{"id":24143,"library":"oneccl","title":"Intel oneAPI Collective Communications Library (oneCCL)","description":"Intel oneAPI Collective Communications Library (oneCCL) provides an efficient implementation of communication patterns used in deep learning. Version 2022.0.0 is distributed as a runtime environment package for Python, typically used with Intel optimizations for distributed training. Release cadence is tied to Intel oneAPI annual releases.","status":"active","version":"2022.0.0","language":"python","source_language":"en","source_url":"https://github.com/oneapi-src/oneCCL","tags":["distributed computing","deep learning","intel","hpc","MPI","collective communications"],"install":[{"cmd":"pip install oneccl","lang":"bash","label":"PyPI"}],"dependencies":[],"imports":[{"wrong":"import oneccl_bindings as ccl","symbol":"ccl","correct":"import oneccl_bindings as ccl"}],"quickstart":{"code":"import torch.distributed as dist\nimport oneccl_bindings as ccl\nimport os\n\n# Initialize process group with oneCCL backend\ndist.init_process_group(\n    backend='ccl',\n    init_method='env://',\n    rank=int(os.environ.get('RANK', 0)),\n    world_size=int(os.environ.get('WORLD_SIZE', 1))\n)\n\nif dist.get_rank() == 0:\n    print(\"oneCCL initialized successfully\")","lang":"python","description":"Initializes a PyTorch distributed process group using the CCL backend (oneCCL). Requires environment variables RANK, WORLD_SIZE, MASTER_ADDR, MASTER_PORT to be set."},"warnings":[{"fix":"Install oneccl_bindings via conda: conda install -c intel oneccl_bindings_pt (for PyTorch) or use the full Intel AI Kit.","message":"The pip package 'oneccl' is a runtime environment (no Python code). You must install 'oneccl_bindings' separately or use the Intel conda channel to get the actual bindings.","severity":"gotcha","affected_versions":"all"},{"fix":"Use 'import oneccl_bindings' and set backend='ccl' in torch.distributed.init_process_group.","message":"oneCCL 2022.0.0 changed backend initialization: the backend name was renamed from 'ccl' to 'ccl' (still 'ccl') but the package structure changed. Old imports from 'oneccl_bindings_for_pytorch' no longer exist.","severity":"breaking","affected_versions":">=2022.0.0"},{"fix":"Replace 'import oneccl_bindings_for_pytorch' with 'import oneccl_bindings'.","message":"The older 'oneccl_bindings_for_pytorch' package is deprecated; use the unified 'oneccl_bindings'.","severity":"deprecated","affected_versions":">=2021.3"},{"fix":"Use Linux (preferably with Intel MPI installed). For Windows, consider WSL2.","message":"oneCCL is only supported on Linux and requires MPI or a compatible runtime (e.g., Intel MPI). Windows users may encounter DLL errors.","severity":"gotcha","affected_versions":"all"}],"env_vars":null,"search_vec":"'2022.0.0':25 'annual':50 'cadenc':44 'collect':3,9,59 'communic':4,10,18,60 'comput':53 'deep':22,54 'distribut':27,41,52 'effici':15 'environ':31 'hpc':57 'implement':16 'intel':1,7,38,48,56 'learn':23,55 'librari':5,11 'mpi':58 'oneapi':2,8,49 'oneccl':6,12 'optim':39 'packag':32 'pattern':19 'provid':13 'python':34 'releas':43,51 'runtim':30 'tie':46 'train':42 'typic':35 'use':20,36 'version':24","created_at":"2026-05-01T08:11:31.076971+00:00","updated_at":"2026-05-01T08:11:31.076971+00:00","problems":{"verify_error":"Traceback (most recent call last):\n  File \"<string>\", line 1, in <module>\nModuleNotFoundError: No module named 'oneccl_bindings'"},"ecosystem":"pypi","meta_description":null,"install_score":null,"quickstart_score":null,"quickstart_tag":null,"pypi_latest":"2022.0.0","cli_name":"","cli_version":null,"type":"library","homepage":"https://software.intel.com/en-us/articles/empowering-science-with-high-performance-python","github":null,"docs":null,"changelog":null,"pypi":"https://pypi.org/project/oneccl/","npm":null,"openapi_spec":null,"status_page":null,"smithery":null,"categories":["ai-ml"],"base_url":null,"auth_type":null,"provenance":{"verified_status":"import_fail","verified_at":"2026-07-03","last_verified":"2026-07-03","next_check":"2026-07-10","install_tag":null}}