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Questions tagged [rdma]

RDMA refers to "Remote Direct Memory Access," which is a set of networking technologies typically used for high performance, low latency communication.

RDMA refers to "Remote Direct Memory Access," which is a set of networking technologies typically used for high performance, low latency communication.

RDMA networks have three main attributes:

  1. Asynchronous queueing: network operations are submitted by adding requests "work queues" which are asynchronously executed by hardware; when complete, the result is returned to software in a "completion queue."
  2. Kernel bypass: userspace processes can submit operations directly to the network adapter hardware without any system calls.
  3. One-sided operations: one system can read from or write into the memory of a remote system without involving any software on the remote system.
177 questions
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Multithreaded use of a single QP vs multiple QPs to improve throughput

I am using RDMA writes in my application and want to improve throughput. Currently, I have a single thread using my queue pair. I was wondering, what is a more standard way (or what are the advantages of each): Creating more connections with the…
Mihir Shah
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RDMA Read protection for local memory operations

I have the following scenario: My server allocates a buffer of 1MB, which is periodically updated and written to (about every 50ms). The client is connected to the the server via Infiniband and periodically reads that buffer via RDMA Read…
hey0
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C++: Which weak atomic to use for buffers that receive async. RDMA transfers?

The Derecho system (open-source C++ library for data replication, distributed coordination, Paxos -- ultra-fast) is built around asynchronous RDMA networking primitives. Senders can write to receivers without pausing, using RDMA transfers into…
Ken Birman
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What is the difference b/w RDMA_CREATE_QP/RDMA_CREATE_EP and IBV_CREATE_QP?

As far as I understand, IBV_CREATE_QP() and RDMA_CREATE_QP literally do the same thing. If I have called ibv_create_qp() first, do I still need to call the other one when I'm establishing a connection using ibrdmacm API? Moreover, diff b/w create…
Barney_su
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RDMA setup in AWS

I'm quite beginner with AWS, and I need to set up RDMA connectivity between client and server. Can anybody give me any idea, hint, guide or anything that helps me ? Thank you
Ben Eslami
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RDMA over native Infiniband

Is it possible to use RDMA over native InfiniBand without IPoIB (using just guid or lid)? I have checked Infiniband addressing - host names to IB address without IBoIP and in RDMA Connection Manager source files to create connection between ports…
mat300
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RDMA Scatter/Gather in verbs API

RDMA Scatter/Gather is a nice way to consolidate data transfers. For example, verbs API allows data at multiple locations to be written in a remote buffer with a SINGLE RDMA write operation; or, data in a remote buffer could be read to multiple…
Weijia Song
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rdma unexpected CM event 3 - RDMA_CM_EVENT_ROUTE_ERROR

I am hosting an Infiniband server in a linux machine and also I have created a client and connected to that service in the same machine.This works fine most of the time. But in one instance when I was trying to connect to that server from the same…
Kethiri Sundar
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Mapping remote memory into the address space of a host using Inifiniband

I recently started to work with Infiniband cards, two Mellanox Technologies MT27700 Family [ConnectX-4] to be specific. Eventually, I want to extend an existing framework with interfaces based on the VPI Verbs API/RDMA CM API. About the research I…
Silicon1602
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MVAPICH2 RDMA-based communication without explicit PUT/GET use?

My cluster utilizes MVAPICH2 over Infiniband FDR and and I am considering the use of RDMA for my simulations. I am aware of the MPI_Put and MPI_Get calls for explicitly invoking RDMA operations, however I would like to know if this is the only way…
Tokth
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InfiniBand RDMA

I am trying to use the InfiniBand on an A8 machine on Azure. Actually, the ping-pong test works fine however, I can not run a simple RDMA based program. I can find the device by ibv_get_device_list(NULL) but I can not open it by the…
masoud
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How to develop with rsocket

I'm trying to use RDMA over infiniband as part of an application. I've discovered rsocket which looks like a useful API for RDMA. However I'm trying to use it but I have no idea what library I'm supposed to link with. I have rdma/rsocket.h included…
thegoldencanary
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memory protection in Remote Direct Memory Access (RDMA)

Let's say I have a process that registers a piece of RDMA-accessible memory with LOCAL WRITE permission. Does another (local) random process has the write permission to that piece of physical memory?
HuangJie
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Equivalent of IBM's JVerb in Oracle for RDMA in Java

What is the equivalent of IBM's JVerb in Oracle, if I want to employ RoCE protocol for RDMA over Ethernet? Edit: Perhaps, JXIO is my best option?
GuSuku
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rsocket - RDMA socket API - client unable to connect to server

I have written simple client & server program using rsocket - RDMA socket API using following version of librdmacm-dev & librdmacm1 package (using Ubuntu 14.04): librdmacm1/trusty 1.0.16-1 i386 librdmacm-dev/trusty 1.0.16-1 i386 When server is…
Vikram Chouhan
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