openstack
/
heat
Code Issues Proposed changes

Do updates based on a single dependency list 

This ensures that updates proceed in the correct order with maximum
parallelism, for arbitrarily complex dependency graphs.

Change-Id: Ia11f4cfef58a3045199e1e5e49050cb1646f5057
This commit is contained in:
Zane Bitter 2013-08-30 20:50:11 +02:00
parent 752da8e0c1
commit 8b732241df
1 changed files with 72 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

119
heat/engine/update.py
View File

@ -15,6 +15,7 @@
from heat.db import api as db_api
from heat.engine import dependencies
from heat.engine import resource
from heat.engine import scheduler
@ -50,32 +51,29 @@ class StackUpdate(object):
def __call__(self):
"""Return a co-routine that updates the stack."""
existing_deps = self.existing_stack.dependencies
new_deps = self.new_stack.dependencies
cleanup_prev = scheduler.DependencyTaskGroup(
self.previous_stack.dependencies,
self._remove_backup_resource,
reverse=True)
cleanup = scheduler.DependencyTaskGroup(existing_deps,
self._remove_old_resource,
reverse=True)
create_new = scheduler.DependencyTaskGroup(new_deps,
self._create_new_resource)
update = scheduler.DependencyTaskGroup(new_deps,
self._update_resource)
update = scheduler.DependencyTaskGroup(self.dependencies(),
self._resource_update)
if not self.rollback:
yield cleanup_prev()
yield create_new()
try:
yield update()
finally:
prev_deps = self.previous_stack._get_dependencies(
self.previous_stack.resources.itervalues())
self.previous_stack.dependencies = prev_deps
yield cleanup()
def _resource_update(self, res):
if res.name in self.new_stack and self.new_stack[res.name] is res:
return self._process_new_resource_update(res)
else:
return self._process_existing_resource_update(res)
@scheduler.wrappertask
def _remove_backup_resource(self, prev_res):
@ -84,27 +82,6 @@ class StackUpdate(object):
logger.debug("Deleting backup resource %s" % prev_res.name)
yield prev_res.destroy()
@scheduler.wrappertask
def _remove_old_resource(self, existing_res):
res_name = existing_res.name
if res_name in self.previous_stack:
yield self._remove_backup_resource(self.previous_stack[res_name])
if res_name not in self.new_stack:
logger.debug("resource %s not found in updated stack"
% res_name + " definition, deleting")
yield existing_res.destroy()
del self.existing_stack.resources[res_name]
@scheduler.wrappertask
def _create_new_resource(self, new_res):
res_name = new_res.name
if res_name not in self.existing_stack:
logger.debug("resource %s not found in current stack"
% res_name + " definition, adding")
yield self._create_resource(new_res)
@staticmethod
def _exchange_stacks(existing_res, prev_res):
db_api.resource_exchange_stacks(existing_res.stack.context,
@ -147,24 +124,72 @@ class StackUpdate(object):
yield new_res.create()
@scheduler.wrappertask
def _update_resource(self, new_res):
def _process_new_resource_update(self, new_res):
res_name = new_res.name
if res_name not in self.existing_snippets:
return
# Compare resolved pre/post update resource snippets,
# note the new resource snippet is resolved in the context
# of the existing stack (which is the stack being updated)
existing_snippet = self.existing_snippets[res_name]
new_snippet = self.existing_stack.resolve_runtime_data(new_res.t)
if new_snippet != existing_snippet:
if res_name in self.existing_stack:
existing_res = self.existing_stack[res_name]
try:
yield self.existing_stack[res_name].update(new_snippet,
existing_snippet)
yield self._update_in_place(existing_res,
new_res)
except resource.UpdateReplace:
yield self._create_resource(new_res)
pass
else:
logger.info("Resource %s for stack %s updated" %
(res_name, self.existing_stack.name))
return
yield self._create_resource(new_res)
@scheduler.wrappertask
def _update_in_place(self, existing_res, new_res):
# Compare resolved pre/post update resource snippets,
# note the new resource snippet is resolved in the context
# of the existing stack (which is the stack being updated)
existing_snippet = self.existing_snippets[existing_res.name]
new_snippet = self.existing_stack.resolve_runtime_data(new_res.t)
if new_snippet != existing_snippet:
yield existing_res.update(new_snippet, existing_snippet)
@scheduler.wrappertask
def _process_existing_resource_update(self, existing_res):
res_name = existing_res.name
if res_name in self.previous_stack:
yield self._remove_backup_resource(self.previous_stack[res_name])
if res_name in self.new_stack:
new_res = self.new_stack[res_name]
if new_res.state == (new_res.INIT, new_res.COMPLETE):
# Already updated in-place
return
if existing_res.stack is not self.previous_stack:
yield existing_res.destroy()
if res_name not in self.new_stack:
del self.existing_stack.resources[res_name]
def dependencies(self):
'''
Return a Dependencies object representing the dependencies between
update operations to move from an existing stack definition to a new
one.
'''
existing_deps = self.existing_stack.dependencies
new_deps = self.new_stack.dependencies
def edges():
# Create/update the new stack's resources in create order
for e in new_deps.graph().edges():
yield e
# Destroy/cleanup the old stack's resources in delete order
for e in existing_deps.graph(reverse=True).edges():
yield e
# Don't cleanup old resources until after they have been replaced
for res in self.existing_stack:
if res.name in self.new_stack:
yield (res, self.new_stack[res.name])
return dependencies.Dependencies(edges())