def _dispatch_workflow_commands(self, wf_ex, wf_cmds):
if not wf_cmds:
return
for cmd in wf_cmds:
if isinstance(cmd, commands.RunTask) and cmd.is_waiting():
task_handler.defer_task(cmd)
elif isinstance(cmd, commands.RunTask):
task_handler.run_new_task(cmd)
elif isinstance(cmd, commands.RunExistingTask):
task_handler.run_existing_task(
cmd.task_ex.id,
reset=cmd.reset
)
elif isinstance(cmd, commands.SetWorkflowState):
if states.is_completed(cmd.new_state):
self._stop_workflow(cmd.wf_ex, cmd.new_state, cmd.msg)
else:
wf_handler.set_execution_state(wf_ex, cmd.new_state)
elif isinstance(cmd, commands.Noop):
# Do nothing.
pass
else:
raise RuntimeError('Unsupported workflow command: %s' % cmd)
if wf_ex.state != states.RUNNING:
break
def pause_workflow(self, execution_id):
with db_api.transaction():
wf_ex = wf_handler.lock_workflow_execution(execution_id)
wf_handler.set_execution_state(wf_ex, states.PAUSED)
return wf_ex
def _continue_workflow(self, wf_ex, task_ex=None, reset=True, env=None):
wf_ex = wf_service.update_workflow_execution_env(wf_ex, env)
wf_handler.set_execution_state(wf_ex,
states.RUNNING,
set_upstream=True)
wf_ctrl = wf_base.WorkflowController.get_controller(wf_ex)
# Calculate commands to process next.
cmds = wf_ctrl.continue_workflow(task_ex=task_ex, reset=reset, env=env)
# When resuming a workflow we need to ignore all 'pause'
# commands because workflow controller takes tasks that
# completed within the period when the workflow was pause.
cmds = list(
filter(lambda c: not isinstance(c, commands.PauseWorkflow), cmds))
# Since there's no explicit task causing the operation
# we need to mark all not processed tasks as processed
# because workflow controller takes only completed tasks
# with flag 'processed' equal to False.
for t_ex in wf_ex.task_executions:
if states.is_completed(t_ex.state) and not t_ex.processed:
t_ex.processed = True
self._dispatch_workflow_commands(wf_ex, cmds)
if not cmds:
if not wf_utils.find_incomplete_task_executions(wf_ex):
wf_handler.succeed_workflow(
wf_ex, wf_ctrl.evaluate_workflow_final_context())
return wf_ex.get_clone()
def _continue_workflow(self, wf_ex, task_ex=None, reset=True):
wf_handler.set_execution_state(wf_ex, states.RUNNING)
wf_ctrl = wf_base.WorkflowController.get_controller(wf_ex)
# Calculate commands to process next.
cmds = wf_ctrl.continue_workflow(task_ex=task_ex, reset=reset)
# When resuming a workflow we need to ignore all 'pause'
# commands because workflow controller takes tasks that
# completed within the period when the workflow was pause.
cmds = filter(
lambda c: not isinstance(c, commands.PauseWorkflow),
cmds
)
# Since there's no explicit task causing the operation
# we need to mark all not processed tasks as processed
# because workflow controller takes only completed tasks
# with flag 'processed' equal to False.
for t_ex in wf_ex.task_executions:
if states.is_completed(t_ex.state) and not t_ex.processed:
t_ex.processed = True
self._dispatch_workflow_commands(wf_ex, cmds)
if not cmds:
if not wf_utils.find_incomplete_task_executions(wf_ex):
wf_handler.succeed_workflow(
wf_ex,
wf_ctrl.evaluate_workflow_final_context()
)
return wf_ex.get_clone()
def _fail_workflow(wf_ex_id, err, action_ex_id=None):
"""Private helper to fail workflow on exceptions."""
err_msg = str(err)
with db_api.transaction():
wf_ex = db_api.load_workflow_execution(wf_ex_id)
if wf_ex is None:
LOG.error(
"Cant fail workflow execution with id='%s': not found.",
wf_ex_id)
return
wf_handler.set_execution_state(wf_ex, states.ERROR, err_msg)
if action_ex_id:
# Note(dzimine): Don't call self.engine_client:
# 1) to avoid computing and triggering next tasks
# 2) to avoid a loop in case of error in transport
action_ex = db_api.get_action_execution(action_ex_id)
task_handler.on_action_complete(action_ex,
wf_utils.Result(error=err_msg))
return wf_ex
def pause_workflow(self, wf_ex_id):
with db_api.transaction():
wf_ex = wf_handler.lock_workflow_execution(wf_ex_id)
wf_handler.set_execution_state(wf_ex, states.PAUSED)
return wf_ex
def _fail_workflow(wf_ex_id, err, action_ex_id=None):
"""Private helper to fail workflow on exceptions."""
with db_api.transaction():
err_msg = str(err)
wf_ex = db_api.load_workflow_execution(wf_ex_id)
if wf_ex is None:
LOG.error(
"Cant fail workflow execution with id='%s': not found.",
wf_ex_id
)
return
wf_handler.set_execution_state(wf_ex, states.ERROR, err_msg)
if action_ex_id:
# Note(dzimine): Don't call self.engine_client:
# 1) to avoid computing and triggering next tasks
# 2) to avoid a loop in case of error in transport
action_ex = db_api.get_action_execution(action_ex_id)
task_handler.on_action_complete(
action_ex,
wf_utils.Result(error=err_msg)
)
def stop_workflow(self, execution_id, state, message=None):
with db_api.transaction():
# Must be before loading the object itself (see method doc).
self._lock_workflow_execution(execution_id)
wf_ex = db_api.get_execution(execution_id)
wf_handler.set_execution_state(wf_ex, state, message)
return wf_ex
def pause_workflow(self, execution_id):
with db_api.transaction():
# Must be before loading the object itself (see method doc).
self._lock_workflow_execution(execution_id)
wf_ex = db_api.get_workflow_execution(execution_id)
wf_handler.set_execution_state(wf_ex, states.PAUSED)
return wf_ex
def pause_workflow(self, execution_id):
with db_api.transaction():
# Must be before loading the object itself (see method doc).
self._lock_workflow_execution(execution_id)
wf_ex = db_api.get_workflow_execution(execution_id)
wf_handler.set_execution_state(wf_ex, states.PAUSED)
return wf_ex
def resume_workflow(self, execution_id):
try:
with db_api.transaction():
# Must be before loading the object itself (see method doc).
self._lock_workflow_execution(execution_id)
wf_ex = db_api.get_workflow_execution(execution_id)
if wf_ex.state != states.PAUSED:
return
wf_handler.set_execution_state(wf_ex, states.RUNNING)
wf_ctrl = wf_base.WorkflowController.get_controller(wf_ex)
# Calculate commands to process next.
cmds = wf_ctrl.continue_workflow()
# When resuming a workflow we need to ignore all 'pause'
# commands because workflow controller takes tasks that
# completed within the period when the workflow was pause.
cmds = filter(
lambda c: not isinstance(c, commands.PauseWorkflow),
cmds
)
# Since there's no explicit task causing the operation
# we need to mark all not processed tasks as processed
# because workflow controller takes only completed tasks
# with flag 'processed' equal to False.
for t_ex in wf_ex.task_executions:
if states.is_completed(t_ex.state) and not t_ex.processed:
t_ex.processed = True
self._dispatch_workflow_commands(wf_ex, cmds)
if not cmds:
if not wf_utils.find_incomplete_tasks(wf_ex):
wf_handler.succeed_workflow(
wf_ex,
wf_ctrl.evaluate_workflow_final_context()
)
return wf_ex
except Exception as e:
LOG.error(
"Failed to resume execution id=%s: %s\n%s",
execution_id, e, traceback.format_exc()
)
self._fail_workflow(execution_id, e)
raise e
def _continue_workflow(self, wf_ex, task_ex=None, reset=True, env=None):
wf_ex = wf_service.update_workflow_execution_env(wf_ex, env)
wf_handler.set_execution_state(
wf_ex,
states.RUNNING,
set_upstream=True
)
wf_ctrl = wf_base.get_controller(wf_ex)
# TODO(rakhmerov): Add YAQL error handling.
# Calculate commands to process next.
cmds = wf_ctrl.continue_workflow(task_ex=task_ex, reset=reset, env=env)
# When resuming a workflow we need to ignore all 'pause'
# commands because workflow controller takes tasks that
# completed within the period when the workflow was paused.
cmds = list(
filter(
lambda c: not isinstance(c, commands.PauseWorkflow),
cmds
)
)
# Since there's no explicit task causing the operation
# we need to mark all not processed tasks as processed
# because workflow controller takes only completed tasks
# with flag 'processed' equal to False.
for t_ex in wf_ex.task_executions:
if states.is_completed(t_ex.state) and not t_ex.processed:
t_ex.processed = True
wf_spec = spec_parser.get_workflow_spec(wf_ex.spec)
self._dispatch_workflow_commands(wf_ex, cmds, wf_spec)
if not cmds:
if not wf_utils.find_incomplete_task_executions(wf_ex):
wf_handler.succeed_workflow(
wf_ex,
wf_ctrl.evaluate_workflow_final_context(),
wf_spec
)
return wf_ex.get_clone()
def resume_workflow(self, execution_id):
try:
with db_api.transaction():
# Must be before loading the object itself (see method doc).
self._lock_workflow_execution(execution_id)
wf_ex = db_api.get_workflow_execution(execution_id)
if wf_ex.state != states.PAUSED:
return wf_ex
wf_handler.set_execution_state(wf_ex, states.RUNNING)
wf_ctrl = wf_base.WorkflowController.get_controller(wf_ex)
# Calculate commands to process next.
cmds = wf_ctrl.continue_workflow()
# When resuming a workflow we need to ignore all 'pause'
# commands because workflow controller takes tasks that
# completed within the period when the workflow was pause.
cmds = filter(
lambda c: not isinstance(c, commands.PauseWorkflow), cmds)
# Since there's no explicit task causing the operation
# we need to mark all not processed tasks as processed
# because workflow controller takes only completed tasks
# with flag 'processed' equal to False.
for t_ex in wf_ex.task_executions:
if states.is_completed(t_ex.state) and not t_ex.processed:
t_ex.processed = True
self._dispatch_workflow_commands(wf_ex, cmds)
if not cmds:
if not wf_utils.find_incomplete_tasks(wf_ex):
wf_handler.succeed_workflow(
wf_ex, wf_ctrl.evaluate_workflow_final_context())
return wf_ex
except Exception as e:
LOG.error("Failed to resume execution id=%s: %s\n%s", execution_id,
e, traceback.format_exc())
self._fail_workflow(execution_id, e)
raise e
def start_workflow(self, wf_identifier, wf_input, description='',
**params):
wf_ex_id = None
try:
# Create a persistent workflow execution in a separate transaction
# so that we can return it even in case of unexpected errors that
# lead to transaction rollback.
with db_api.transaction():
# The new workflow execution will be in an IDLE
# state on initial record creation.
wf_ex_id, wf_spec = wf_ex_service.create_workflow_execution(
wf_identifier,
wf_input,
description,
params
)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex_id)
wf_handler.set_execution_state(wf_ex, states.RUNNING)
wf_ctrl = wf_base.get_controller(wf_ex, wf_spec)
self._dispatch_workflow_commands(
wf_ex,
wf_ctrl.continue_workflow(),
wf_spec
)
return wf_ex.get_clone()
except Exception as e:
LOG.error(
"Failed to start workflow '%s' id=%s: %s\n%s",
wf_identifier, wf_ex_id, e, traceback.format_exc()
)
wf_ex = self._fail_workflow(wf_ex_id, e)
if wf_ex:
return wf_ex.get_clone()
raise e
def _fail_workflow(wf_ex_id, exc):
"""Private helper to fail workflow on exceptions."""
with db_api.transaction():
wf_ex = db_api.load_workflow_execution(wf_ex_id)
if wf_ex is None:
LOG.error(
"Can't fail workflow execution with id='%s': not found.",
wf_ex_id
)
return None
wf_ex = wf_handler.lock_workflow_execution(wf_ex_id)
if not states.is_paused_or_completed(wf_ex.state):
wf_handler.set_execution_state(wf_ex, states.ERROR, str(exc))
return wf_ex
def _dispatch_workflow_commands(wf_ex, wf_cmds):
if not wf_cmds:
return
for cmd in wf_cmds:
if isinstance(cmd, commands.RunTask):
task_handler.run_new_task(cmd)
elif isinstance(cmd, commands.RunExistingTask):
task_handler.run_existing_task(cmd.task_ex.id)
elif isinstance(cmd, commands.SetWorkflowState):
# TODO(rakhmerov): Special commands should be persisted too.
wf_handler.set_execution_state(wf_ex, cmd.new_state)
elif isinstance(cmd, commands.Noop):
# Do nothing.
pass
else:
raise RuntimeError('Unsupported workflow command: %s' % cmd)
if wf_ex.state != states.RUNNING:
break
def _dispatch_workflow_commands(self, wf_ex, wf_cmds, wf_spec):
if not wf_cmds:
return
for cmd in wf_cmds:
if isinstance(cmd, commands.RunTask) and cmd.is_waiting():
task_handler.defer_task(cmd)
elif isinstance(cmd, commands.RunTask):
task_ex = task_handler.run_new_task(cmd, wf_spec)
if task_ex.state == states.ERROR:
wf_handler.fail_workflow(
wf_ex,
'Failed to start task [task_ex=%s]: %s' %
(task_ex, task_ex.state_info)
)
elif isinstance(cmd, commands.RunExistingTask):
task_ex = task_handler.run_existing_task(
cmd.task_ex.id,
reset=cmd.reset
)
if task_ex.state == states.ERROR:
wf_handler.fail_workflow(
wf_ex,
'Failed to start task [task_ex=%s]: %s' %
(task_ex, task_ex.state_info)
)
elif isinstance(cmd, commands.SetWorkflowState):
if states.is_completed(cmd.new_state):
self._stop_workflow(cmd.wf_ex, cmd.new_state, cmd.msg)
else:
wf_handler.set_execution_state(wf_ex, cmd.new_state)
elif isinstance(cmd, commands.Noop):
# Do nothing.
pass
else:
raise RuntimeError('Unsupported workflow command: %s' % cmd)
if wf_ex.state != states.RUNNING:
break
def start_workflow(self,
wf_identifier,
wf_input,
description='',
**params):
wf_ex_id = None
try:
with db_api.transaction():
# The new workflow execution will be in an IDLE
# state on initial record creation.
wf_ex_id = wf_ex_service.create_workflow_execution(
wf_identifier, wf_input, description, params)
# Separate workflow execution creation and dispatching command
# transactions in order to be able to return workflow execution
# with corresponding error message in state_info when error occurs
# at dispatching commands.
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex_id)
wf_spec = spec_parser.get_workflow_spec(wf_ex.spec)
wf_handler.set_execution_state(wf_ex, states.RUNNING)
wf_ctrl = wf_base.WorkflowController.get_controller(
wf_ex, wf_spec)
self._dispatch_workflow_commands(wf_ex,
wf_ctrl.continue_workflow())
return wf_ex.get_clone()
except Exception as e:
LOG.error("Failed to start workflow '%s' id=%s: %s\n%s",
wf_identifier, wf_ex_id, e, traceback.format_exc())
wf_ex = self._fail_workflow(wf_ex_id, e)
if wf_ex:
return wf_ex.get_clone()
raise e
def _dispatch_workflow_commands(self, wf_ex, wf_cmds):
if not wf_cmds:
return
for cmd in wf_cmds:
if isinstance(cmd, commands.RunTask) and cmd.is_waiting():
task_handler.defer_task(cmd)
elif isinstance(cmd, commands.RunTask):
task_handler.run_new_task(cmd)
elif isinstance(cmd, commands.RunExistingTask):
task_handler.run_existing_task(cmd.task_ex.id)
elif isinstance(cmd, commands.SetWorkflowState):
if states.is_completed(cmd.new_state):
self._stop_workflow(cmd.wf_ex, cmd.new_state, cmd.msg)
else:
wf_handler.set_execution_state(wf_ex, cmd.new_state)
elif isinstance(cmd, commands.Noop):
# Do nothing.
pass
else:
raise RuntimeError('Unsupported workflow command: %s' % cmd)
if wf_ex.state != states.RUNNING:
break