware implementation is increased. Second, in face of unknown network environments, the rate setting of QCN is inconsistent. More specifically, the sending rate is set to be the link rate at initialization, while QCN additively probes for extra bandwidth in face of dynamic network. Consequently, QCN may spend much time on acquiring the spare bandwidth if its sending rate is increased from a low value. To address these problems, we propose the Fast and Simple QCN (FSQCN), following the same framework as QCN. FSQCN complements the binary search and removes other complicate supplement mechanisms in QCN. Thus, FSQCN is much simpler and more efficient than QCN. Moreover, FSQCN resets the sending rate to the link rate explicitly when the switch detects spare bandwidth. Extensive simulation experiments validate that FSQCN controls the queue length well like QCN, and responds faster than QCN, especially in face of the large number of burst short flows in data center networks.