def __init__(self, agent_id, node, scheduler_config):
"""Constructor
:param agent_id: The Mesos agent ID for the node
:type agent_id: string
:param node: The node model
:type node: :class:`node.models.Node`
:param scheduler_config: The scheduler configuration
:type scheduler_config: :class:`scheduler.configuration.SchedulerConfiguration`
"""
self._hostname = str(node.hostname) # Never changes
self._id = node.id # Never changes
self._agent_id = agent_id
self._cleanup = NodeCleanup()
self._cleanup_task = None
self._conditions = NodeConditions(self._hostname)
self._health_task = None
self._is_active = node.is_active
self._is_image_pulled = False
self._is_initial_cleanup_completed = False
self._is_online = True
self._is_paused = node.is_paused
self._is_scheduler_paused = scheduler_config.is_paused
self._last_health_task = None
self._last_offer_received = node.last_offer_received
self._lock = threading.Lock()
self._pull_task = None
self._state = None
self._update_state()
def test_handle_regular_cleanup_task(self):
"""Tests handling a regular cleanup task"""
node = Node(self.node_agent, self.node)
node.initial_cleanup_completed()
node_cleanup = NodeCleanup(node)
# No task since there are no job executions to clean
self.assertIsNone(node_cleanup.get_next_task())
# Add job execution and complete task to clean it up
job_exe = RunningJobExecution(self.job_exe)
node_cleanup.add_job_execution(job_exe)
task = node_cleanup.get_next_task()
self.assertIsNotNone(task)
self.assertFalse(task.is_initial_cleanup)
self.assertListEqual(task.job_exes, [job_exe])
task.launch(now())
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.RUNNING, now())
node_cleanup.handle_task_update(update)
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.FINISHED, now())
node_cleanup.handle_task_update(update)
# No task since all job executions have been cleaned
self.assertIsNone(node_cleanup.get_next_task())
def test_paused_node(self):
"""Tests not returning tasks when its node is paused"""
paused_node = node_test_utils.create_node(hostname='host_1', slave_id=self.node_agent)
paused_node.is_paused = True
node = Node(self.node_agent, paused_node)
node_cleanup = NodeCleanup(node)
task = node_cleanup.get_next_task()
# No task due to paused node
self.assertIsNone(task)
def _reset_node(self):
"""Resets the node if it goes away so initial cleanup and the Scale image pull occur when the node comes back.
Caller must have obtained the node's thread lock.
"""
self._cleanup = NodeCleanup()
self._cleanup_task = None
self._health_task = None
self._is_image_pulled = False
self._is_initial_cleanup_completed = False
self._last_health_task = None
self._pull_task = None
def test_handle_killed_task(self):
"""Tests handling killed cleanup task"""
node = Node(self.node_agent, self.node)
node_cleanup = NodeCleanup(node)
# Get initial cleanup task
task = node_cleanup.get_next_task()
task_1_id = task.id
self.assertIsNotNone(task)
# Kill task after running and get different task next time
task.launch(now())
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.RUNNING, now())
node_cleanup.handle_task_update(update)
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.KILLED, now())
node_cleanup.handle_task_update(update)
task = node_cleanup.get_next_task()
self.assertIsNotNone(task)
self.assertNotEqual(task.id, task_1_id)
self.assertFalse(node.is_initial_cleanup_completed)
def test_handle_initial_cleanup_task(self):
"""Tests handling the initial cleanup task"""
node = Node(self.node_agent, self.node)
node_cleanup = NodeCleanup(node)
# Get initial cleanup task
task = node_cleanup.get_next_task()
self.assertIsNotNone(task)
self.assertTrue(task.is_initial_cleanup)
self.assertEqual(task.agent_id, self.node_agent)
# Schedule initial cleanup and make sure no new task is ready
task.launch(now())
self.assertIsNone(node_cleanup.get_next_task())
self.assertFalse(node.is_initial_cleanup_completed)
# Complete initial clean up, verify no new task
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.RUNNING, now())
node_cleanup.handle_task_update(update)
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.FINISHED, now())
node_cleanup.handle_task_update(update)
self.assertIsNone(node_cleanup.get_next_task())
self.assertTrue(node.is_initial_cleanup_completed)
class Node(object):
"""This class represents a node in the scheduler. It combines information retrieved from the database node models as
well as run-time information retrieved from Mesos. This class is thread-safe."""
# Thresholds for when to schedule node tasks again that have failed
CLEANUP_ERR_THRESHOLD = datetime.timedelta(minutes=2)
HEALTH_ERR_THRESHOLD = datetime.timedelta(minutes=2)
IMAGE_PULL_ERR_THRESHOLD = datetime.timedelta(minutes=5)
# Normal health check task threshold
NORMAL_HEALTH_THRESHOLD = datetime.timedelta(minutes=5)
# Node States
deprecated_desc = 'Node is deprecated and will not be used by Scale. Existing jobs on the node will be failed.'
DEPRECATED = NodeState(state='DEPRECATED',
title='Deprecated',
description=deprecated_desc)
OFFLINE = NodeState(
state='OFFLINE',
title='Offline',
description=
'Node is offline/unavailable, so no jobs can currently run on it.')
stopped_desc = 'Scheduler is paused, so no new jobs will be scheduled. Existing jobs will continue to run.'
SCHEDULER_STOPPED = NodeState(state='SCHEDULER_STOPPED',
title='Scheduler Stopped',
description=stopped_desc)
paused_desc = 'Node is paused, so no new jobs will be scheduled. Existing jobs will continue to run.'
PAUSED = NodeState(state='PAUSED', title='Paused', description=paused_desc)
degraded_desc = 'Node has an error condition, putting it in a degraded state.'
degraded_desc += ' New jobs will not be scheduled, and the node will attempt to continue to run existing jobs.'
DEGRADED = NodeState(state='DEGRADED',
title='Degraded',
description=degraded_desc)
cleanup_desc = 'Node is performing an initial cleanup step to remove existing Scale Docker containers and volumes.'
INITIAL_CLEANUP = NodeState(state='INITIAL_CLEANUP',
title='Cleaning up',
description=cleanup_desc)
pull_desc = 'Node is pulling the Scale Docker image.'
IMAGE_PULL = NodeState(state='IMAGE_PULL',
title='Pulling image',
description=pull_desc)
READY = NodeState(state='READY',
title='Ready',
description='Node is ready to run new jobs.')
def __init__(self, agent_id, node, scheduler_config):
"""Constructor
:param agent_id: The Mesos agent ID for the node
:type agent_id: string
:param node: The node model
:type node: :class:`node.models.Node`
:param scheduler_config: The scheduler configuration
:type scheduler_config: :class:`scheduler.configuration.SchedulerConfiguration`
"""
self._hostname = str(node.hostname) # Never changes
self._id = node.id # Never changes
self._agent_id = agent_id
self._cleanup = NodeCleanup()
self._cleanup_task = None
self._conditions = NodeConditions(self._hostname)
self._health_task = None
self._is_active = node.is_active
self._is_image_pulled = False
self._is_initial_cleanup_completed = False
self._is_online = True
self._is_paused = node.is_paused
self._is_scheduler_paused = scheduler_config.is_paused
self._last_health_task = None
self._last_offer_received = node.last_offer_received
self._lock = threading.Lock()
self._pull_task = None
self._state = None
self._update_state()
@property
def agent_id(self):
"""Returns the agent ID of the node
:returns: The agent ID
:rtype: string
"""
return self._agent_id
@property
def hostname(self):
"""Returns the hostname of the node
:returns: The hostname
:rtype: string
"""
return self._hostname
@property
def id(self):
"""Returns the ID of the node
:returns: The node ID
:rtype: int
"""
return self._id
@property
def is_active(self):
"""Indicates whether this node is active (True) or not (False)
:returns: Whether this node is active
:rtype: bool
"""
return self._is_active
def add_job_execution(self, job_exe):
"""Adds a job execution that needs to be cleaned up
:param job_exe: The job execution to add
:type job_exe: :class:`job.execution.job_exe.RunningJobExecution`
"""
with self._lock:
self._cleanup.add_job_execution(job_exe)
self._conditions.update_cleanup_count(
self._cleanup.get_num_job_exes())
def generate_status_json(self, nodes_list):
"""Generates the portion of the status JSON that describes this node
:param nodes_list: The list of nodes within the status JSON
:type nodes_list: :func:`list`
"""
with self._lock:
state_dict = {
'name': self._state.state,
'title': self._state.title,
'description': self._state.description
}
node_dict = {
'id': self._id,
'hostname': self._hostname,
'agent_id': self._agent_id,
'is_active': self._is_active,
'state': state_dict
}
self._conditions.generate_status_json(node_dict)
nodes_list.append(node_dict)
def get_next_tasks(self, when):
"""Returns the next node tasks to launch
:param when: The current time
:type when: :class:`datetime.datetime`
:returns: The list of node tasks to launch
:rtype: [:class:`job.tasks.base_task.Task`]
"""
with self._lock:
self._create_next_tasks(when)
tasks = []
# Check if ready for cleanup task and it hasn't been launched yet
if self._is_ready_for_cleanup_task(when):
if self._cleanup_task and not self._cleanup_task.has_been_launched:
tasks.append(self._cleanup_task)
# Check if ready for health check task and it hasn't been launched yet
if self._is_ready_for_health_task(
when
) and self._health_task and not self._health_task.has_been_launched:
tasks.append(self._health_task)
# Check if ready for pull task and it hasn't been launched yet
if self._is_ready_for_pull_task(
when
) and self._pull_task and not self._pull_task.has_been_launched:
tasks.append(self._pull_task)
return tasks
def handle_task_timeout(self, task):
"""Handles the timeout of the given node task
:param task: The task
:type task: :class:`job.tasks.base_task.Task`
"""
with self._lock:
if self._cleanup_task and self._cleanup_task.id == task.id:
logger.warning('Cleanup task on node %s timed out',
self._hostname)
self._conditions.handle_cleanup_task_timeout(
self._cleanup_task.job_exes)
if self._cleanup_task.has_ended:
self._cleanup_task = None
elif self._health_task and self._health_task.id == task.id:
logger.warning('Health check task on node %s timed out',
self._hostname)
if self._health_task.has_ended:
self._health_task = None
self._last_health_task = now()
self._conditions.handle_health_task_timeout()
elif self._pull_task and self._pull_task.id == task.id:
logger.warning('Scale image pull task on node %s timed out',
self._hostname)
if self._pull_task.has_ended:
self._pull_task = None
self._conditions.handle_pull_task_timeout()
self._update_state()
def handle_task_update(self, task_update):
"""Handles the given task update
:param task_update: The task update
:type task_update: :class:`job.tasks.update.TaskStatusUpdate`
"""
with self._lock:
if self._cleanup_task and self._cleanup_task.id == task_update.task_id:
self._handle_cleanup_task_update(task_update)
elif self._health_task and self._health_task.id == task_update.task_id:
self._handle_health_task_update(task_update)
elif self._pull_task and self._pull_task.id == task_update.task_id:
self._handle_pull_task_update(task_update)
self._update_state()
def is_ready_for_new_job(self):
"""Indicates whether this node is ready to launch a new job execution
:returns: True if this node is ready to launch a new job execution, False otherwise
:rtype: bool
"""
return self._state == Node.READY
def is_ready_for_next_job_task(self):
"""Indicates whether this node is ready to launch the next task of a job execution
:returns: True if this node is ready to launch a job task, False otherwise
:rtype: bool
"""
return self._state not in [Node.DEPRECATED, Node.OFFLINE
] and self._is_image_pulled
def is_ready_for_system_task(self):
"""Indicates whether this node is ready to launch a new system task
:returns: True if this node is ready to launch a new system task, False otherwise
:rtype: bool
"""
return self._state == Node.READY
def should_be_removed(self):
"""Indicates whether this node should be removed from the scheduler. If the node is no longer active and is
also no longer online, there's no reason for the scheduler to continue to track it.
:returns: True if this node should be removed from the scheduler
:rtype: bool
"""
if not self._is_active and not self._is_online:
return True
elif self._last_offer_received < (now() -
datetime.timedelta(minutes=5)):
# Scale has not received an offer for the node in the last 5 min
return True
else:
return False
def update_from_mesos(self, agent_id=None, is_online=None):
"""Updates this node's data from Mesos
:param agent_id: The Mesos agent ID for the node
:type agent_id: string
:param is_online: Whether the Mesos agent is online
:type is_online: bool
"""
with self._lock:
if agent_id:
self._agent_id = agent_id
if is_online is not None:
self._is_online = is_online
from node.models import Node
if is_online:
# If node comes online, sync database node state with scheduler node state
Node.objects.update_node({'is_active': True},
node_id=self._id)
else:
# If node goes offline, sync scheduler node state with database node state and reset it
Node.objects.update_node({'is_active': False},
node_id=self._id)
self._reset_node()
self._update_state()
def update_from_model(self, node, scheduler_config):
"""Updates this node's data from the database models
:param node: The node model
:type node: :class:`node.models.Node`
:param scheduler_config: The scheduler configuration
:type scheduler_config: :class:`scheduler.configuration.SchedulerConfiguration`
"""
if self.id != node.id:
raise Exception(
'Trying to update node from incorrect database model')
with self._lock:
self._is_active = node.is_active
self._is_paused = node.is_paused
self._last_offer_received = node.last_offer_received
self._is_scheduler_paused = scheduler_config.is_paused
if not node.is_active:
# If node is deprecated, reset it
self._reset_node()
self._update_state()
def _create_next_tasks(self, when):
"""Creates the next tasks that needs to be run for this node. Caller must have obtained the thread lock.
:param when: The current time
:type when: :class:`datetime.datetime`
"""
# If we have a cleanup task, check that node's agent ID has not changed
if self._cleanup_task and self._cleanup_task.agent_id != self._agent_id:
self._cleanup_task = None
if not self._cleanup_task and self._is_ready_for_cleanup_task(when):
self._cleanup_task = self._cleanup.create_next_task(
self._agent_id, self._hostname,
self._is_initial_cleanup_completed)
# If we have a health task, check that node's agent ID has not changed
if self._health_task and self._health_task.agent_id != self._agent_id:
self._health_task = None
if not self._health_task and self._is_ready_for_health_task(when):
self._health_task = HealthTask(scheduler_mgr.framework_id,
self._agent_id)
# If we have a pull task, check that node's agent ID has not changed
if self._pull_task and self._pull_task.agent_id != self._agent_id:
self._pull_task = None
if not self._pull_task and self._is_ready_for_pull_task(when):
self._pull_task = PullTask(scheduler_mgr.framework_id,
self._agent_id)
def _image_pull_completed(self):
"""Tells this node that its image pull task has succeeded. Caller must have obtained the thread lock.
"""
logger.info('Node %s has finished pulling the Scale image',
self._hostname)
self._is_image_pulled = True
def _initial_cleanup_completed(self):
"""Tells this node that its initial cleanup task has succeeded. Caller must have obtained the thread lock.
"""
logger.info('Node %s has completed initial clean up', self._hostname)
self._is_initial_cleanup_completed = True
def _is_ready_for_cleanup_task(self, when):
"""Indicates whether this node is ready to launch a cleanup task. Caller must have obtained the thread lock.
:param when: The current time
:type when: :class:`datetime.datetime`
:returns: True if this node is ready to launch a cleanup task, False otherwise
:rtype: bool
"""
if self._state in [Node.INITIAL_CLEANUP, Node.IMAGE_PULL, Node.READY]:
return True
elif self._state == Node.DEGRADED:
# The cleanup task can be scheduled during DEGRADED state as long as the Docker daemon is OK
if self._conditions.is_daemon_bad:
return False
# Schedule cleanup task if threshold has passed since last cleanup task error
last_cleanup_error = self._conditions.last_cleanup_task_error()
if last_cleanup_error:
return when - last_cleanup_error > Node.CLEANUP_ERR_THRESHOLD
# No cleanup error
return True
return False
def _is_ready_for_health_task(self, when):
"""Indicates whether this node is ready to launch a health check task. Caller must have obtained the thread
lock.
:param when: The current time
:type when: :class:`datetime.datetime`
:returns: True if this node is ready to launch a health check task, False otherwise
:rtype: bool
"""
if self._state in [Node.DEPRECATED, Node.OFFLINE]:
return False
elif not self._conditions.is_health_check_normal:
# Schedule health task if threshold has passed since last health task error
return not self._last_health_task or (when - self._last_health_task
> Node.HEALTH_ERR_THRESHOLD)
# Node is normal, use normal threshold for when to schedule next health check
return not self._last_health_task or (when - self._last_health_task >
Node.NORMAL_HEALTH_THRESHOLD)
def _is_ready_for_pull_task(self, when):
"""Indicates whether this node is ready to launch the pull task for the Scale Docker image. Caller must have
obtained the thread lock.
:param when: The current time
:type when: :class:`datetime.datetime`
:returns: True if this node is ready to launch a pull task, False otherwise
:rtype: bool
"""
if self._state == Node.IMAGE_PULL:
return True
elif self._state == Node.DEGRADED:
# The pull task can be scheduled during DEGRADED state if other conditions match IMAGE_PULL state and the
# DEGRADED errors do not affect the ability to do an image pull
# Make sure initial cleanup is done, image pull is not done, and image pull on the node works
if not self._is_initial_cleanup_completed or self._is_image_pulled or self._conditions.is_pull_bad:
return False
# Schedule pull task if threshold has passed since last pull task error
last_pull_error = self._conditions.last_image_pull_task_error()
if last_pull_error:
return when - last_pull_error > Node.IMAGE_PULL_ERR_THRESHOLD
# No pull error
return True
return False
def _handle_cleanup_task_update(self, task_update):
"""Handles the given task update for a cleanup task. Caller must have obtained the thread lock.
:param task_update: The cleanup task update
:type task_update: :class:`job.tasks.update.TaskStatusUpdate`
"""
if task_update.status == TaskStatusUpdate.FINISHED:
if self._cleanup_task.is_initial_cleanup:
self._initial_cleanup_completed()
else:
# Clear job executions that were cleaned up
self._cleanup.delete_job_executions(
self._cleanup_task.job_exes)
self._conditions.update_cleanup_count(
self._cleanup.get_num_job_exes())
self._conditions.handle_cleanup_task_completed()
elif task_update.status == TaskStatusUpdate.FAILED:
logger.warning('Cleanup task on node %s failed', self._hostname)
self._conditions.handle_cleanup_task_failed(
self._cleanup_task.job_exes)
elif task_update.status == TaskStatusUpdate.KILLED:
logger.warning('Cleanup task on node %s killed', self._hostname)
elif task_update.status == TaskStatusUpdate.LOST:
logger.warning('Cleanup task on node %s lost', self._hostname)
self._cleanup_task = None
if self._cleanup_task and self._cleanup_task.has_ended:
self._cleanup_task = None
def _handle_health_task_update(self, task_update):
"""Handles the given task update for a health check task. Caller must have obtained the thread lock.
:param task_update: The health check task update
:type task_update: :class:`job.tasks.update.TaskStatusUpdate`
"""
if task_update.status == TaskStatusUpdate.FINISHED:
self._last_health_task = now()
self._conditions.handle_health_task_completed()
elif task_update.status == TaskStatusUpdate.FAILED:
logger.warning('Health check task on node %s failed',
self._hostname)
self._last_health_task = now()
self._conditions.handle_health_task_failed(task_update)
elif task_update.status == TaskStatusUpdate.KILLED:
logger.warning('Health check task on node %s killed',
self._hostname)
elif task_update.status == TaskStatusUpdate.LOST:
logger.warning('Health check task on node %s lost', self._hostname)
self._health_task = None
if self._health_task and self._health_task.has_ended:
self._health_task = None
def _handle_pull_task_update(self, task_update):
"""Handles the given task update for a pull task. Caller must have obtained the thread lock.
:param task_update: The pull task update
:type task_update: :class:`job.tasks.update.TaskStatusUpdate`
"""
if task_update.status == TaskStatusUpdate.FINISHED:
self._image_pull_completed()
self._conditions.handle_pull_task_completed()
elif task_update.status == TaskStatusUpdate.FAILED:
logger.warning('Scale image pull task on node %s failed',
self._hostname)
self._conditions.handle_pull_task_failed()
elif task_update.status == TaskStatusUpdate.KILLED:
logger.warning('Scale image pull task on node %s killed',
self._hostname)
elif task_update.status == TaskStatusUpdate.LOST:
logger.warning('Scale image pull task on node %s lost',
self._hostname)
self._pull_task = None
if self._pull_task and self._pull_task.has_ended:
self._pull_task = None
def _reset_node(self):
"""Resets the node if it goes away so initial cleanup and the Scale image pull occur when the node comes back.
Caller must have obtained the node's thread lock.
"""
self._cleanup = NodeCleanup()
self._cleanup_task = None
self._health_task = None
self._is_image_pulled = False
self._is_initial_cleanup_completed = False
self._last_health_task = None
self._pull_task = None
def _update_state(self):
"""Updates the node's state. Caller must have obtained the node's thread lock.
"""
old_state = self._state
if not self._is_active:
self._state = self.DEPRECATED
elif not self._is_online:
self._state = self.OFFLINE
elif self._is_paused:
self._state = self.PAUSED
elif self._is_scheduler_paused:
self._state = self.SCHEDULER_STOPPED
elif self._conditions.has_active_errors():
self._state = self.DEGRADED
elif not self._is_initial_cleanup_completed:
self._state = self.INITIAL_CLEANUP
elif not self._is_image_pulled:
self._state = self.IMAGE_PULL
else:
self._state = self.READY
if old_state and old_state != self._state:
if self._state == self.DEGRADED:
logger.warning('Node %s is now in %s state', self._hostname,
self._state.state)
else:
logger.info('Node %s is now in %s state', self._hostname,
self._state.state)
def test_handle_lost_tasks(self):
"""Tests handling lost cleanup tasks"""
node = Node(self.node_agent, self.node)
node_cleanup = NodeCleanup(node)
# Get initial cleanup task
task = node_cleanup.get_next_task()
task_1_id = task.id
self.assertIsNotNone(task)
# Lose task without scheduling and get same task again
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.LOST, now())
node_cleanup.handle_task_update(update)
task = node_cleanup.get_next_task()
self.assertIsNotNone(task)
self.assertEqual(task.id, task_1_id)
self.assertFalse(node.is_initial_cleanup_completed)
# Lose task with scheduling and get same task again
task.launch(now())
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.LOST, now())
node_cleanup.handle_task_update(update)
task = node_cleanup.get_next_task()
self.assertIsNotNone(task)
self.assertEqual(task.id, task_1_id)
self.assertFalse(node.is_initial_cleanup_completed)
# Lose task after running and get same task again
task.launch(now())
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.RUNNING, now())
node_cleanup.handle_task_update(update)
update = job_test_utils.create_task_status_update(task.id, task.agent_id, TaskStatusUpdate.LOST, now())
node_cleanup.handle_task_update(update)
task = node_cleanup.get_next_task()
self.assertIsNotNone(task)
self.assertEqual(task.id, task_1_id)
self.assertFalse(node.is_initial_cleanup_completed)
