7038758960
Add a new parameter to Scheduler to allow it to use spawn multiprocessing method. This is only available with python3 therefore the parameter is ignored with python2.
1795 lines
68 KiB
Python
1795 lines
68 KiB
Python
#!/usr/bin/env python
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# -*- coding: utf-8 -*-
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# vim: set ts=4 sw=4 et ai:
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"""
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| This file is part of the web2py Web Framework
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| Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu>
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| License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html)
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Background processes made simple
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---------------------------------
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"""
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from __future__ import print_function
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import socket
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import os
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import logging
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import types
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from functools import reduce
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import datetime
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import re
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import sys
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from json import loads, dumps
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import tempfile
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import traceback
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import threading
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import multiprocessing
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import time
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import signal
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from gluon import DAL, Field, IS_NOT_EMPTY, IS_IN_SET, IS_NOT_IN_DB, IS_EMPTY_OR
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from gluon import IS_INT_IN_RANGE, IS_DATETIME, IS_IN_DB
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from gluon.utils import web2py_uuid
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from gluon._compat import Queue, long, iteritems, PY2, to_bytes, string_types, integer_types
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from gluon.storage import Storage
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USAGE = """
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## Example
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For any existing application myapp
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Create File: myapp/models/scheduler.py ======
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from gluon.scheduler import Scheduler
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def demo1(*args, **vars):
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print('you passed args=%s and vars=%s' % (args, vars))
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return 'done!'
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def demo2():
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1/0
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scheduler = Scheduler(db, dict(demo1=demo1, demo2=demo2))
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## run worker nodes with:
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cd web2py
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python web2py.py -K myapp
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or
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python gluon/scheduler.py -u sqlite://storage.sqlite \
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-f applications/myapp/databases/ \
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-t mytasks.py
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(-h for info)
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python scheduler.py -h
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## schedule jobs using
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http://127.0.0.1:8000/myapp/appadmin/insert/db/scheduler_task
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## monitor scheduled jobs
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http://127.0.0.1:8000/myapp/appadmin/select/db?query=db.scheduler_task.id
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## view completed jobs
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http://127.0.0.1:8000/myapp/appadmin/select/db?query=db.scheduler_run.id
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## view workers
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http://127.0.0.1:8000/myapp/appadmin/select/db?query=db.scheduler_worker.id
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"""
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IDENTIFIER = "%s#%s" % (socket.gethostname(), os.getpid())
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logger = logging.getLogger('web2py.scheduler.%s' % IDENTIFIER)
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QUEUED = 'QUEUED'
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ASSIGNED = 'ASSIGNED'
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RUNNING = 'RUNNING'
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COMPLETED = 'COMPLETED'
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FAILED = 'FAILED'
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TIMEOUT = 'TIMEOUT'
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STOPPED = 'STOPPED'
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ACTIVE = 'ACTIVE'
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TERMINATE = 'TERMINATE'
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DISABLED = 'DISABLED'
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KILL = 'KILL'
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PICK = 'PICK'
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STOP_TASK = 'STOP_TASK'
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EXPIRED = 'EXPIRED'
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SECONDS = 1
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HEARTBEAT = 3 * SECONDS
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MAXHIBERNATION = 10
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CLEAROUT = '!clear!'
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RESULTINFILE = 'result_in_file:'
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CALLABLETYPES = (types.LambdaType, types.FunctionType,
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types.BuiltinFunctionType,
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types.MethodType, types.BuiltinMethodType)
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class Task(object):
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"""Defines a "task" object that gets passed from the main thread to the
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executor's one
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"""
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def __init__(self, app, function, timeout, args='[]', vars='{}', **kwargs):
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logger.debug(' new task allocated: %s.%s', app, function)
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self.app = app
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self.function = function
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self.timeout = timeout
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self.args = args # json
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self.vars = vars # json
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self.__dict__.update(kwargs)
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def __str__(self):
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return '<Task: %s>' % self.function
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class TaskReport(object):
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"""Defines a "task report" object that gets passed from the executor's
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thread to the main one
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"""
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def __init__(self, status, result=None, output=None, tb=None):
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logger.debug(' new task report: %s', status)
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if tb:
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logger.debug(' traceback: %s', tb)
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else:
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logger.debug(' result: %s', result)
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self.status = status
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self.result = result
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self.output = output
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self.tb = tb
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def __str__(self):
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return '<TaskReport: %s>' % self.status
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class JobGraph(object):
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"""Experimental: dependencies amongs tasks."""
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def __init__(self, db, job_name):
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self.job_name = job_name or 'job_0'
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self.db = db
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def add_deps(self, task_parent, task_child):
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"""Create a dependency between task_parent and task_child."""
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self.db.scheduler_task_deps.insert(task_parent=task_parent,
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task_child=task_child,
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job_name=self.job_name)
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def validate(self, job_name=None):
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"""Validate if all tasks job_name can be completed.
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Checks if there are no mutual dependencies among tasks.
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Commits at the end if successfull, or it rollbacks the entire
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transaction. Handle with care!
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"""
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db = self.db
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sd = db.scheduler_task_deps
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if job_name:
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q = sd.job_name == job_name
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else:
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q = sd.id
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edges = db(q).select()
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nested_dict = {}
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for row in edges:
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k = row.task_parent
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if k in nested_dict:
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nested_dict[k].add(row.task_child)
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else:
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nested_dict[k] = set((row.task_child,))
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try:
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rtn = []
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for k, v in nested_dict.items():
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v.discard(k) # Ignore self dependencies
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extra_items_in_deps = reduce(set.union, nested_dict.values()) - set(nested_dict.keys())
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nested_dict.update(dict((item, set()) for item in extra_items_in_deps))
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while True:
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ordered = set(item for item, dep in nested_dict.items() if not dep)
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if not ordered:
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break
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rtn.append(ordered)
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nested_dict = dict(
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(item, (dep - ordered)) for item, dep in nested_dict.items()
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if item not in ordered
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)
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assert not nested_dict, "A cyclic dependency exists amongst %r" % nested_dict
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db.commit()
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return rtn
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except Exception:
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db.rollback()
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return None
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class CronParser(object):
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def __init__(self, cronline, base=None):
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self.cronline = cronline
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self.sched = base or datetime.datetime.now()
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self.task = None
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@staticmethod
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def _rangetolist(s, period='min'):
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if s.startswith('*'):
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if period == 'min':
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s = s.replace('*', '0-59', 1)
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elif period == 'hr':
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s = s.replace('*', '0-23', 1)
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elif period == 'dom':
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s = s.replace('*', '1-31', 1)
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elif period == 'mon':
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s = s.replace('*', '1-12', 1)
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elif period == 'dow':
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s = s.replace('*', '0-6', 1)
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match = re.match(r'(\d+)-(\d+)/(\d+)', s)
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if match:
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max_ = int(match.group(2)) + 1
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step_ = int(match.group(3))
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else:
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match = re.match(r'(\d+)/(\d+)', s)
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if match:
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ranges_max = dict(min=59, hr=23, mon=12, dom=31, dow=7)
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max_ = ranges_max[period] + 1
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step_ = int(match.group(2))
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if match:
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min_ = int(match.group(1))
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retval = list(range(min_, max_, step_))
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else:
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retval = []
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return retval
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@staticmethod
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def _sanitycheck(values, period):
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if period == 'min':
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check = all(0 <= i <= 59 for i in values)
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elif period == 'hr':
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check = all(0 <= i <= 23 for i in values)
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elif period == 'dom':
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domrange = list(range(1, 32)) + ['l']
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check = all(i in domrange for i in values)
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elif period == 'mon':
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check = all(1 <= i <= 12 for i in values)
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elif period == 'dow':
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check = all(0 <= i <= 7 for i in values)
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return check
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def _parse(self):
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line = self.cronline.lower()
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task = {}
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if line.startswith('@yearly'):
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line = line.replace('@yearly', '0 0 1 1 *')
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elif line.startswith('@annually'):
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line = line.replace('@annually', '0 0 1 1 *')
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elif line.startswith('@monthly'):
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line = line.replace('@monthly', '0 0 1 * *')
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elif line.startswith('@weekly'):
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line = line.replace('@weekly', '0 0 * * 0')
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elif line.startswith('@daily'):
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line = line.replace('@daily', '0 0 * * *')
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elif line.startswith('@midnight'):
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line = line.replace('@midnight', '0 0 * * *')
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elif line.startswith('@hourly'):
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line = line.replace('@hourly', '0 * * * *')
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params = line.strip().split()
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if len(params) < 5:
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raise ValueError('Invalid cron line (too short)')
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elif len(params) > 5:
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raise ValueError('Invalid cron line (too long)')
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daysofweek = {'sun': 0, 'mon': 1, 'tue': 2, 'wed': 3, 'thu': 4,
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'fri': 5, 'sat': 6}
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monthsofyear = {'jan': 1, 'feb': 2, 'mar': 3, 'apr': 4, 'may': 5,
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'jun': 6, 'jul': 7, 'aug': 8, 'sep': 9, 'oct': 10,
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'nov': 11, 'dec': 12}
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for (s, i) in zip(params, ('min', 'hr', 'dom', 'mon', 'dow')):
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if s != '*':
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task[i] = []
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vals = s.split(',')
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for val in vals:
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if i == 'dow':
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refdict = daysofweek
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elif i == 'mon':
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refdict = monthsofyear
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if i in ('dow', 'mon') and '-' in val and '/' not in val:
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isnum = val.split('-')[0].isdigit()
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if isnum:
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val = '%s/1' % val
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else:
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val = '-'.join([str(refdict.get(v, ''))
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for v in val.split('-')])
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if '-' in val and '/' not in val:
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val = '%s/1' % val
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if '/' in val:
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task[i] += self._rangetolist(val, i)
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elif val.isdigit():
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task[i].append(int(val))
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elif i in ('dow', 'mon'):
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if val in refdict:
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task[i].append(refdict[val])
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elif i == 'dom' and val == 'l':
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task[i].append(val)
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if not task[i]:
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raise ValueError('Invalid cron value (%s)' % s)
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if not self._sanitycheck(task[i], i):
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raise ValueError('Invalid cron value (%s)' % s)
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task[i] = sorted(task[i])
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self.task = task
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@staticmethod
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def _get_next_dow(sched, task):
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task_dow = [a % 7 for a in task['dow']]
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while sched.isoweekday() % 7 not in task_dow:
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sched += datetime.timedelta(days=1)
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return sched
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@staticmethod
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def _get_next_dom(sched, task):
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if task['dom'] == ['l']:
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# instead of calendar.isleap
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try:
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last_feb = 29
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datetime.date(sched.year, 2, last_feb)
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except ValueError:
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last_feb = 28
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lastdayofmonth = [
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31, last_feb, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
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]
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task_dom = [lastdayofmonth[sched.month - 1]]
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else:
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task_dom = task['dom']
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while sched.day not in task_dom:
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sched += datetime.timedelta(days=1)
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return sched
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@staticmethod
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def _get_next_mon(sched, task):
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while sched.month not in task['mon']:
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if sched.month < 12:
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sched = sched.replace(month=sched.month + 1)
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else:
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sched = sched.replace(month=1, year=sched.year + 1)
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return sched
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@staticmethod
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def _getnext_hhmm(sched, task, add_to=True):
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if add_to:
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sched += datetime.timedelta(minutes=1)
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if 'min' in task:
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while sched.minute not in task['min']:
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sched += datetime.timedelta(minutes=1)
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if 'hr' in task and sched.hour not in task['hr']:
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while sched.hour not in task['hr']:
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sched += datetime.timedelta(hours=1)
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return sched
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def _getnext_date(self, sched, task):
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if 'dow' in task and 'dom' in task:
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dow = self._get_next_dow(sched, task)
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dom = self._get_next_dom(sched, task)
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sched = min(dow, dom)
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elif 'dow' in task:
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sched = self._get_next_dow(sched, task)
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elif 'dom' in task:
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sched = self._get_next_dom(sched, task)
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if 'mon' in task:
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sched = self._get_next_mon(sched, task)
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return sched.replace(hour=0, minute=0)
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def next(self):
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"""Get next date according to specs."""
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if not self.task:
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self._parse()
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task = self.task
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sched = self.sched
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x = 0
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while x < 1000: # avoid potential max recursions
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x += 1
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try:
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next_date = self._getnext_date(sched, task)
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except (ValueError, OverflowError) as e:
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raise ValueError('Invalid cron expression (%s)' % e)
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if next_date.date() > self.sched.date():
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# we rolled date, check for valid hhmm
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sched = self._getnext_hhmm(next_date, task, False)
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break
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else:
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# same date, get next hhmm
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sched_time = self._getnext_hhmm(sched, task, True)
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if sched_time.date() > sched.date():
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# we rolled date again :(
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sched = sched_time
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else:
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sched = sched_time
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break
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else:
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raise ValueError('Potential bug found, please submit your '
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'cron expression to the authors')
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self.sched = sched
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return sched
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def __iter__(self):
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"""Support iteration."""
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return self
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__next__ = next
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# the two functions below deal with simplejson decoding as unicode,
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# esp for the dict decode and subsequent usage as function Keyword arguments
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# unicode variable names won't work!
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# borrowed from http://stackoverflow.com/questions/956867/
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def _decode_list(lst):
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if not PY2:
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return lst
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newlist = []
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for i in lst:
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if isinstance(i, string_types):
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i = to_bytes(i)
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elif isinstance(i, list):
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i = _decode_list(i)
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newlist.append(i)
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return newlist
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def _decode_dict(dct):
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if not PY2:
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return dct
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newdict = {}
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for k, v in iteritems(dct):
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k = to_bytes(k)
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if isinstance(v, string_types):
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v = to_bytes(v)
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elif isinstance(v, list):
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v = _decode_list(v)
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newdict[k] = v
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return newdict
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def executor(retq, task, outq):
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"""The function used to execute tasks in the background process."""
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logger.debug(' task started')
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class LogOutput(object):
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"""Facility to log output at intervals."""
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def __init__(self, out_queue):
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self.out_queue = out_queue
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self.stdout = sys.stdout
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self.written = False
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sys.stdout = self
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def close(self):
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sys.stdout = self.stdout
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if self.written:
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# see "Joining processes that use queues" section in
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# https://docs.python.org/2/library/multiprocessing.html#programming-guidelines
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# https://docs.python.org/3/library/multiprocessing.html#programming-guidelines
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self.out_queue.cancel_join_thread()
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def flush(self):
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pass
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def write(self, data):
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self.out_queue.put(data)
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self.written = True
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W2P_TASK = Storage({
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'id': task.task_id,
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'uuid': task.uuid,
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'run_id': task.run_id
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})
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stdout = LogOutput(outq)
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try:
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if task.app:
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from gluon.shell import env, parse_path_info
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from gluon import current
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## FIXME: why temporarily change the log level of the root logger?
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#level = logging.getLogger().getEffectiveLevel()
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#logging.getLogger().setLevel(logging.WARN)
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# support for task.app like 'app/controller'
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(a, c, f) = parse_path_info(task.app)
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_env = env(a=a, c=c, import_models=True,
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extra_request={'is_scheduler': True})
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#logging.getLogger().setLevel(level)
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f = task.function
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functions = current._scheduler.tasks
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if functions:
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_function = functions.get(f)
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else:
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# look into env
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_function = _env.get(f)
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if not isinstance(_function, CALLABLETYPES):
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raise NameError(
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"name '%s' not found in scheduler's environment" % f)
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# Inject W2P_TASK into environment
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_env.update({'W2P_TASK': W2P_TASK})
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# Inject W2P_TASK into current
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current.W2P_TASK = W2P_TASK
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globals().update(_env)
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args = _decode_list(loads(task.args))
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vars = loads(task.vars, object_hook=_decode_dict)
|
|
result = dumps(_function(*args, **vars))
|
|
else:
|
|
# for testing purpose only
|
|
result = eval(task.function)(
|
|
*loads(task.args, object_hook=_decode_dict),
|
|
**loads(task.vars, object_hook=_decode_dict))
|
|
if len(result) >= 1024:
|
|
fd, temp_path = tempfile.mkstemp(suffix='.w2p_sched')
|
|
with os.fdopen(fd, 'w') as f:
|
|
f.write(result)
|
|
result = RESULTINFILE + temp_path
|
|
retq.put(TaskReport('COMPLETED', result=result))
|
|
except:
|
|
tb = traceback.format_exc()
|
|
retq.put(TaskReport('FAILED', tb=tb))
|
|
finally:
|
|
stdout.close()
|
|
|
|
|
|
class IS_CRONLINE(object):
|
|
"""
|
|
Validates cronline
|
|
"""
|
|
def __init__(self, error_message=None):
|
|
self.error_message = error_message
|
|
|
|
def __call__(self, value, record_id=None):
|
|
recur = CronParser(value, datetime.datetime.now())
|
|
try:
|
|
recur.next()
|
|
return (value, None)
|
|
except ValueError as e:
|
|
if not self.error_message:
|
|
return (value, e)
|
|
return (value, self.error_message)
|
|
|
|
class TYPE(object):
|
|
"""
|
|
Validator that checks whether field is valid json and validates its type.
|
|
Used for `args` and `vars` of the scheduler_task table
|
|
"""
|
|
|
|
def __init__(self, myclass=list, parse=False):
|
|
self.myclass = myclass
|
|
self.parse = parse
|
|
|
|
def __call__(self, value, record_id=None):
|
|
from gluon import current
|
|
try:
|
|
obj = loads(value)
|
|
except:
|
|
return (value, current.T('invalid json'))
|
|
else:
|
|
if isinstance(obj, self.myclass):
|
|
if self.parse:
|
|
return (obj, None)
|
|
else:
|
|
return (value, None)
|
|
else:
|
|
return (value, current.T('Not of type: %s') % self.myclass)
|
|
|
|
|
|
TASK_STATUS = (QUEUED, RUNNING, COMPLETED, FAILED, TIMEOUT, STOPPED, EXPIRED)
|
|
RUN_STATUS = (RUNNING, COMPLETED, FAILED, TIMEOUT, STOPPED)
|
|
WORKER_STATUS = (ACTIVE, PICK, DISABLED, TERMINATE, KILL, STOP_TASK)
|
|
|
|
|
|
class Scheduler(threading.Thread):
|
|
"""Scheduler object
|
|
|
|
Args:
|
|
db: DAL connection where Scheduler will create its tables
|
|
tasks(dict): either a dict containing name-->func or None.
|
|
If None, functions will be searched in the environment
|
|
migrate(bool): turn migration on/off for the Scheduler's tables
|
|
worker_name(str): force worker_name to identify each process.
|
|
Leave it to None to autoassign a name (hostname#pid)
|
|
group_names(list): process tasks belonging to this group
|
|
defaults to ['main'] if nothing gets passed
|
|
heartbeat(int): how many seconds the worker sleeps between one
|
|
execution and the following one. Indirectly sets how many seconds
|
|
will pass between checks for new tasks
|
|
max_empty_runs(int): how many loops are allowed to pass without
|
|
processing any tasks before exiting the process. 0 to keep always
|
|
the process alive
|
|
discard_results(bool): Scheduler stores executions's details into the
|
|
scheduler_run table. By default, only if there is a result the
|
|
details are kept. Turning this to True means discarding results
|
|
even for tasks that return something
|
|
utc_time(bool): do all datetime calculations assuming UTC as the
|
|
timezone. Remember to pass `start_time` and `stop_time` to tasks
|
|
accordingly
|
|
use_spawn(bool): use spawn for subprocess (only useable with python3)
|
|
"""
|
|
|
|
def __init__(self, db, tasks=None, migrate=True,
|
|
worker_name=None, group_names=None, heartbeat=HEARTBEAT,
|
|
max_empty_runs=0, discard_results=False, utc_time=False, use_spawn=False):
|
|
|
|
threading.Thread.__init__(self)
|
|
self.setDaemon(True)
|
|
self.process = None # the background process
|
|
self.process_queues = (None, None)
|
|
self.have_heartbeat = True # set to False to kill
|
|
self.empty_runs = 0
|
|
|
|
self.db = db
|
|
self.db_thread = None
|
|
self.tasks = tasks
|
|
self.group_names = group_names or ['main']
|
|
self.heartbeat = heartbeat
|
|
self.worker_name = worker_name or IDENTIFIER
|
|
self.max_empty_runs = max_empty_runs
|
|
self.discard_results = discard_results
|
|
self.is_a_ticker = False
|
|
self.do_assign_tasks = False
|
|
self.greedy = False
|
|
self.utc_time = utc_time
|
|
self.w_stats_lock = threading.RLock()
|
|
self.w_stats = Storage(
|
|
dict(
|
|
status=RUNNING,
|
|
sleep=heartbeat,
|
|
total=0,
|
|
errors=0,
|
|
empty_runs=0,
|
|
queue=0,
|
|
distribution=None,
|
|
workers=0)
|
|
) # dict holding statistics
|
|
|
|
from gluon import current
|
|
current._scheduler = self
|
|
|
|
self.define_tables(db, migrate=migrate)
|
|
self.use_spawn = use_spawn
|
|
|
|
def execute(self, task):
|
|
"""Start the background process.
|
|
|
|
Args:
|
|
task : a `Task` object
|
|
|
|
Returns:
|
|
a `TaskReport` object
|
|
"""
|
|
outq = None
|
|
retq = None
|
|
if (self.use_spawn and not PY2):
|
|
ctx = multiprocessing.get_context('spawn')
|
|
outq = ctx.Queue()
|
|
retq = ctx.Queue(maxsize=1)
|
|
sel.process = p = ctx.Process(target=executor, args=(retq, task, outq))
|
|
else:
|
|
outq = multiprocessing.Queue()
|
|
retq = multiprocessing.Queue(maxsize=1)
|
|
self.process = p = \
|
|
multiprocessing.Process(target=executor, args=(retq, task, outq))
|
|
|
|
self.process_queues = (retq, outq)
|
|
|
|
logger.debug(' task starting')
|
|
p.start()
|
|
start = time.time()
|
|
|
|
if task.sync_output > 0:
|
|
run_timeout = task.sync_output
|
|
else:
|
|
run_timeout = task.timeout
|
|
task_output = tout = ''
|
|
try:
|
|
while p.is_alive() and (not task.timeout or
|
|
time.time() - start < task.timeout):
|
|
# NOTE: try always to empty the out queue before
|
|
# the child process is joined,
|
|
# see "Joining processes that use queues" section in
|
|
# https://docs.python.org/2/library/multiprocessing.html#programming-guidelines
|
|
# https://docs.python.org/3/library/multiprocessing.html#programming-guidelines
|
|
while True:
|
|
try:
|
|
tout += outq.get(timeout=2)
|
|
except Queue.Empty:
|
|
break
|
|
if tout:
|
|
logger.debug(' partial output: "%s"', tout)
|
|
if CLEAROUT in tout:
|
|
task_output = tout[
|
|
tout.rfind(CLEAROUT) + len(CLEAROUT):]
|
|
else:
|
|
task_output += tout
|
|
try:
|
|
db = self.db
|
|
db(db.scheduler_run.id == task.run_id).update(run_output=task_output)
|
|
db.commit()
|
|
tout = ''
|
|
logger.debug(' partial output saved')
|
|
except Exception:
|
|
logger.exception(' error while saving partial output')
|
|
task_output = task_output[:-len(tout)]
|
|
p.join(timeout=run_timeout)
|
|
except:
|
|
logger.exception(' task stopped by general exception')
|
|
self.terminate_process()
|
|
tr = TaskReport(STOPPED)
|
|
else:
|
|
if p.is_alive():
|
|
logger.debug(' task timeout')
|
|
self.terminate_process(flush_ret=False)
|
|
try:
|
|
# we try to get a traceback here
|
|
tr = retq.get(timeout=2) # NOTE: risky after terminate
|
|
tr.status = TIMEOUT
|
|
tr.output = task_output
|
|
except Queue.Empty:
|
|
tr = TaskReport(TIMEOUT)
|
|
else:
|
|
try:
|
|
tr = retq.get_nowait()
|
|
except Queue.Empty:
|
|
logger.debug(' task stopped')
|
|
tr = TaskReport(STOPPED)
|
|
else:
|
|
logger.debug(' task completed or failed')
|
|
result = tr.result
|
|
if result and result.startswith(RESULTINFILE):
|
|
temp_path = result.replace(RESULTINFILE, '', 1)
|
|
with open(temp_path) as f:
|
|
tr.result = f.read()
|
|
os.unlink(temp_path)
|
|
tr.output = task_output
|
|
return tr
|
|
|
|
_terminate_process_lock = threading.RLock()
|
|
|
|
def terminate_process(self, flush_out=True, flush_ret=True):
|
|
"""Terminate any running tasks (internal use only)"""
|
|
if self.process is not None:
|
|
# must synchronize since we are called by main and heartbeat thread
|
|
with self._terminate_process_lock:
|
|
if flush_out:
|
|
queue = self.process_queues[1]
|
|
while not queue.empty(): # NOTE: empty() is not reliable
|
|
try:
|
|
queue.get_nowait()
|
|
except Queue.Empty:
|
|
pass
|
|
if flush_ret:
|
|
queue = self.process_queues[0]
|
|
while not queue.empty():
|
|
try:
|
|
queue.get_nowait()
|
|
except Queue.Empty:
|
|
pass
|
|
logger.debug('terminating process')
|
|
try:
|
|
# NOTE: terminate should not be called when using shared
|
|
# resources, see "Avoid terminating processes"
|
|
# section in
|
|
# https://docs.python.org/2/library/multiprocessing.html#programming-guidelines
|
|
# https://docs.python.org/3/library/multiprocessing.html#programming-guidelines
|
|
self.process.terminate()
|
|
# NOTE: calling join after a terminate is risky,
|
|
# as explained in "Avoid terminating processes"
|
|
# section this can lead to a deadlock
|
|
self.process.join()
|
|
finally:
|
|
self.process = None
|
|
|
|
def die(self):
|
|
"""Forces termination of the worker process along with any running
|
|
task"""
|
|
logger.info('die!')
|
|
self.have_heartbeat = False
|
|
self.terminate_process()
|
|
|
|
def give_up(self):
|
|
"""Waits for any running task to be executed, then exits the worker
|
|
process"""
|
|
logger.info('Giving up as soon as possible!')
|
|
self.have_heartbeat = False
|
|
|
|
def run(self):
|
|
"""This is executed by the heartbeat thread"""
|
|
counter = 0
|
|
while self.have_heartbeat:
|
|
self.send_heartbeat(counter)
|
|
counter += 1
|
|
|
|
def start_heartbeats(self):
|
|
self.start()
|
|
|
|
def __get_migrate(self, tablename, migrate=True):
|
|
if migrate is False:
|
|
return False
|
|
elif migrate is True:
|
|
return True
|
|
elif isinstance(migrate, str):
|
|
return "%s%s.table" % (migrate, tablename)
|
|
return True
|
|
|
|
def now(self):
|
|
"""Shortcut that fetches current time based on UTC preferences."""
|
|
return self.utc_time and datetime.datetime.utcnow() or datetime.datetime.now()
|
|
|
|
def set_requirements(self, scheduler_task):
|
|
"""Called to set defaults for lazy_tables connections."""
|
|
from gluon import current
|
|
if hasattr(current, 'request'):
|
|
scheduler_task.application_name.default = '%s/%s' % (
|
|
current.request.application, current.request.controller
|
|
)
|
|
|
|
def define_tables(self, db, migrate):
|
|
"""Define Scheduler tables structure."""
|
|
from pydal.base import DEFAULT
|
|
logger.debug('defining tables (migrate=%s)', migrate)
|
|
now = self.now
|
|
db.define_table(
|
|
'scheduler_task',
|
|
Field('application_name', requires=IS_NOT_EMPTY(),
|
|
default=None, writable=False),
|
|
Field('task_name', default=None),
|
|
Field('group_name', default='main'),
|
|
Field('status', requires=IS_IN_SET(TASK_STATUS),
|
|
default=QUEUED, writable=False),
|
|
Field('broadcast', 'boolean', default=False),
|
|
Field('function_name',
|
|
requires=IS_IN_SET(sorted(self.tasks.keys()))
|
|
if self.tasks else DEFAULT),
|
|
Field('uuid', length=255,
|
|
requires=IS_NOT_IN_DB(db, 'scheduler_task.uuid'),
|
|
unique=True, default=web2py_uuid),
|
|
Field('args', 'text', default='[]', requires=TYPE(list)),
|
|
Field('vars', 'text', default='{}', requires=TYPE(dict)),
|
|
Field('enabled', 'boolean', default=True),
|
|
Field('start_time', 'datetime', default=now,
|
|
requires=IS_DATETIME()),
|
|
Field('next_run_time', 'datetime', default=now),
|
|
Field('stop_time', 'datetime'),
|
|
Field('repeats', 'integer', default=1, comment="0=unlimited",
|
|
requires=IS_INT_IN_RANGE(0, None)),
|
|
Field('retry_failed', 'integer', default=0, comment="-1=unlimited",
|
|
requires=IS_INT_IN_RANGE(-1, None)),
|
|
Field('period', 'integer', default=60, comment='seconds',
|
|
requires=IS_INT_IN_RANGE(0, None)),
|
|
Field('prevent_drift', 'boolean', default=False,
|
|
comment='Exact start_times between runs'),
|
|
Field('cronline', default=None,
|
|
comment='Discard "period", use this cron expr instead',
|
|
requires=IS_EMPTY_OR(IS_CRONLINE())),
|
|
Field('timeout', 'integer', default=60, comment='seconds',
|
|
requires=IS_INT_IN_RANGE(1, None)),
|
|
Field('sync_output', 'integer', default=0,
|
|
comment="update output every n sec: 0=never",
|
|
requires=IS_INT_IN_RANGE(0, None)),
|
|
Field('times_run', 'integer', default=0, writable=False),
|
|
Field('times_failed', 'integer', default=0, writable=False),
|
|
Field('last_run_time', 'datetime', writable=False, readable=False),
|
|
Field('assigned_worker_name', default='', writable=False),
|
|
on_define=self.set_requirements,
|
|
migrate=self.__get_migrate('scheduler_task', migrate),
|
|
format='(%(id)s) %(task_name)s')
|
|
|
|
db.define_table(
|
|
'scheduler_run',
|
|
Field('task_id', 'reference scheduler_task'),
|
|
Field('status', requires=IS_IN_SET(RUN_STATUS)),
|
|
Field('start_time', 'datetime'),
|
|
Field('stop_time', 'datetime'),
|
|
Field('run_output', 'text'),
|
|
Field('run_result', 'text'),
|
|
Field('traceback', 'text'),
|
|
Field('worker_name', default=self.worker_name),
|
|
migrate=self.__get_migrate('scheduler_run', migrate)
|
|
)
|
|
|
|
db.define_table(
|
|
'scheduler_worker',
|
|
Field('worker_name', length=255, unique=True),
|
|
Field('first_heartbeat', 'datetime'),
|
|
Field('last_heartbeat', 'datetime'),
|
|
Field('status', requires=IS_IN_SET(WORKER_STATUS)),
|
|
Field('is_ticker', 'boolean', default=False, writable=False),
|
|
Field('group_names', 'list:string', default=self.group_names),
|
|
Field('worker_stats', 'json'),
|
|
migrate=self.__get_migrate('scheduler_worker', migrate)
|
|
)
|
|
|
|
db.define_table(
|
|
'scheduler_task_deps',
|
|
Field('job_name', default='job_0'),
|
|
Field('task_parent', 'integer',
|
|
requires=IS_IN_DB(db, 'scheduler_task.id', '%(task_name)s')
|
|
),
|
|
Field('task_child', 'reference scheduler_task'),
|
|
Field('can_visit', 'boolean', default=False),
|
|
migrate=self.__get_migrate('scheduler_task_deps', migrate)
|
|
)
|
|
|
|
if migrate is not False:
|
|
db.commit()
|
|
|
|
def loop(self, worker_name=None):
|
|
"""Main loop.
|
|
|
|
This works basically as a neverending loop that:
|
|
|
|
- checks if the worker is ready to process tasks (is not DISABLED)
|
|
- pops a task from the queue
|
|
- if there is a task:
|
|
|
|
- spawns the executor background process
|
|
- waits for the process to be finished
|
|
- sleeps `heartbeat` seconds
|
|
- if there is not a task:
|
|
|
|
- checks for max_empty_runs
|
|
- sleeps `heartbeat` seconds
|
|
|
|
"""
|
|
signal.signal(signal.SIGTERM, lambda signum, stack_frame: sys.exit(1))
|
|
try:
|
|
self.start_heartbeats()
|
|
while self.have_heartbeat:
|
|
with self.w_stats_lock:
|
|
is_disabled = self.w_stats.status == DISABLED
|
|
if is_disabled:
|
|
logger.debug('Someone stopped me, sleeping until better'
|
|
' times come (%s)', self.w_stats.sleep)
|
|
self.sleep()
|
|
continue
|
|
logger.debug('looping...')
|
|
if self.is_a_ticker and self.do_assign_tasks:
|
|
# I'm a ticker, and 5 loops passed without
|
|
# reassigning tasks, let's do that
|
|
self.wrapped_assign_tasks()
|
|
task = self.wrapped_pop_task()
|
|
if task:
|
|
with self.w_stats_lock:
|
|
self.w_stats.empty_runs = 0
|
|
self.w_stats.status = RUNNING
|
|
self.w_stats.total += 1
|
|
self.wrapped_report_task(task, self.execute(task))
|
|
with self.w_stats_lock:
|
|
if not self.w_stats.status == DISABLED:
|
|
self.w_stats.status = ACTIVE
|
|
else:
|
|
with self.w_stats_lock:
|
|
self.w_stats.empty_runs += 1
|
|
if self.max_empty_runs != 0:
|
|
logger.debug('empty runs %s/%s',
|
|
self.w_stats.empty_runs,
|
|
self.max_empty_runs)
|
|
if self.w_stats.empty_runs >= self.max_empty_runs:
|
|
logger.info(
|
|
'empty runs limit reached, killing myself')
|
|
self.die()
|
|
if self.is_a_ticker and self.greedy:
|
|
# there could be other tasks ready to be assigned
|
|
logger.info('TICKER: greedy loop')
|
|
self.wrapped_assign_tasks()
|
|
logger.debug('sleeping...')
|
|
self.sleep()
|
|
except (KeyboardInterrupt, SystemExit):
|
|
logger.info('catched')
|
|
self.die()
|
|
|
|
def wrapped_pop_task(self):
|
|
"""Commodity function to call `pop_task` and trap exceptions.
|
|
|
|
If an exception is raised, assume it happened because of database
|
|
contention and retries `pop_task` after 0.5 seconds
|
|
"""
|
|
db = self.db
|
|
db.commit() # for MySQL only; FIXME: Niphlod, still needed? could avoid when not MySQL?
|
|
for x in range(10):
|
|
try:
|
|
return self.pop_task()
|
|
except Exception:
|
|
logger.exception(' error popping tasks')
|
|
self.w_stats.errors += 1
|
|
db.rollback()
|
|
time.sleep(0.5)
|
|
|
|
def pop_task(self):
|
|
"""Grab a task ready to be executed from the queue."""
|
|
now = self.now()
|
|
db = self.db
|
|
st = db.scheduler_task
|
|
grabbed = db(
|
|
(st.assigned_worker_name == self.worker_name) &
|
|
(st.status == ASSIGNED)
|
|
)
|
|
|
|
task = grabbed.select(limitby=(0, 1), orderby=st.next_run_time).first()
|
|
if task:
|
|
# none will touch my task!
|
|
task.update_record(status=RUNNING, last_run_time=now)
|
|
db.commit()
|
|
logger.debug(' work to do %s', task.id)
|
|
else:
|
|
logger.info('nothing to do')
|
|
return None
|
|
|
|
if task.cronline:
|
|
cron_recur = CronParser(task.cronline,
|
|
now.replace(second=0, microsecond=0))
|
|
next_run_time = cron_recur.next()
|
|
elif not task.prevent_drift:
|
|
next_run_time = task.last_run_time + datetime.timedelta(
|
|
seconds=task.period
|
|
)
|
|
else:
|
|
# calc next_run_time based on available slots
|
|
# see #1191
|
|
next_run_time = task.start_time
|
|
secondspassed = (now - next_run_time).total_seconds()
|
|
times = secondspassed // task.period + 1
|
|
next_run_time += datetime.timedelta(seconds=task.period * times)
|
|
|
|
times_run = task.times_run + 1
|
|
if times_run < task.repeats or task.repeats == 0:
|
|
# need to run (repeating task)
|
|
run_again = True
|
|
else:
|
|
# no need to run again
|
|
run_again = False
|
|
run_id = 0
|
|
while not self.discard_results: # FIXME: forever?
|
|
logger.debug(' new scheduler_run record')
|
|
try:
|
|
run_id = db.scheduler_run.insert(
|
|
task_id=task.id,
|
|
status=RUNNING,
|
|
start_time=now,
|
|
worker_name=self.worker_name)
|
|
db.commit()
|
|
break
|
|
except Exception:
|
|
logger.exception(' error inserting scheduler_run')
|
|
db.rollback()
|
|
time.sleep(0.5)
|
|
logger.info('new task %(id)s "%(task_name)s"'
|
|
' %(application_name)s.%(function_name)s' % task)
|
|
return Task(
|
|
app=task.application_name,
|
|
function=task.function_name,
|
|
timeout=task.timeout,
|
|
args=task.args, # in json
|
|
vars=task.vars, # in json
|
|
task_id=task.id,
|
|
run_id=run_id,
|
|
run_again=run_again,
|
|
next_run_time=next_run_time,
|
|
times_run=times_run,
|
|
stop_time=task.stop_time,
|
|
retry_failed=task.retry_failed,
|
|
times_failed=task.times_failed,
|
|
sync_output=task.sync_output,
|
|
uuid=task.uuid)
|
|
|
|
def wrapped_report_task(self, task, task_report):
|
|
"""Commodity function to call `report_task` and trap exceptions.
|
|
|
|
If an exception is raised, assume it happened because of database
|
|
contention and retries `pop_task` after 0.5 seconds
|
|
"""
|
|
db = self.db
|
|
while True: # FIXME: forever?
|
|
try:
|
|
self.report_task(task, task_report)
|
|
db.commit()
|
|
break
|
|
except Exception:
|
|
logger.exception(' error storing result')
|
|
db.rollback()
|
|
time.sleep(0.5)
|
|
|
|
def report_task(self, task, task_report):
|
|
"""Take care of storing the result according to preferences.
|
|
|
|
Deals with logic for repeating tasks.
|
|
"""
|
|
now = self.now()
|
|
db = self.db
|
|
st = db.scheduler_task
|
|
sr = db.scheduler_run
|
|
if not self.discard_results:
|
|
if task_report.result != 'null' or task_report.tb:
|
|
# result is 'null' as a string if task completed
|
|
# if it's stopped it's None as NoneType, so we record
|
|
# the STOPPED "run" anyway
|
|
logger.debug(' recording task report in db (%s)',
|
|
task_report.status)
|
|
db(sr.id == task.run_id).update(
|
|
status=task_report.status,
|
|
stop_time=now,
|
|
run_result=task_report.result,
|
|
run_output=task_report.output,
|
|
traceback=task_report.tb)
|
|
else:
|
|
logger.debug(' deleting task report in db because of no result')
|
|
db(sr.id == task.run_id).delete()
|
|
# if there is a stop_time and the following run would exceed it
|
|
is_expired = (task.stop_time and
|
|
task.next_run_time > task.stop_time or
|
|
False)
|
|
status = (task.run_again and is_expired and EXPIRED or
|
|
task.run_again and not is_expired and QUEUED or
|
|
COMPLETED)
|
|
if task_report.status == COMPLETED:
|
|
d = dict(status=status,
|
|
next_run_time=task.next_run_time,
|
|
times_run=task.times_run,
|
|
times_failed=0
|
|
)
|
|
db(st.id == task.task_id).update(**d)
|
|
if status == COMPLETED:
|
|
self.update_dependencies(task.task_id)
|
|
else:
|
|
st_mapping = {'FAILED': 'FAILED',
|
|
'TIMEOUT': 'TIMEOUT',
|
|
'STOPPED': 'FAILED'}[task_report.status]
|
|
status = (task.retry_failed
|
|
and task.times_failed < task.retry_failed
|
|
and QUEUED or task.retry_failed == -1
|
|
and QUEUED or st_mapping)
|
|
db(st.id == task.task_id).update(
|
|
times_failed=st.times_failed + 1,
|
|
next_run_time=task.next_run_time,
|
|
status=status
|
|
)
|
|
logger.info('task completed (%s)', task_report.status)
|
|
|
|
def update_dependencies(self, task_id):
|
|
"""Unblock execution paths for Jobs."""
|
|
db = self.db
|
|
db(db.scheduler_task_deps.task_child == task_id).update(can_visit=True)
|
|
|
|
def adj_hibernation(self):
|
|
"""Used to increase the "sleep" interval for DISABLED workers."""
|
|
with self.w_stats_lock:
|
|
if self.w_stats.status == DISABLED:
|
|
wk_st = self.w_stats.sleep
|
|
hibernation = wk_st + HEARTBEAT if wk_st < MAXHIBERNATION else MAXHIBERNATION
|
|
self.w_stats.sleep = hibernation
|
|
|
|
def send_heartbeat(self, counter):
|
|
"""Coordination among available workers.
|
|
|
|
It:
|
|
- sends the heartbeat
|
|
- elects a ticker among available workers (the only process that
|
|
effectively dispatch tasks to workers)
|
|
- deals with worker's statuses
|
|
- does "housecleaning" for dead workers
|
|
- triggers tasks assignment to workers
|
|
"""
|
|
if self.db_thread:
|
|
# BKR 20180612 check if connection still works
|
|
try:
|
|
self.db_thread(self.db_thread.scheduler_worker).count()
|
|
except self.db_thread._adapter.connection.OperationalError:
|
|
# if not -> throw away self.db_thread and force reconnect
|
|
self.db_thread = None
|
|
|
|
if not self.db_thread:
|
|
logger.debug('thread building own DAL object')
|
|
self.db_thread = DAL(
|
|
self.db._uri, folder=self.db._adapter.folder, decode_credentials=True)
|
|
self.define_tables(self.db_thread, migrate=False)
|
|
|
|
try:
|
|
now = self.now()
|
|
db = self.db_thread
|
|
sw = db.scheduler_worker
|
|
st = db.scheduler_task
|
|
# record heartbeat
|
|
row = db(sw.worker_name == self.worker_name).select().first()
|
|
with self.w_stats_lock:
|
|
if not row:
|
|
sw.insert(status=ACTIVE, worker_name=self.worker_name,
|
|
first_heartbeat=now, last_heartbeat=now,
|
|
group_names=self.group_names,
|
|
worker_stats=self.w_stats)
|
|
self.w_stats.status = ACTIVE
|
|
self.w_stats.sleep = self.heartbeat
|
|
backed_status = ACTIVE
|
|
else:
|
|
backed_status = row.status
|
|
if backed_status == DISABLED:
|
|
# keep sleeping
|
|
self.w_stats.status = DISABLED
|
|
logger.debug('........recording heartbeat (DISABLED)')
|
|
db(sw.worker_name == self.worker_name).update(
|
|
last_heartbeat=now,
|
|
worker_stats=self.w_stats)
|
|
elif backed_status == TERMINATE:
|
|
self.w_stats.status = TERMINATE
|
|
logger.debug("Waiting to terminate the current task")
|
|
self.give_up()
|
|
elif backed_status == KILL:
|
|
self.w_stats.status = KILL
|
|
self.die()
|
|
return
|
|
else:
|
|
if backed_status == STOP_TASK:
|
|
logger.info('Asked to kill the current task')
|
|
self.terminate_process()
|
|
logger.debug('........recording heartbeat (%s)',
|
|
self.w_stats.status)
|
|
db(sw.worker_name == self.worker_name).update(
|
|
last_heartbeat=now, status=ACTIVE,
|
|
worker_stats=self.w_stats)
|
|
self.w_stats.sleep = self.heartbeat # re-activating the process
|
|
if self.w_stats.status != RUNNING:
|
|
self.w_stats.status = ACTIVE
|
|
|
|
self.do_assign_tasks = False
|
|
if counter % 5 == 0 or backed_status == PICK:
|
|
try:
|
|
# delete dead workers
|
|
expiration = now - datetime.timedelta(
|
|
seconds=self.heartbeat * 3)
|
|
departure = now - datetime.timedelta(
|
|
seconds=self.heartbeat * 3 * 15)
|
|
logger.debug(
|
|
' freeing workers that have not sent heartbeat')
|
|
dead_workers = db(
|
|
((sw.last_heartbeat < expiration) & (sw.status == ACTIVE)) |
|
|
((sw.last_heartbeat < departure) & (sw.status != ACTIVE))
|
|
)
|
|
dead_workers_name = dead_workers._select(sw.worker_name)
|
|
db(
|
|
(st.assigned_worker_name.belongs(dead_workers_name)) &
|
|
(st.status == RUNNING)
|
|
).update(assigned_worker_name='', status=QUEUED)
|
|
dead_workers.delete()
|
|
try:
|
|
self.is_a_ticker = self.being_a_ticker()
|
|
except:
|
|
logger.exception('Error coordinating TICKER')
|
|
with self.w_stats_lock:
|
|
if self.w_stats.status == ACTIVE:
|
|
self.do_assign_tasks = True
|
|
except:
|
|
logger.exception('Error cleaning up')
|
|
|
|
db.commit()
|
|
except:
|
|
logger.exception('Error retrieving status')
|
|
db.rollback()
|
|
self.adj_hibernation()
|
|
self.sleep()
|
|
|
|
def being_a_ticker(self):
|
|
"""Elect a TICKER process that assigns tasks to available workers.
|
|
|
|
Does its best to elect a worker that is not busy processing other tasks
|
|
to allow a proper distribution of tasks among all active workers ASAP
|
|
"""
|
|
db = self.db_thread
|
|
sw = db.scheduler_worker
|
|
my_name = self.worker_name
|
|
all_active = db(
|
|
(sw.worker_name != my_name) & (sw.status == ACTIVE)
|
|
).select(sw.is_ticker, sw.worker_name)
|
|
ticker = all_active.find(lambda row: row.is_ticker is True).first()
|
|
with self.w_stats_lock:
|
|
not_busy = self.w_stats.status == ACTIVE
|
|
if not ticker:
|
|
# if no other tickers are around
|
|
if not_busy:
|
|
# only if I'm not busy
|
|
db(sw.worker_name == my_name).update(is_ticker=True)
|
|
db(sw.worker_name != my_name).update(is_ticker=False)
|
|
logger.info("TICKER: I'm a ticker")
|
|
else:
|
|
# I'm busy
|
|
if len(all_active) >= 1:
|
|
# so I'll "downgrade" myself to a "poor worker"
|
|
db(sw.worker_name == my_name).update(is_ticker=False)
|
|
else:
|
|
not_busy = True
|
|
db.commit()
|
|
return not_busy
|
|
else:
|
|
logger.info(
|
|
"%s is a ticker, I'm a poor worker" % ticker.worker_name)
|
|
return False
|
|
|
|
def wrapped_assign_tasks(self):
|
|
"""Commodity function to call `assign_tasks` and trap exceptions.
|
|
|
|
If an exception is raised, assume it happened because of database
|
|
contention and retries `assign_task` after 0.5 seconds
|
|
"""
|
|
logger.debug('Assigning tasks...')
|
|
db = self.db
|
|
db.commit() # for MySQL only; FIXME: Niphlod, still needed? could avoid when not MySQL?
|
|
for x in range(10):
|
|
try:
|
|
self.assign_tasks()
|
|
db.commit()
|
|
logger.debug('Tasks assigned...')
|
|
break
|
|
except Exception:
|
|
logger.exception('TICKER: error assigning tasks')
|
|
self.w_stats.errors += 1
|
|
db.rollback()
|
|
time.sleep(0.5)
|
|
|
|
def assign_tasks(self):
|
|
"""Assign task to workers, that can then pop them from the queue.
|
|
|
|
Deals with group_name(s) logic, in order to assign linearly tasks
|
|
to available workers for those groups
|
|
"""
|
|
now = self.now()
|
|
db = self.db
|
|
sw = db.scheduler_worker
|
|
st = db.scheduler_task
|
|
sd = db.scheduler_task_deps
|
|
all_workers = db(sw.status == ACTIVE).select()
|
|
# build workers as dict of groups
|
|
wkgroups = {}
|
|
for w in all_workers:
|
|
if w.worker_stats['status'] == 'RUNNING':
|
|
continue
|
|
group_names = w.group_names
|
|
for gname in group_names:
|
|
if gname not in wkgroups:
|
|
wkgroups[gname] = dict(
|
|
workers=[{'name': w.worker_name, 'c': 0}])
|
|
else:
|
|
wkgroups[gname]['workers'].append(
|
|
{'name': w.worker_name, 'c': 0})
|
|
# set queued tasks that expired between "runs" (i.e., you turned off
|
|
# the scheduler): then it wasn't expired, but now it is
|
|
db(
|
|
(st.status.belongs((QUEUED, ASSIGNED))) &
|
|
(st.stop_time < now)
|
|
).update(status=EXPIRED)
|
|
|
|
# calculate dependencies
|
|
deps_with_no_deps = db(
|
|
(sd.can_visit == False) &
|
|
(~sd.task_child.belongs(
|
|
db(sd.can_visit == False)._select(sd.task_parent)
|
|
)
|
|
)
|
|
)._select(sd.task_child)
|
|
no_deps = db(
|
|
(st.status.belongs((QUEUED, ASSIGNED))) &
|
|
(
|
|
(sd.id == None) | (st.id.belongs(deps_with_no_deps))
|
|
)
|
|
)._select(st.id, distinct=True, left=sd.on(
|
|
(st.id == sd.task_parent) &
|
|
(sd.can_visit == False)
|
|
)
|
|
)
|
|
|
|
all_available = db(
|
|
(st.status.belongs((QUEUED, ASSIGNED))) &
|
|
(st.next_run_time <= now) &
|
|
(st.enabled == True) &
|
|
(st.id.belongs(no_deps))
|
|
)
|
|
|
|
limit = len(all_workers) * (50 / (len(wkgroups) or 1))
|
|
# if there are a moltitude of tasks, let's figure out a maximum of
|
|
# tasks per worker. This can be further tuned with some added
|
|
# intelligence (like esteeming how many tasks will a worker complete
|
|
# before the ticker reassign them around, but the gain is quite small
|
|
# 50 is a sweet spot also for fast tasks, with sane heartbeat values
|
|
# NB: ticker reassign tasks every 5 cycles, so if a worker completes
|
|
# its 50 tasks in less than heartbeat*5 seconds,
|
|
# it won't pick new tasks until heartbeat*5 seconds pass.
|
|
|
|
# If a worker is currently elaborating a long task, its tasks needs to
|
|
# be reassigned to other workers
|
|
# this shuffles up things a bit, in order to give a task equal chances
|
|
# to be executed
|
|
|
|
# let's freeze it up
|
|
db.commit()
|
|
tnum = 0
|
|
for group in wkgroups.keys():
|
|
tasks = all_available(st.group_name == group).select(
|
|
limitby=(0, limit), orderby=st.next_run_time)
|
|
# let's break up the queue evenly among workers
|
|
for task in tasks:
|
|
tnum += 1
|
|
gname = task.group_name
|
|
ws = wkgroups.get(gname)
|
|
if ws:
|
|
if task.broadcast:
|
|
for worker in ws['workers']:
|
|
new_task = db.scheduler_task.insert(
|
|
application_name = task.application_name,
|
|
task_name = task.task_name,
|
|
group_name = task.group_name,
|
|
status = ASSIGNED,
|
|
broadcast = False,
|
|
function_name = task.function_name,
|
|
args = task.args,
|
|
start_time = now,
|
|
repeats = 1,
|
|
retry_failed = task.retry_failed,
|
|
sync_output = task.sync_output,
|
|
assigned_worker_name = worker['name'])
|
|
if task.period:
|
|
next_run_time = now+datetime.timedelta(seconds=task.period)
|
|
else:
|
|
# must be cronline
|
|
cron_recur = CronParser(task.cronline,
|
|
now.replace(second=0, microsecond=0))
|
|
next_run_time = cron_recur.next()
|
|
db(st.id == task.id).update(times_run=task.times_run+1,
|
|
next_run_time=next_run_time,
|
|
last_run_time=now)
|
|
db.commit()
|
|
else:
|
|
counter = 0
|
|
myw = 0
|
|
for i, w in enumerate(ws['workers']):
|
|
if w['c'] < counter:
|
|
myw = i
|
|
counter = w['c']
|
|
assigned_wn = wkgroups[gname]['workers'][myw]['name']
|
|
d = dict(
|
|
status=ASSIGNED,
|
|
assigned_worker_name=assigned_wn
|
|
)
|
|
db(
|
|
(st.id == task.id) &
|
|
(st.status.belongs((QUEUED, ASSIGNED)))
|
|
).update(**d)
|
|
wkgroups[gname]['workers'][myw]['c'] += 1
|
|
db.commit()
|
|
# I didn't report tasks but I'm working nonetheless!!!!
|
|
with self.w_stats_lock:
|
|
if tnum > 0:
|
|
self.w_stats.empty_runs = 0
|
|
self.w_stats.queue = tnum
|
|
self.w_stats.distribution = wkgroups
|
|
self.w_stats.workers = len(all_workers)
|
|
# I'll be greedy only if tasks assigned are equal to the limit
|
|
# (meaning there could be others ready to be assigned)
|
|
self.greedy = tnum >= limit
|
|
logger.info('TICKER: workers are %s', len(all_workers))
|
|
logger.info('TICKER: tasks are %s', tnum)
|
|
|
|
def sleep(self):
|
|
"""Calculate the number of seconds to sleep."""
|
|
time.sleep(self.w_stats.sleep)
|
|
# should only sleep until next available task
|
|
|
|
def set_worker_status(self, group_names=None, action=ACTIVE,
|
|
exclude=None, limit=None, worker_name=None):
|
|
"""Internal function to set worker's status."""
|
|
db = self.db
|
|
ws = db.scheduler_worker
|
|
if not group_names:
|
|
group_names = self.group_names
|
|
elif isinstance(group_names, str):
|
|
group_names = [group_names]
|
|
if worker_name:
|
|
db(ws.worker_name == worker_name).update(status=action)
|
|
return
|
|
exclusion = exclude and exclude.append(action) or [action]
|
|
if not limit:
|
|
for group in group_names:
|
|
db(
|
|
(ws.group_names.contains(group)) &
|
|
(~ws.status.belongs(exclusion))
|
|
).update(status=action)
|
|
else:
|
|
for group in group_names:
|
|
workers = db((ws.group_names.contains(group)) &
|
|
(~ws.status.belongs(exclusion))
|
|
)._select(ws.id, limitby=(0, limit))
|
|
db(ws.id.belongs(workers)).update(status=action)
|
|
|
|
def disable(self, group_names=None, limit=None, worker_name=None):
|
|
"""Set DISABLED on the workers processing `group_names` tasks.
|
|
|
|
A DISABLED worker will be kept alive but it won't be able to process
|
|
any waiting tasks, essentially putting it to sleep.
|
|
By default, all group_names of Scheduler's instantation are selected
|
|
"""
|
|
self.set_worker_status(
|
|
group_names=group_names,
|
|
action=DISABLED,
|
|
exclude=[DISABLED, KILL, TERMINATE],
|
|
limit=limit)
|
|
|
|
def resume(self, group_names=None, limit=None, worker_name=None):
|
|
"""Wakes a worker up (it will be able to process queued tasks)"""
|
|
self.set_worker_status(
|
|
group_names=group_names,
|
|
action=ACTIVE,
|
|
exclude=[KILL, TERMINATE],
|
|
limit=limit)
|
|
|
|
def terminate(self, group_names=None, limit=None, worker_name=None):
|
|
"""Sets TERMINATE as worker status. The worker will wait for any
|
|
currently running tasks to be executed and then it will exit gracefully
|
|
"""
|
|
self.set_worker_status(
|
|
group_names=group_names,
|
|
action=TERMINATE,
|
|
exclude=[KILL],
|
|
limit=limit)
|
|
|
|
def kill(self, group_names=None, limit=None, worker_name=None):
|
|
"""Sets KILL as worker status. The worker will be killed even if it's
|
|
processing a task."""
|
|
self.set_worker_status(
|
|
group_names=group_names,
|
|
action=KILL,
|
|
limit=limit)
|
|
|
|
def queue_task(self, function, pargs=[], pvars={}, **kwargs):
|
|
"""
|
|
Queue tasks. This takes care of handling the validation of all
|
|
parameters
|
|
|
|
Args:
|
|
function: the function (anything callable with a __name__)
|
|
pargs: "raw" args to be passed to the function. Automatically
|
|
jsonified.
|
|
pvars: "raw" kwargs to be passed to the function. Automatically
|
|
jsonified
|
|
kwargs: all the parameters available (basically, every
|
|
`scheduler_task` column). If args and vars are here, they
|
|
should be jsonified already, and they will override pargs
|
|
and pvars
|
|
|
|
Returns:
|
|
a dict just as a normal validate_and_insert(), plus a uuid key
|
|
holding the uuid of the queued task. If validation is not passed
|
|
( i.e. some parameters are invalid) both id and uuid will be None,
|
|
and you'll get an "error" dict holding the errors found.
|
|
"""
|
|
if hasattr(function, '__name__'):
|
|
function = function.__name__
|
|
targs = 'args' in kwargs and kwargs.pop('args') or dumps(pargs)
|
|
tvars = 'vars' in kwargs and kwargs.pop('vars') or dumps(pvars)
|
|
tuuid = 'uuid' in kwargs and kwargs.pop('uuid') or web2py_uuid()
|
|
tname = 'task_name' in kwargs and kwargs.pop('task_name') or function
|
|
immediate = 'immediate' in kwargs and kwargs.pop('immediate') or None
|
|
cronline = kwargs.get('cronline')
|
|
kwargs.update(
|
|
function_name=function,
|
|
task_name=tname,
|
|
args=targs,
|
|
vars=tvars,
|
|
uuid=tuuid,
|
|
)
|
|
if cronline:
|
|
try:
|
|
start_time = kwargs.get('start_time', self.now)
|
|
next_run_time = CronParser(cronline, start_time).next()
|
|
kwargs.update(start_time=start_time, next_run_time=next_run_time)
|
|
except Exception:
|
|
pass
|
|
if 'start_time' in kwargs and 'next_run_time' not in kwargs:
|
|
kwargs.update(next_run_time=kwargs['start_time'])
|
|
db = self.db
|
|
rtn = db.scheduler_task.validate_and_insert(**kwargs)
|
|
if not rtn.errors:
|
|
rtn.uuid = tuuid
|
|
if immediate:
|
|
db(
|
|
(db.scheduler_worker.is_ticker == True)
|
|
).update(status=PICK)
|
|
else:
|
|
rtn.uuid = None
|
|
return rtn
|
|
|
|
def task_status(self, ref, output=False):
|
|
"""
|
|
Retrieves task status and optionally the result of the task
|
|
|
|
Args:
|
|
ref: can be
|
|
|
|
- an integer : lookup will be done by scheduler_task.id
|
|
- a string : lookup will be done by scheduler_task.uuid
|
|
- a `Query` : lookup as you wish, e.g. ::
|
|
|
|
db.scheduler_task.task_name == 'test1'
|
|
|
|
output(bool): if `True`, fetch also the scheduler_run record
|
|
|
|
Returns:
|
|
a single Row object, for the last queued task.
|
|
If output == True, returns also the last scheduler_run record.
|
|
The scheduler_run record is fetched by a left join, so it can
|
|
have all fields == None
|
|
|
|
"""
|
|
from pydal.objects import Query
|
|
db = self.db
|
|
sr = db.scheduler_run
|
|
st = db.scheduler_task
|
|
if isinstance(ref, integer_types):
|
|
q = st.id == ref
|
|
elif isinstance(ref, str):
|
|
q = st.uuid == ref
|
|
elif isinstance(ref, Query):
|
|
q = ref
|
|
else:
|
|
raise SyntaxError(
|
|
"You can retrieve results only by id, uuid or Query")
|
|
fields = [st.ALL]
|
|
left = False
|
|
orderby = ~st.id
|
|
if output:
|
|
fields = st.ALL, sr.ALL
|
|
left = sr.on(sr.task_id == st.id)
|
|
orderby = ~st.id | ~sr.id
|
|
row = db(q).select(
|
|
*fields,
|
|
**dict(orderby=orderby,
|
|
left=left,
|
|
limitby=(0, 1))
|
|
).first()
|
|
if row and output:
|
|
row.result = row.scheduler_run.run_result and \
|
|
loads(row.scheduler_run.run_result,
|
|
object_hook=_decode_dict) or None
|
|
return row
|
|
|
|
def stop_task(self, ref):
|
|
"""Shortcut for task termination.
|
|
|
|
If the task is RUNNING it will terminate it, meaning that status
|
|
will be set as FAILED.
|
|
|
|
If the task is QUEUED, its stop_time will be set as to "now",
|
|
the enabled flag will be set to False, and the status to STOPPED
|
|
|
|
Args:
|
|
ref: can be
|
|
|
|
- an integer : lookup will be done by scheduler_task.id
|
|
- a string : lookup will be done by scheduler_task.uuid
|
|
|
|
Returns:
|
|
- 1 if task was stopped (meaning an update has been done)
|
|
- None if task was not found, or if task was not RUNNING or QUEUED
|
|
|
|
Note:
|
|
Experimental
|
|
"""
|
|
db = self.db
|
|
st = db.scheduler_task
|
|
sw = db.scheduler_worker
|
|
if isinstance(ref, integer_types):
|
|
q = st.id == ref
|
|
elif isinstance(ref, str):
|
|
q = st.uuid == ref
|
|
else:
|
|
raise SyntaxError(
|
|
"You can retrieve results only by id or uuid")
|
|
task = db(q).select(st.id, st.status, st.assigned_worker_name)
|
|
task = task.first()
|
|
rtn = None
|
|
if not task:
|
|
return rtn
|
|
if task.status == 'RUNNING':
|
|
q = sw.worker_name == task.assigned_worker_name
|
|
rtn = db(q).update(status=STOP_TASK)
|
|
elif task.status == 'QUEUED':
|
|
rtn = db(q).update(
|
|
stop_time=self.now(),
|
|
enabled=False,
|
|
status=STOPPED)
|
|
return rtn
|
|
|
|
def get_workers(self, only_ticker=False):
|
|
""" Returns a dict holding `worker_name : {**columns}`
|
|
representing all "registered" workers
|
|
only_ticker returns only the workers running as a TICKER,
|
|
if there are any
|
|
"""
|
|
db = self.db
|
|
if only_ticker:
|
|
workers = db(db.scheduler_worker.is_ticker == True).select()
|
|
else:
|
|
workers = db(db.scheduler_worker.id).select()
|
|
all_workers = {}
|
|
for row in workers:
|
|
all_workers[row.worker_name] = Storage(
|
|
status=row.status,
|
|
first_heartbeat=row.first_heartbeat,
|
|
last_heartbeat=row.last_heartbeat,
|
|
group_names=row.group_names,
|
|
is_ticker=row.is_ticker,
|
|
worker_stats=row.worker_stats
|
|
)
|
|
return all_workers
|
|
|
|
|
|
def main():
|
|
"""
|
|
allows to run worker without python web2py.py .... by simply::
|
|
|
|
python gluon/scheduler.py
|
|
|
|
"""
|
|
import optparse
|
|
parser = optparse.OptionParser()
|
|
parser.add_option(
|
|
"-w", "--worker_name", dest="worker_name", default=None,
|
|
help="start a worker with name")
|
|
parser.add_option(
|
|
"-b", "--heartbeat", dest="heartbeat", default=10,
|
|
type='int', help="heartbeat time in seconds (default 10)")
|
|
parser.add_option(
|
|
"-L", "--logger_level", dest="logger_level",
|
|
default=30,
|
|
type='int',
|
|
help="set debug output level (0-100, 0 means all, 100 means none;default is 30)")
|
|
parser.add_option("-E", "--empty-runs",
|
|
dest="max_empty_runs",
|
|
type='int',
|
|
default=0,
|
|
help="max loops with no grabbed tasks permitted (0 for never check)")
|
|
parser.add_option(
|
|
"-g", "--group_names", dest="group_names",
|
|
default='main',
|
|
help="comma separated list of groups to be picked by the worker")
|
|
parser.add_option(
|
|
"-f", "--db_folder", dest="db_folder",
|
|
default='/Users/mdipierro/web2py/applications/scheduler/databases',
|
|
help="location of the dal database folder")
|
|
parser.add_option(
|
|
"-u", "--db_uri", dest="db_uri",
|
|
default='sqlite://storage.sqlite',
|
|
help="database URI string (web2py DAL syntax)")
|
|
parser.add_option(
|
|
"-t", "--tasks", dest="tasks", default=None,
|
|
help="file containing task files, must define" +
|
|
"tasks = {'task_name':(lambda: 'output')} or similar set of tasks")
|
|
parser.add_option(
|
|
"-U", "--utc-time", dest="utc_time", default=False,
|
|
help="work with UTC timestamps"
|
|
)
|
|
(options, args) = parser.parse_args()
|
|
if not options.tasks or not options.db_uri:
|
|
print(USAGE)
|
|
if options.tasks:
|
|
path, filename = os.path.split(options.tasks)
|
|
if filename.endswith('.py'):
|
|
filename = filename[:-3]
|
|
sys.path.append(path)
|
|
print('importing tasks...')
|
|
tasks = __import__(filename, globals(), locals(), [], -1).tasks
|
|
print('tasks found: ' + ', '.join(list(tasks.keys())))
|
|
else:
|
|
tasks = {}
|
|
group_names = [x.strip() for x in options.group_names.split(',')]
|
|
|
|
logging.getLogger().setLevel(options.logger_level)
|
|
|
|
print('groups for this worker: ' + ', '.join(group_names))
|
|
print('connecting to database in folder: ' + options.db_folder or './')
|
|
print('using URI: ' + options.db_uri)
|
|
db = DAL(options.db_uri, folder=options.db_folder, decode_credentials=True)
|
|
print('instantiating scheduler...')
|
|
scheduler = Scheduler(db=db,
|
|
worker_name=options.worker_name,
|
|
tasks=tasks,
|
|
migrate=True,
|
|
group_names=group_names,
|
|
heartbeat=options.heartbeat,
|
|
max_empty_runs=options.max_empty_runs,
|
|
utc_time=options.utc_time)
|
|
signal.signal(signal.SIGTERM, lambda signum, stack_frame: sys.exit(1))
|
|
print('starting main worker loop...')
|
|
scheduler.loop()
|
|
|
|
if __name__ == '__main__':
|
|
main()
|