def start(self):
"""Starts the Horovod driver and services."""
self.rendezvous = RendezvousServer(self.settings.verbose)
self.driver = ElasticDriver(rendezvous=self.rendezvous,
discovery=self.settings.discovery,
min_np=self.settings.min_np,
max_np=self.settings.max_np,
timeout=self.settings.elastic_timeout,
reset_limit=self.settings.reset_limit,
verbose=self.settings.verbose)
handler = create_rendezvous_handler(self.driver)
global_rendezv_port = self.rendezvous.start(handler)
self.driver.wait_for_available_slots(self.settings.num_proc)
# Host-to-host common interface detection
# requires at least 2 hosts in an elastic job.
min_hosts = _get_min_start_hosts(self.settings)
current_hosts = self.driver.wait_for_available_slots(
self.settings.num_proc, min_hosts=min_hosts)
nics = driver_service.get_common_interfaces(
self.settings, current_hosts.host_assignment_order)
server_ip = network.get_driver_ip(nics)
self.run_env_vars = create_run_env_vars(server_ip,
nics,
global_rendezv_port,
elastic=True)
def launch_gloo_elastic(command, exec_command, settings, env,
get_common_interfaces, rendezvous):
# Make the output directory if it does not exist
if settings.output_filename:
_mkdir_p(settings.output_filename)
driver = ElasticDriver(rendezvous,
settings.discovery,
settings.min_np,
settings.max_np,
timeout=settings.elastic_timeout,
reset_limit=settings.reset_limit,
cooldown_range=settings.cooldown_range,
verbose=settings.verbose)
handler = create_rendezvous_handler(driver)
global_rendezv_port = rendezvous.start(handler)
driver.wait_for_available_slots(settings.num_proc)
nics = get_common_interfaces(driver)
server_ip = network.get_driver_ip(nics)
event = register_shutdown_event()
run_command = get_run_command(command,
server_ip,
nics,
global_rendezv_port,
elastic=True)
create_worker = _create_elastic_worker_fn(exec_command, run_command, env,
event)
driver.start(settings.num_proc, create_worker)
res = driver.get_results()
driver.stop()
if res.error_message is not None:
raise RuntimeError(res.error_message)
for name, value in sorted(res.worker_results.items(),
key=lambda item: item[1][1]):
exit_code, timestamp = value
if exit_code != 0:
raise RuntimeError(
'Horovod detected that one or more processes exited with non-zero '
'status, thus causing the job to be terminated. The first process '
'to do so was:\nProcess name: {name}\nExit code: {code}\n'.
format(name=name, code=exit_code))
def gloo_run_fn():
driver_ip = network.get_driver_ip(nics)
gloo_run(settings, nics, env, driver_ip, command)
def _run_static(args):
nics_set = set(args.nics.split(',')) if args.nics else None
# horovodrun has to finish all the checks before this timeout runs out.
if args.start_timeout:
start_timeout = args.start_timeout
else:
# Lookup default timeout from the environment variable.
start_timeout = int(os.getenv('HOROVOD_START_TIMEOUT', '30'))
tmout = timeout.Timeout(start_timeout,
message='Timed out waiting for {activity}. Please '
'check connectivity between servers. You '
'may need to increase the --start-timeout '
'parameter if you have too many servers.')
settings = hvd_settings.Settings(verbose=2 if args.verbose else 0,
ssh_port=args.ssh_port,
ssh_identity_file=args.ssh_identity_file,
extra_mpi_args=args.mpi_args,
tcp_flag=args.tcp_flag,
binding_args=args.binding_args,
key=secret.make_secret_key(),
start_timeout=tmout,
num_proc=args.np,
hosts=args.hosts,
output_filename=args.output_filename,
run_func_mode=args.run_func is not None,
nics=nics_set)
# This cache stores the results of checks performed by horovod
# during the initialization step. It can be disabled by setting
# --disable-cache flag.
fn_cache = None
if not args.disable_cache:
params = ''
if args.np:
params += str(args.np) + ' '
if args.hosts:
params += str(args.hosts) + ' '
if args.ssh_port:
params += str(args.ssh_port)
if args.ssh_identity_file:
params += args.ssh_identity_file
parameters_hash = hashlib.md5(params.encode('utf-8')).hexdigest()
fn_cache = cache.Cache(CACHE_FOLDER, CACHE_STALENESS_THRESHOLD_MINUTES,
parameters_hash)
all_host_names, _ = hosts.parse_hosts_and_slots(args.hosts)
if settings.verbose >= 2:
print('Filtering local host names.')
remote_host_names = network.filter_local_addresses(all_host_names)
if settings.verbose >= 2:
print('Remote host found: ' + ' '.join(remote_host_names))
if len(remote_host_names) > 0:
if settings.verbose >= 2:
print('Checking ssh on all remote hosts.')
# Check if we can ssh into all remote hosts successfully.
if not _check_all_hosts_ssh_successful(remote_host_names,
args.ssh_port,
args.ssh_identity_file,
fn_cache=fn_cache):
raise RuntimeError('could not connect to some hosts via ssh')
if settings.verbose >= 2:
print('SSH was successful into all the remote hosts.')
nics = driver_service.get_common_interfaces(settings, all_host_names,
remote_host_names, fn_cache)
if args.run_func:
# get the driver IPv4 address
driver_ip = network.get_driver_ip(nics)
run_func_server = KVStoreServer(verbose=settings.verbose)
run_func_server_port = run_func_server.start_server()
put_data_into_kvstore(driver_ip, run_func_server_port, 'runfunc',
'func', args.run_func)
command = [
sys.executable, '-m', 'horovod.runner.run_task',
str(driver_ip),
str(run_func_server_port)
]
try:
_launch_job(args, settings, nics, command)
results = [None] * args.np
# TODO: make it parallel to improve performance
for i in range(args.np):
results[i] = read_data_from_kvstore(driver_ip,
run_func_server_port,
'runfunc_result', str(i))
return results
finally:
run_func_server.shutdown_server()
else:
command = args.command
_launch_job(args, settings, nics, command)
return None
def launch_gloo_elastic(command_or_func, exec_command, settings, env, get_common_interfaces, rendezvous, executable):
# Make the output directory if it does not exist
if settings.output_filename:
_mkdir_p(settings.output_filename)
driver = ElasticDriver(rendezvous, settings.discovery,
settings.min_num_proc, settings.max_num_proc,
timeout=settings.elastic_timeout,
reset_limit=settings.reset_limit,
cooldown_range=settings.cooldown_range,
verbose=settings.verbose)
handler = create_rendezvous_handler(driver)
global_rendezv_port = rendezvous.start(handler)
driver.wait_for_available_slots(settings.num_proc)
nics = get_common_interfaces(driver)
server_ip = network.get_driver_ip(nics)
run_func_server = None
run_func_server_port = None
if settings.run_func_mode:
# when running a func, we have to spin up the KVStoreServer
# to get the func to the remote process and the result back
run_func_server = KVStoreServer(verbose=settings.verbose)
run_func_server_port = run_func_server.start_server()
put_data_into_kvstore(server_ip, run_func_server_port, 'runfunc', 'func', command_or_func)
command = [executable, '-m', 'horovod.runner.run_task', server_ip, str(run_func_server_port)]
else:
command = command_or_func
try:
event = register_shutdown_event()
run_command = get_run_command(command, server_ip, nics, global_rendezv_port, elastic=True)
create_worker = _create_elastic_worker_fn(exec_command, run_command, env, event)
driver.start(settings.num_proc, create_worker)
res = driver.get_results()
driver.stop()
if res.error_message is not None:
raise RuntimeError(res.error_message)
for name, value in sorted(res.worker_results.items(), key=lambda item: item[1][1]):
exit_code, timestamp = value
if exit_code != 0:
raise RuntimeError('Horovod detected that one or more processes exited with non-zero '
'status, thus causing the job to be terminated. The first process '
'to do so was:\nProcess name: {name}\nExit code: {code}\n'
.format(name=name, code=exit_code))
# fetch the result if running a func
if settings.run_func_mode:
results = [None] * settings.min_num_proc
# TODO: make it parallel to improve performance
for i in range(settings.min_num_proc):
results[i] = read_data_from_kvstore(server_ip, run_func_server_port, 'runfunc_result', str(i))
return results
return None
finally:
if run_func_server:
run_func_server.shutdown_server()
def test_worker_notification_manager(self):
"""Tests that host add events are sent to the worker notification service and consumed."""
slots = {'host-1': 2}
discovery = FixedHosts(slots)
rendezvous = RendezvousServer()
driver = ElasticDriver(rendezvous, discovery, min_np=2, max_np=4)
driver.wait_for_available_slots(min_np=2)
handler = create_rendezvous_handler(driver)
common_intfs = network.get_local_intfs()
addr = network.get_driver_ip(common_intfs)
port = rendezvous.start(handler)
nic = list(common_intfs)[0]
rank_results = {}
class NotificationReceiver:
def __init__(self):
self.events = []
def on_hosts_updated(self, timestamp, res):
self.events.append((timestamp, res))
def add_host():
slots = {'host-1': 2, 'host-2': 2}
discovery.set(slots)
def remove_host():
slots = {'host-2': 2}
discovery.set(slots)
def exec_command(slot_info, events):
manager = WorkerNotificationManager()
manager.init(rendezvous_addr=addr,
rendezvous_port=port,
nic=nic,
hostname=slot_info.hostname,
local_rank=slot_info.local_rank)
notification_receiver = NotificationReceiver()
manager.register_listener(notification_receiver)
driver.record_ready(slot_info.hostname, slot_info.local_rank)
if slot_info.rank == 0:
add_host()
driver.wait_for_available_slots(4)
if slot_info.rank == 0:
remove_host()
# Busy wait for the number of available slots to decrease
while driver._host_manager.current_hosts.count_available_slots(
) > 2:
time.sleep(0.01)
rank_results[slot_info.rank] = notification_receiver.events
return 0, time.time()
driver.start(np=2, create_worker_fn=exec_command)
res = driver.get_results().worker_results
driver.stop()
assert len(res) == 2
for name, (exit_code, timestamp) in res.items():
assert exit_code == 0, name
assert len(rank_results) == 2
for rank, events in rank_results.items():
expected = 2 if rank == 0 else 0
assert len(events) == expected, rank
if rank == 0:
# First update is an add
assert events[0][1] == HostUpdateResult.added
# Second update is a removal
assert events[1][1] == HostUpdateResult.removed
rendezvous.stop()
