heat/heat/engine/worker.py

382 lines
15 KiB
Python

# Copyright (c) 2014 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from oslo_log import log as logging
import oslo_messaging
from oslo_service import service
from osprofiler import profiler
import six
from heat.common import context
from heat.common import exception
from heat.common.i18n import _LE
from heat.common.i18n import _LI
from heat.common import messaging as rpc_messaging
from heat.engine import resource
from heat.engine import scheduler
from heat.engine import stack as parser
from heat.engine import sync_point
from heat.objects import resource as resource_objects
from heat.rpc import listener_client
from heat.rpc import worker_client as rpc_client
LOG = logging.getLogger(__name__)
@profiler.trace_cls("rpc")
class WorkerService(service.Service):
"""
This service is dedicated to handle internal messages to the 'worker'
(a.k.a. 'converger') actor in convergence. Messages on this bus will
use the 'cast' rather than 'call' method to anycast the message to
an engine that will handle it asynchronously. It won't wait for
or expect replies from these messages.
"""
RPC_API_VERSION = '1.2'
def __init__(self,
host,
topic,
engine_id,
thread_group_mgr):
super(WorkerService, self).__init__()
self.host = host
self.topic = topic
self.engine_id = engine_id
self.thread_group_mgr = thread_group_mgr
self._rpc_client = rpc_client.WorkerClient()
self._rpc_server = None
self.target = None
def start(self):
target = oslo_messaging.Target(
version=self.RPC_API_VERSION,
server=self.host,
topic=self.topic)
self.target = target
LOG.info(_LI("Starting %(topic)s (%(version)s) in engine %(engine)s."),
{'topic': self.topic,
'version': self.RPC_API_VERSION,
'engine': self.engine_id})
self._rpc_server = rpc_messaging.get_rpc_server(target, self)
self._rpc_server.start()
super(WorkerService, self).start()
def stop(self):
# Stop rpc connection at first for preventing new requests
LOG.info(_LI("Stopping %(topic)s in engine %(engine)s."),
{'topic': self.topic, 'engine': self.engine_id})
try:
self._rpc_server.stop()
self._rpc_server.wait()
except Exception as e:
LOG.error(_LE("%(topic)s is failed to stop, %(exc)s"),
{'topic': self.topic, 'exc': e})
super(WorkerService, self).stop()
def _try_steal_engine_lock(self, cnxt, resource_id):
rs_obj = resource_objects.Resource.get_obj(cnxt,
resource_id)
if (rs_obj.engine_id != self.engine_id and
rs_obj.engine_id is not None):
if not listener_client.EngineListenerClient(
rs_obj.engine_id).is_alive(cnxt):
# steal the lock.
rs_obj.update_and_save({'engine_id': None})
return True
return False
def _trigger_rollback(self, stack):
LOG.info(_LI("Triggering rollback of %(stack_name)s %(action)s "),
{'action': stack.action, 'stack_name': stack.name})
stack.rollback()
def _handle_failure(self, cnxt, stack, failure_reason):
stack.state_set(stack.action, stack.FAILED, failure_reason)
if (not stack.disable_rollback and
stack.action in (stack.CREATE, stack.ADOPT, stack.UPDATE)):
self._trigger_rollback(stack)
else:
stack.purge_db()
def _handle_resource_failure(self, cnxt, stack_id, traversal_id,
failure_reason):
stack = parser.Stack.load(cnxt, stack_id=stack_id)
# make sure no new stack operation was triggered
if stack.current_traversal != traversal_id:
return
self._handle_failure(cnxt, stack, failure_reason)
def _handle_stack_timeout(self, cnxt, stack):
failure_reason = u'Timed out'
self._handle_failure(cnxt, stack, failure_reason)
def _load_resource(self, cnxt, resource_id, resource_data, is_update):
if is_update:
cache_data = {in_data.get(
'name'): in_data for in_data in resource_data.values()
if in_data is not None}
else:
# no data to resolve in cleanup phase
cache_data = {}
rsrc, stack = None, None
try:
rsrc, stack = resource.Resource.load(cnxt, resource_id, is_update,
cache_data)
except (exception.ResourceNotFound, exception.NotFound):
pass # can be ignored
return rsrc, stack
def _do_check_resource(self, cnxt, current_traversal, tmpl, resource_data,
is_update, rsrc, stack, adopt_stack_data):
try:
if is_update:
try:
check_resource_update(rsrc, tmpl.id, resource_data,
self.engine_id,
stack.time_remaining())
except resource.UpdateReplace:
new_res_id = rsrc.make_replacement(tmpl.id)
LOG.info("Replacing resource with new id %s", new_res_id)
rpc_data = sync_point.serialize_input_data(resource_data)
self._rpc_client.check_resource(cnxt,
new_res_id,
current_traversal,
rpc_data, is_update,
adopt_stack_data)
return False
else:
check_resource_cleanup(rsrc, tmpl.id, resource_data,
self.engine_id, stack.time_remaining())
return True
except resource.UpdateInProgress:
if self._try_steal_engine_lock(cnxt, rsrc.id):
rpc_data = sync_point.serialize_input_data(resource_data)
self._rpc_client.check_resource(cnxt,
rsrc.id,
current_traversal,
rpc_data, is_update,
adopt_stack_data)
except exception.ResourceFailure as ex:
reason = 'Resource %s failed: %s' % (rsrc.action,
six.text_type(ex))
self._handle_resource_failure(
cnxt, stack.id, current_traversal, reason)
except scheduler.Timeout:
# reload the stack to verify current traversal
stack = parser.Stack.load(cnxt, stack_id=stack.id)
if stack.current_traversal != current_traversal:
return
self._handle_stack_timeout(cnxt, stack)
return False
def _retrigger_check_resource(self, cnxt, is_update, resource_id, stack):
current_traversal = stack.current_traversal
graph = stack.convergence_dependencies.graph()
key = (resource_id, is_update)
predecessors = graph[key]
def do_check(target_key, data):
self.check_resource(resource_id, current_traversal,
data)
try:
sync_point.sync(cnxt, resource_id, current_traversal, is_update,
do_check, predecessors, {key: None})
except sync_point.SyncPointNotFound:
pass
def _initiate_propagate_resource(self, cnxt, resource_id,
current_traversal, is_update, rsrc,
stack):
deps = stack.convergence_dependencies
graph = deps.graph()
graph_key = (resource_id, is_update)
if graph_key not in graph and rsrc.replaces is not None:
# If we are a replacement, impersonate the replaced resource for
# the purposes of calculating whether subsequent resources are
# ready, since everybody has to work from the same version of the
# graph. Our real resource ID is sent in the input_data, so the
# dependencies will get updated to point to this resource in time
# for the next traversal.
graph_key = (rsrc.replaces, is_update)
def _get_input_data(req, fwd):
if fwd:
return construct_input_data(rsrc)
else:
# Don't send data if initiating clean-up for self i.e.
# initiating delete of a replaced resource
if req not in graph_key:
# send replaced resource as needed_by if it exists
return (rsrc.replaced_by
if rsrc.replaced_by is not None
else resource_id)
return None
try:
for req, fwd in deps.required_by(graph_key):
input_data = _get_input_data(req, fwd)
propagate_check_resource(
cnxt, self._rpc_client, req, current_traversal,
set(graph[(req, fwd)]), graph_key, input_data, fwd,
stack.adopt_stack_data)
check_stack_complete(cnxt, stack, current_traversal,
resource_id, deps, is_update)
except sync_point.SyncPointNotFound:
# Reload the stack to determine the current traversal, and check
# the SyncPoint for the current node to determine if it is ready.
# If it is, then retrigger the current node with the appropriate
# data for the latest traversal.
stack = parser.Stack.load(cnxt, stack_id=rsrc.stack.id)
if current_traversal == stack.current_traversal:
LOG.debug('[%s] Traversal sync point missing.',
current_traversal)
return
self._retrigger_check_resource(cnxt, is_update, resource_id, stack)
@context.request_context
def check_resource(self, cnxt, resource_id, current_traversal, data,
is_update, adopt_stack_data):
'''
Process a node in the dependency graph.
The node may be associated with either an update or a cleanup of its
associated resource.
'''
resource_data = dict(sync_point.deserialize_input_data(data))
rsrc, stack = self._load_resource(cnxt, resource_id, resource_data,
is_update)
if rsrc is None:
return
if current_traversal != stack.current_traversal:
LOG.debug('[%s] Traversal cancelled; stopping.', current_traversal)
return
if stack.has_timed_out():
self._handle_stack_timeout(cnxt, stack)
return
tmpl = stack.t
stack.adopt_stack_data = adopt_stack_data
if is_update:
if (rsrc.replaced_by is not None and
rsrc.current_template_id != tmpl.id):
return
check_resource_done = self._do_check_resource(cnxt, current_traversal,
tmpl, resource_data,
is_update,
rsrc, stack,
adopt_stack_data)
if check_resource_done:
# initiate check on next set of resources from graph
self._initiate_propagate_resource(cnxt, resource_id,
current_traversal, is_update,
rsrc, stack)
def construct_input_data(rsrc):
attributes = rsrc.stack.get_dep_attrs(
six.itervalues(rsrc.stack.resources),
rsrc.stack.outputs,
rsrc.name)
resolved_attributes = {}
for attr in attributes:
try:
resolved_attributes[attr] = rsrc.FnGetAtt(attr)
except exception.InvalidTemplateAttribute as ita:
LOG.info(six.text_type(ita))
input_data = {'id': rsrc.id,
'name': rsrc.name,
'reference_id': rsrc.FnGetRefId(),
'attrs': resolved_attributes}
return input_data
def check_stack_complete(cnxt, stack, current_traversal, sender_id, deps,
is_update):
'''
Mark the stack complete if the update is complete.
Complete is currently in the sense that all desired resources are in
service, not that superfluous ones have been cleaned up.
'''
roots = set(deps.roots())
if (sender_id, is_update) not in roots:
return
def mark_complete(stack_id, data):
stack.mark_complete(current_traversal)
sender_key = (sender_id, is_update)
sync_point.sync(cnxt, stack.id, current_traversal, True,
mark_complete, roots, {sender_key: None})
def propagate_check_resource(cnxt, rpc_client, next_res_id,
current_traversal, predecessors, sender_key,
sender_data, is_update, adopt_stack_data):
'''
Trigger processing of a node if all of its dependencies are satisfied.
'''
def do_check(entity_id, data):
rpc_client.check_resource(cnxt, entity_id, current_traversal,
data, is_update, adopt_stack_data)
sync_point.sync(cnxt, next_res_id, current_traversal,
is_update, do_check, predecessors,
{sender_key: sender_data})
def check_resource_update(rsrc, template_id, resource_data, engine_id,
timeout):
'''
Create or update the Resource if appropriate.
'''
if rsrc.action == resource.Resource.INIT:
rsrc.create_convergence(template_id, resource_data, engine_id, timeout)
else:
rsrc.update_convergence(template_id, resource_data, engine_id, timeout)
def check_resource_cleanup(rsrc, template_id, resource_data, engine_id,
timeout):
'''
Delete the Resource if appropriate.
'''
rsrc.delete_convergence(template_id, resource_data, engine_id, timeout)