Unified Communication X

Unified Communication X (UCX) is anaward winning,optimized production proven-communication framework for modern, high-bandwidthand low-latency networks.

UCX exposes a set of abstract communication primitives that utilize the best ofavailable hardware resources and offloads. These include RDMA (InfiniBand and RoCE),TCP, GPUs, shared memory, and network atomic operations.

Please visit our documentation sitefor more details.

Please review our "Membership Voluntary Consensus Standard" and"Export Compliant Contribution Submissions" policies.

• Using UCX
• Known issues
• Architecture
• Supported Transports
• Supported CPU Architectures
• Licenses
• Our Community
• Contributor Agreement and Guidelines
• Publications

Using UCX

Release Builds

Building UCX is typically a combination of running "configure" and "make".Execute the following commands to install the UCX system from within thedirectory at the top of the tree:

$ ./autogen.sh
$ ./contrib/configure-release --prefix=/where/to/install
$ make -j8
$ make install

NOTE: Compiling support for various networks or other specific hardware mayrequire additional command line flags when running configure.

Developer Builds

$ ./autogen.sh
$ ./contrib/configure-devel --prefix=$PWD/install-debug

*** NOTE: Developer builds of UCX typically include a large performancepenalty at run-time because of extra debugging code.

Build RPM package

$ contrib/buildrpm.sh -s -b

Build DEB package

$ dpkg-buildpackage -us -uc

Build Doxygen documentation

$ make docs

OpenMPI and OpenSHMEM installation with UCX

Wiki page

MPICH installation with UCX

Wiki page

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 1

NOTE the -c flag sets CPU affinity. If running both >commands on same host, make sure you set the affinity to different CPU cores.

Running internal unit tests

$ make -C test/gtest test

Known issues

• UCX version 1.8.0 has a bug that may cause data corruption when TCP transportis used in conjunction with shared memory transport. It is advised to upgradeto UCX version 1.9.0 and above. UCX versions released before 1.8.0 don't havethis bug.

• UCX may hang with glibc versions 2.25-2.29 due to known bugs in thepthread_rwlock functions. When such hangs occur, one of the UCX threads getsstuck in pthread_rwlock_rdlock (which is called by ucs_rcache_get), eventhough no other thread holds the lock. A related issue is reported inglibc Bug 23844.If this issue occurs, it is advised to use glibc version provided with yourOS distribution or build glibc from source using versions less than 2.25 orgreater than 2.29.

Architecture

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

Licenses

UCX is licensed as:

• BSD3

Our Community

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

Contributor Agreement and Guidelines

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

All contributors have to comply with "Membership VoluntaryConsensus Standard" and "Export CompliantContribution Submissions" policies.

Follow theseinstructionswhen submitting contributions and changes.

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}}}
}