简单的想法是将所有乱序包存储在网卡内存中,考虑到在一千条流同时发生乱序时所需的网卡内存容量远远超出目前RDMA网卡的容量,所以作者采用将乱序的包直接通过DMA方式传送到应用内存的最终位置,然后用bitmap跟踪。这种机制目前在最新的网卡中只支持write和read操作。作者通过扩展网卡将IRN部署,使其支持所有RDMA的所有操作。...
大多数流量很小(50%的数据流是单个数据包消息,大小介于32字节-1KB之间,表示小型RPC,例如基于RDMA的键值存储生成的那些[21,25]),大多数字节都在大数据流中(15%的数据流在200KB-3MB之间,代表背景RDMA数据流,如存储)。对于我们的默认情景,网络负载设置为70%利用率。 我们使用ECMP进行负载平衡[23]。 我们在§4.4...
RDMA has long been used by the HPC community in special-purpose Infniband clusters that use credit-based flow control to make the network lossless [4]. Because packet drops are rare in such clusters, the RDMA Infiniband transport (as implemented on the NIC) was not designed to efficiently...
The advent of RoCE (RDMA over Converged Ethernet) has led to a significant increase in the use of RDMA in datacenter networks. To achieve good performance, RoCE requires a lossless network which is in turn achieved by enabling Priority Flow Control (PFC) within the network. However, PFC bring...
Let’s begin with the first paper titled “FastWake: Revisiting Host Network Stack for Interrupt-mode RDMA”. The speaker is Dr. Bojie Li. Dr. Bojie Li is a technical expert with Huawei Technologies. His research interests include high-performance data center systems. Currently, he’s focusing...
Priority Flow Control (PFC) within the network. However, PFC brings with it a host of problems such as head-of-the-line blocking, congestion spreading, and occasional deadlocks. Rather than seek to fix these issues, we instead ask: is PFC fundamentally required to support RDMA over Ethernet?
Remote Direct Memory Access (RDMA) provides the ability to direct access remote user space memory without remote CPU’s involvement, shortening the network latency tremendously; in addition, a new generation of fast Non-Volatile Memory (NVM) technologies
基本架构 图片源出处 基础概念 Fabric CA QP 队列QP 四种操作 四种操作 send/ecv pull/push Verbs 参考文章 三个版本 rdma-core 开源RDMA用户态软件协议栈,包含用户态框架、各厂商用户态驱动、API帮助手册以及开发自测试工具等。 rdma-core在github上维护,用户态Verbs API的实际实现 https://github.com/lin... ...