openstack/deb-python-taskflow
Code Issues Proposed changes

A few resuming from backend comment adjustments

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Change-Id: I40d8c1926b4bef337eaaf0adc6cae66d023dc200
This commit is contained in:
Joshua Harlow
2013-10-16 15:11:32 -07:00
parent b8ed518075
commit 0e75585e85
2 changed files with 60 additions and 28 deletions
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43
taskflow/examples/resume_from_backend.out.txt
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@@ -1,21 +1,26 @@
-----------------------------------
At the beginning, there is no state: At the beginning, there is no state
Flow state: None -----------------------------------
Flow 'resume from backend example' state: None
Running: -------
Running
-------
executing first==1.0 executing first==1.0
-------------
After running: After running
Flow state: SUSPENDED -------------
boom==1.0: SUCCESS, result=None Flow 'resume from backend example' state: SUSPENDED
first==1.0: SUCCESS, result=ok boom==1.0: SUCCESS, result=None
second==1.0: PENDING, result=None first==1.0: SUCCESS, result=ok
second==1.0: PENDING, result=None
Resuming and running again: --------------------------
Resuming and running again
--------------------------
executing second==1.0 executing second==1.0
----------
At the end: At the end
Flow state: SUCCESS ----------
boom==1.0: SUCCESS, result=None Flow 'resume from backend example' state: SUCCESS
first==1.0: SUCCESS, result=ok boom==1.0: SUCCESS, result=None
second==1.0: SUCCESS, result=ok first==1.0: SUCCESS, result=ok
second==1.0: SUCCESS, result=ok

45
taskflow/examples/resume_from_backend.py
View File

@@ -33,17 +33,36 @@ from taskflow.persistence import backends
from taskflow import task from taskflow import task
from taskflow.utils import persistence_utils as p_utils from taskflow.utils import persistence_utils as p_utils
# INTRO: In this example linear_flow is used to group three tasks, one which
# will suspend the future work the engine may do. This suspend engine is then
# discarded and the workflow is reloaded from the persisted data and then the
# workflow is resumed from where it was suspended. This allows you to see how
# to start an engine, have a task stop the engine from doing future work (if
# a multi-threaded engine is being used, then the currently active work is not
# preempted) and then resume the work later.
### UTILITY FUNCTIONS ######################################### ### UTILITY FUNCTIONS #########################################
def print_wrapped(text):
print("-" * (len(text)))
print(text)
print("-" * (len(text)))
def print_task_states(flowdetail, msg): def print_task_states(flowdetail, msg):
print(msg) print_wrapped(msg)
print('Flow state: %s' % flowdetail.state) # NOTE(harlowja): for this example, just avoid printing uuids so that
# we can correctly compare this output with the expected output, which
# is used by our example test verification (uuids would be different each
# time if we did not do this).
print("Flow '%s' state: %s" % (flowdetail.name, flowdetail.state))
# Sort by these so that our test validation doesn't get confused by the
# order in which the items in the flow detail can be in.
items = sorted((td.name, td.version, td.state, td.results) items = sorted((td.name, td.version, td.state, td.results)
for td in flowdetail) for td in flowdetail)
for item in items: for item in items:
print("%s==%s: %s, result=%s" % item) print(" %s==%s: %s, result=%s" % item)
def get_backend(): def get_backend():
@@ -98,20 +117,28 @@ flowdetail = p_utils.create_flow_detail(flow, logbook, backend)
engine = taskflow.engines.load(flow, flow_detail=flowdetail, engine = taskflow.engines.load(flow, flow_detail=flowdetail,
backend=backend) backend=backend)
print_task_states(flowdetail, "\nAt the beginning, there is no state:") print_task_states(flowdetail, "At the beginning, there is no state")
print("\nRunning:") print_wrapped("Running")
engine.run() engine.run()
print_task_states(flowdetail, "\nAfter running:") print_task_states(flowdetail, "After running")
### RE-CREATE, RESUME, RUN #################################### ### RE-CREATE, RESUME, RUN ####################################
print("\nResuming and running again:") print_wrapped("Resuming and running again")
# reload flowdetail from backend
# NOTE(harlowja): reload the flow detail from backend, this will allow us to
# resume the flow from its suspended state, but first we need to search for
# the right flow details in the correct logbook where things are stored.
#
# We could avoid re-loading the engine and just do engine.run() again, but this
# example shows how another process may unsuspend a given flow and start it
# again for situations where this is useful to-do (say the process running
# the above flow crashes).
flowdetail2 = find_flow_detail(backend, logbook.uuid, flowdetail2 = find_flow_detail(backend, logbook.uuid,
flowdetail.uuid) flowdetail.uuid)
engine2 = taskflow.engines.load(flow_factory(), engine2 = taskflow.engines.load(flow_factory(),
flow_detail=flowdetail, flow_detail=flowdetail,
backend=backend) backend=backend)
engine2.run() engine2.run()
print_task_states(flowdetail, "\nAt the end:") print_task_states(flowdetail, "At the end")