RDMA
Remote Direct Memory Access (RDMA) is a networking technology that allows direct access to the memory of another computer without involving the remote computer's operating system or CPU. This direct access results in lower latency and higher throughput, as it bypasses the traditional protocol stack, reducing the amount of processing overhead.
RDMA was developed to address the increasing need for efficient and high-performance data transfer in modern computing environments, particularly in high-performance computing (HPC), data centers, and cloud computing. RDMA supports various transport protocols, including InfiniBand, RoCE (RDMA over Converged Ethernet), and iWARP (Internet Wide Area RDMA Protocol).
Key features of RDMA include:
- Direct data transfer: RDMA enables data to be transferred directly from the memory of one computer to another, bypassing the CPU, cache, and operating system of both systems. This reduces the overhead and improves overall system performance.
- Zero-copy: With RDMA, data can be sent directly from the application's memory to the network, eliminating the need for intermediate data copying and reducing the load on the CPU.
- Asynchronous operation: RDMA supports asynchronous data transfer, allowing applications to continue processing while data is being transferred in the background.
- Scalability: RDMA is highly scalable, making it suitable for large-scale, distributed computing environments.
RDMA is widely used in various applications, such as HPC, data center networking, storage area networks (SANs), and distributed file systems. It helps improve performance, reduce latency, and increase the efficiency of data-intensive applications.