openstack/deb-python-taskflow
Code Issues Proposed changes

Ensure we change the self and parents states correctly.

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Change the state of the current flow in the rollback method
itself so that if we have parent workflows they also get there
states changed.
This commit is contained in:
Joshua Harlow
2013-05-22 14:25:11 -07:00
parent 2962ecb9ab
commit d4f74720cb
1 changed files with 34 additions and 30 deletions
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64
taskflow/patterns/ordered_flow.py
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@@ -107,12 +107,6 @@ class Flow(object):
# some type of undo of the tasks already completed.
cause = FlowFailure(task, self, excp)
with excutils.save_and_reraise_exception():
try:
self._change_state(context, states.REVERTING)
except Exception:
LOG.exception("Dropping exception catched when"
" changing state to reverting while performing"
" reconcilation on a tasks exception.")
try:
self._on_task_error(context, task)
except Exception:
@@ -122,15 +116,7 @@ class Flow(object):
# The default strategy will be to rollback all the contained
# tasks by calling there reverting methods, and then calling
# any parent flows rollbacks (and so-on).
try:
self.rollback(context, cause)
finally:
try:
self._change_state(context, states.FAILURE)
except Exception:
LOG.exception("Dropping exception catched when"
" changing state to failure while performing"
" reconcilation on a tasks exception.")
self.rollback(context, cause)
def run(self, context, *args, **kwargs):
if self.state != states.PENDING:
@@ -263,23 +249,41 @@ class Flow(object):
# For example, if each task was creating a file in a directory, then
# it's easier to just remove the directory than to ask each task to
# delete its file individually.
for (i, (task, result)) in enumerate(reversed(self._reversions)):
try:
self._change_state(context, states.REVERTING)
except Exception:
LOG.exception("Dropping exception catched when"
" changing state to reverting while performing"
" reconcilation on a tasks exception.")
def rollback_tasks(reversions, tolerant):
for (i, (task, result)) in enumerate(reversions):
try:
task.revert(context, result, cause)
except Exception:
# Ex: WARN: Failed rolling back stage 1 (validate_request) of
# chain validation due to Y exception.
log_f = LOG.warn
if not tolerant:
log_f = LOG.exception
msg = ("Failed rolling back stage %(index)s (%(task)s)"
" of flow %(flow)s, due to inner exception.")
log_f(msg % {'index': (i + 1), 'task': task, 'flow': self})
if not tolerant:
# NOTE(harlowja): LOG a msg AND re-raise the exception
# if the flow does not tolerate exceptions happening
# in the rollback method.
raise
try:
rollback_tasks(reversed(self._reversions), self.tolerant)
finally:
try:
task.revert(context, result, cause)
self._change_state(context, states.FAILURE)
except Exception:
# Ex: WARN: Failed rolling back stage 1 (validate_request) of
# chain validation due to Y exception.
log_f = LOG.warn
if not self.tolerant:
log_f = LOG.exception
msg = ("Failed rolling back stage %(index)s (%(task)s)"
" of flow %(flow)s, due to inner exception.")
log_f(msg % {'index': (i + 1), 'task': task, 'flow': self})
if not self.tolerant:
# NOTE(harlowja): LOG a msg AND re-raise the exception if
# the chain does not tolerate exceptions happening in the
# rollback method.
raise
LOG.exception("Dropping exception catched when"
" changing state to failure while performing"
" reconcilation on a tasks exception.")
if self.parents:
# Rollback any parents flows if they exist...
for p in self.parents: