def test_migration_checkpoint_removal(start_connected_emptyhead_cluster,
tmpdir, durable):
"""Test checks that trial restarts if checkpoint is lost w/ node fail."""
cluster = start_connected_emptyhead_cluster
node = cluster.add_node(num_cpus=1)
cluster.wait_for_nodes()
if durable:
upload_dir = "file://" + str(tmpdir)
syncer_callback = SyncerCallback()
else:
upload_dir = None
syncer_callback = custom_driver_logdir_callback(str(tmpdir))
runner = TrialRunner(BasicVariantGenerator(), callbacks=[syncer_callback])
kwargs = {
"stopping_criterion": {
"training_iteration": 4
},
"checkpoint_freq": 2,
"max_failures": 2,
"remote_checkpoint_dir": upload_dir,
}
# Test recovery of trial that has been checkpointed
t1 = Trial("__fake", **kwargs)
runner.add_trial(t1)
# Start trial, process result (x2), process save
while not t1.has_checkpoint():
runner.step()
cluster.add_node(num_cpus=1)
cluster.remove_node(node)
cluster.wait_for_nodes()
# Remove checkpoint on "remote" node
shutil.rmtree(os.path.dirname(t1.checkpoint.dir_or_data))
if not durable:
# Recover from driver file
t1.checkpoint.dir_or_data = os.path.join(
tmpdir,
t1.relative_logdir,
os.path.relpath(t1.checkpoint.dir_or_data, t1.logdir),
)
while not runner.is_finished():
runner.step()
assert t1.status == Trial.TERMINATED, runner.debug_string()
def test_trial_migration(start_connected_emptyhead_cluster, tmpdir, durable):
"""Removing a node while cluster has space should migrate trial.
The trial state should also be consistent with the checkpoint.
"""
cluster = start_connected_emptyhead_cluster
node = cluster.add_node(num_cpus=1)
cluster.wait_for_nodes()
if durable:
upload_dir = "file://" + str(tmpdir)
syncer_callback = SyncerCallback()
else:
upload_dir = None
syncer_callback = custom_driver_logdir_callback(str(tmpdir))
runner = TrialRunner(BasicVariantGenerator(), callbacks=[syncer_callback])
kwargs = {
"stopping_criterion": {
"training_iteration": 4
},
"checkpoint_freq": 2,
"max_failures": 2,
"remote_checkpoint_dir": upload_dir,
}
# Test recovery of trial that hasn't been checkpointed
t = Trial("__fake", **kwargs)
runner.add_trial(t)
runner.step() # Start trial
runner.step() # Process result
assert t.last_result
node2 = cluster.add_node(num_cpus=1)
cluster.remove_node(node)
cluster.wait_for_nodes()
# TODO(ujvl): Node failure does not propagate until a step after it
# actually should. This is possibly a problem with `Cluster`.
runner.step()
runner.step() # Recovery step
# TODO(rliaw): This assertion is not critical but will not pass
# because checkpoint handling is messy and should be refactored
# rather than hotfixed.
# assert t.last_result is None, "Trial result not restored correctly."
# Process result (x2), process save, process result (x2), process save
while not runner.is_finished():
runner.step()
assert t.status == Trial.TERMINATED, runner.debug_string()
# Test recovery of trial that has been checkpointed
t2 = Trial("__fake", **kwargs)
runner.add_trial(t2)
# Start trial, process result (x2), process save
while not t2.has_checkpoint():
runner.step()
node3 = cluster.add_node(num_cpus=1)
cluster.remove_node(node2)
cluster.wait_for_nodes()
while not runner.is_finished():
runner.step()
assert t2.status == Trial.TERMINATED, runner.debug_string()
# Test recovery of trial that won't be checkpointed
kwargs = {
"stopping_criterion": {
"training_iteration": 3
},
"remote_checkpoint_dir": upload_dir,
}
t3 = Trial("__fake", **kwargs)
runner.add_trial(t3)
runner.step() # Start trial
runner.step() # Process result 1
cluster.add_node(num_cpus=1)
cluster.remove_node(node3)
cluster.wait_for_nodes()
while not runner.is_finished():
runner.step()
assert t3.status == Trial.ERROR, runner.debug_string()
with pytest.raises(TuneError):
runner.step()
