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• Unified Communication X
  • Using UCX
    • Building and Running Internal Unit Tests
    • UCX Performance Test
  • Our Community
  • Licenses
  • Contributor Agreement and Guidelines
  • UCX Publications
  • UCX Architecture
  • Supported Transports
  • Supported CPU Architectures

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Unified Communication X

Unified Communication X (UCX) provides an optimized communication layer for Message Passing (MPI), PGAS/OpenSHMEM libraries and RPC/data-centric applications.

UCX utilizes high-speed networks for inter-node communication, and shared memory mechanisms for efficient intra-node communication.

Using UCX

Building and Running Internal Unit Tests

$ ./autogen.sh
$ ./contrib/configure-devel
$ make
$ make -C test/gtest test

UCX Performance Test

Start server:

$ ./src/tools/perf/ucx_perftest -c 0

Connect client:

$ ./src/tools/perf/ucx_perftest <server-hostname> -t tag_lat -c 0

Our Community

• Project Website
• Github
• Software Releases
• Mailing List
• Twitter

Licenses

UCX is licensed as:

• BSD3

Contributor Agreement and Guidelines

In order to contribute to UCX, please sign up with an appropriate Contributor Agreement.

Follow these instructions when submitting contributions and changes.

UCX Publications

To reference UCX in a publication, please use the following entry:

@inproceedings{shamis2015ucx,
  title={UCX: an open source framework for HPC network APIs and beyond},
  author={Shamis, Pavel and Venkata, Manjunath Gorentla and Lopez, M Graham and Baker, Matthew B and Hernandez, Oscar and Itigin, Yossi and Dubman, Mike and Shainer, Gilad and Graham, Richard L and Liss, Liran and others},
  booktitle={2015 IEEE 23rd Annual Symposium on High-Performance Interconnects},
  pages={40--43},
  year={2015},
  organization={IEEE}
}

To reference the UCX website:

@misc{openucx-website,
    title = {{The Unified Communication X Library}},
    key = {{{The Unified Communication X Library}},
    howpublished = {{\url{http://www.openucx.org}}}
}

UCX Architecture

Component	Role	Description
UCP	Protocol	Implements high-level abstractions such as tag-matching, streams, connection negotiation and establishment, multi-rail, and handling different memory types
UCT	Transport	Implements low-level communication primitives such as active messages, remote memory access, and atomic operations
UCS	Services	A collection of data structures, algorithms, and system utilities for common use
UCM	Memory	Intercepts memory allocation and release events, used by the memory registration cache

Supported Transports

• Infiniband
• Omni-Path
• RoCE
• Cray Gemini and Aries
• CUDA
• ROCm
• Shared Memory
  • posix, sysv, cma, knem, and xpmem
• TCP/IP

Supported CPU Architectures

• x86_64
• Power8/9
• Arm v8

Huawei Optimization Introduction

Based on performance consideration, UCX DO NOT provide the functionalities related to transmission security.

There are three optimized collective operations:

• MPI_Allreduce
• MPI_Bcast
• MPI_Barrier

New algorithms are as follows:

• Binomial tree
• Ring
• Recursive
• Topo-aware Binomial tree
• Topo-aware K-nomial tree
• Topo-aware Recursive + Binomial(intra)
• Topo-aware Recursive + K-nomial(intra)

Select specific algorithm with parameters which is showed in the table below.

Bcast:

UCX_BUILTIN_BCAST_ALGORITHM	Algorithm
1	Binomial tree
2	Topo-aware Binomial tree
3	Topo-aware K-nomial tree
4	Topo-aware K-nomial tree + Binomial tree(intra)

Allreduce:

UCX_BUILTIN_ALLREDUCE_ALGORITHM	Algorithm
1	Recursive
2	Topo-aware Recursive + Binomial(intra)(Node)
3	Topo-aware Recursive + Binomial(intra)(Socket)
4	Ring
5	Topo-aware Recursive + K-nomial (intra)(Node)
6	Topo-aware Recursive + K-nomial (intra)(Socket)
7	Topo-aware K-nomial(Node)
8	Topo-aware K-nomial(Socket)

Barrier:

UCX_BUILTIN_BARRIER_ALGORITHM	Algorithm
1	Recursive
2	Topo-aware Recursive + Binomial(intra)(Node)
3	Topo-aware Recursive + Binomial(intra)(Socket)
4	Topo-aware Recursive + K-nomial (intra)(Node)
5	Topo-aware Recursive + K-nomial (intra)(Socket)
6	Topo-aware K-nomial(Node)
7	Topo-aware K-nomial(Socket)