class TestAutoNow(Model):
create_date = DateTimeProperty(auto_now_add=True)
modified_date = DateTimeProperty(auto_now=True)
class Task(Model):
"""
A scheduled, repeating task that can be executed by any participating servers.
The scheduling is similar to cron jobs. Each task has an hour attribute.
The allowable values for hour are [0-23|*].
To keep the operation reasonably efficient and not cause excessive polling,
the minimum granularity of a Task is hourly. Some examples:
hour='*' - the task would be executed each hour
hour='3' - the task would be executed at 3AM GMT each day.
"""
name = StringProperty()
hour = StringProperty(required=True, validator=check_hour, default='*')
command = StringProperty(required=True)
last_executed = DateTimeProperty()
last_status = IntegerProperty()
last_output = StringProperty()
message_id = StringProperty()
@classmethod
def start_all(cls, queue_name):
for task in cls.all():
task.start(queue_name)
def __init__(self, id=None, **kw):
Model.__init__(self, id, **kw)
self.hourly = self.hour == '*'
self.daily = self.hour != '*'
self.now = datetime.datetime.utcnow()
def check(self):
"""
Determine how long until the next scheduled time for a Task.
Returns the number of seconds until the next scheduled time or zero
if the task needs to be run immediately.
If it's an hourly task and it's never been run, run it now.
If it's a daily task and it's never been run and the hour is right, run it now.
"""
boto.log.info('checking Task[%s]-now=%s, last=%s' %
(self.name, self.now, self.last_executed))
if self.hourly and not self.last_executed:
return 0
if self.daily and not self.last_executed:
if int(self.hour) == self.now.hour:
return 0
else:
return max((int(self.hour) - self.now.hour),
(self.now.hour - int(self.hour))) * 60 * 60
delta = self.now - self.last_executed
if self.hourly:
if delta.seconds >= 60 * 60:
return 0
else:
return 60 * 60 - delta.seconds
else:
if int(self.hour) == self.now.hour:
if delta.days >= 1:
return 0
else:
return 82800 # 23 hours, just to be safe
else:
return max((int(self.hour) - self.now.hour),
(self.now.hour - int(self.hour))) * 60 * 60
def _run(self, msg, vtimeout):
boto.log.info('Task[%s] - running:%s' % (self.name, self.command))
log_fp = StringIO.StringIO()
process = subprocess.Popen(self.command,
shell=True,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
nsecs = 5
current_timeout = vtimeout
while process.poll() == None:
boto.log.info('nsecs=%s, timeout=%s' % (nsecs, current_timeout))
if nsecs >= current_timeout:
current_timeout += vtimeout
boto.log.info('Task[%s] - setting timeout to %d seconds' %
(self.name, current_timeout))
if msg:
msg.change_visibility(current_timeout)
time.sleep(5)
nsecs += 5
t = process.communicate()
log_fp.write(t[0])
log_fp.write(t[1])
boto.log.info('Task[%s] - output: %s' % (self.name, log_fp.getvalue()))
self.last_executed = self.now
self.last_status = process.returncode
self.last_output = log_fp.getvalue()[0:1023]
def run(self, msg, vtimeout=60):
delay = self.check()
boto.log.info('Task[%s] - delay=%s seconds' % (self.name, delay))
if delay == 0:
self._run(msg, vtimeout)
queue = msg.queue
new_msg = queue.new_message(self.id)
new_msg = queue.write(new_msg)
self.message_id = new_msg.id
self.put()
boto.log.info('Task[%s] - new message id=%s' %
(self.name, new_msg.id))
msg.delete()
boto.log.info('Task[%s] - deleted message %s' %
(self.name, msg.id))
else:
boto.log.info('new_vtimeout: %d' % delay)
msg.change_visibility(delay)
def start(self, queue_name):
boto.log.info('Task[%s] - starting with queue: %s' %
(self.name, queue_name))
queue = boto.lookup('sqs', queue_name)
msg = queue.new_message(self.id)
msg = queue.write(msg)
self.message_id = msg.id
self.put()
boto.log.info('Task[%s] - start successful' % self.name)
class TestBasic(Model):
name = StringProperty()
size = IntegerProperty()
foo = BooleanProperty()
date = DateTimeProperty()