c7dfdcef44d181ee2b834e3b0fb06c9c82f952b3,horovod/run/common/util/host_hash.py,,host_hash,#,33

Before Change

    hostname = socket.gethostname()
    ns = _namespaces()
    host_ns = hostname + "-" + ns
    hash = hashlib.md5(host_ns.encode("ascii")).hexdigest()
    return "%s-%s" % (hostname.split(".")[0], hash)

After Change

    // when running in YARN containers we need to consider a container a host
    // otherwise we might violate resource allocation if we run all tasks of a host in one container
    // see [issues 1497](https://github.com/horovod/horovod/issues/1497) for details
    container = os.environ.get("CONTAINER_ID")
    if container is not None:
        host_info = "{host_info}-{container}".format(host_info=host_info, container=container)

    return "{host}-{hash}".format(host=host, hash=_hash(host_info))

Instances