openstack/tacker-specs
Code Issues Proposed changes

Fix Spec of "Enhance Placement Process"

Browse Source 
"Enhance Placement Process" has the following spec changes in Antelope.
* In AZ reselection, randomly select from unselected AZs without
  considering Affinity/Anti-Affinity
* Only StandardUserData is the target of reselection processing
  (Delete the description of AutoScalingGroup)
* Delete the configuration value for whether to reselect AZ

This patch fixes these changes and moves spec of
"Enhance Placement Process" to the directory for 2023.1.

Implements: blueprint enhance-placement
Change-Id: I3629f17e8df17a2947100215e4ad7556fa812124
This commit is contained in:
Ai Hamano 2022-12-13 09:03:34 +09:00
parent 949c4ce423
commit 7cdebc9719
1 changed files with 132 additions and 116 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

248
specs/zed/enhance_placement_process.rst → specs/2023.1/enhance_placement_process.rst
View File

@ -75,9 +75,14 @@ The VNFLCM v2 API (instantiate/heal/scale for VNF) process can change
the availability zone to be used from the one notified by the NFVO if
necessary.
If the availability zone notified by the NFVO has insufficient
resources, the VNF is created/updated in a different availability zone.
The availability zone is reselected considering Affinity/Anti-Affinity
and re-create/update until there are no more candidates.
resources, the VNF is re-created/updated in a different availability
zone.
The availability zone is reselected and the VNF is re-created/updated
until there are no more candidates.
.. note::
Availability zone reselection is valid only when StandardUserData is
specified for the user data class.
1) Flowchart of availability zone reselection
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@ -115,21 +120,25 @@ flow:
#. Execute "stack create/update" in the availability zone notified by
the NFVO.
#. If an error occurs in 1, get the availability zone list.
#. If an insufficient resource error occurs in 1, get the availability
zone list.
Availability zone list details are described in :ref:`2) Get and
manage availability zone list<az-list>`.
#. Select an availability zone (excluding the Availability Zone where
the error occurred) randomly in compliance with
Affinity/Anti-Affinity from the availability zone list obtained in 2,
#. Select an availability zone (excluding the availability zone where
the error occurred) from the availability zone list obtained in 2,
and re-execute “stack create/update”.
Reselection policy details are described in :ref:`3) Availability
zone reselection policy<reselection-policy>`.
#. If "stack create/update" in the availability zone reselected in 3
becomes an error, reselect the availability zone and repeat until
"stack create/update" succeeds or until all availability zone
candidates fail.
Detecting error details are described in :ref:`4) Detection method
of insufficient resource error<detection-method>`.
becomes an insufficient resource error, reselect the availability
zone and repeat until "stack create/update" succeeds or until all
availability zone candidates fail.
.. note::
Detecting error details are described in :ref:`4) Detection method
of insufficient resource error<detection-method>`.
If the error is other than insufficient resource error, the process
ends(fails) without reselecting availability zones.
.. _az-list:
@ -192,8 +201,12 @@ flow:
3) Availability zone reselection policy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Availability zones in error are excluded from the reselection
candidates, and Availability zones are reselected randomly in compliance
with Affinity/Anti-Affinity of PlacementConstraint.
candidates, and are reselected preferentially from unselected
availability zones.
.. note::
Affinity/Anti-Affinity of PlacementConstraint and resource states of
availability zones are not considered during reselection.
The availability zone in error can be identified in the following way.
@ -204,63 +217,138 @@ The availability zone in error can be identified in the following way.
3. Identify the availability zone by the VDU identified in 2.
.. note::
Insufficient resource in availability zones that once failed during
reselection attempts may be resolved, but the availability zones will
not be reselected.
In Scale/Heal operations, VDUs that have already been deployed will
not be re-created.
Availability zone reselection for each PlacementConstraint is as
follows.
Availability zone reselection for each VNFLCM v2 API
(instantiate/heal/scale for VNF) is as follows.
Precondition: availability zone AZ-1/AZ-2/AZ-3 exist and VNF VDU-1/VDU-2
are deployed
Precondition: availability zone AZ-1/AZ-2/AZ-3/AZ-4/AZ-5 exist and VNF
VDU1-0/VDU1-1/VDU2-0/VDU2-1 are deployed
+ PlacementConstraint is Anti-Affinity
.. note::
VNFs in VDU1 are in the same availability zone (Affinity), and VNFs in
VDU2 and VDU1/VDU2 are in different availability zones (Anti-Affinity).
+ Instantiate
+ Before reselection, the following attempts to deploy failed (AZ-1
has insufficient resource)
and AZ-2 have insufficient resource)
+ VDU-1: AZ-1
+ VDU1-0: AZ-1
+ VDU1-1: AZ-1
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ VDU-2: AZ-2
+ VDU1-0/1: Reselect the following (except AZ-1/AZ-2/AZ-3, select AZ-4
or AZ-5)
+ Reselect the following (except AZ-1, select AZ-2/AZ-3 in compliance
with Anti-Affinity)
+ VDU1-0: AZ-4
+ VDU1-1: AZ-4
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ VDU-1: AZ-2
+ VDU2-0: Reselect the following (except AZ-2/AZ-3/AZ-4, select AZ-1 or
AZ-5)
+ VDU-2: AZ-3
+ VDU1-0: AZ-4
+ VDU1-1: AZ-4
+ VDU2-0: AZ-5
+ VDU2-1: AZ-3
.. note::
.. note::
The above is an example, and the reselection target is randomly
selected from unselected availability zones.
The above is an example, and it is possible that the reverse
availability zones are selected for VDU-1 and VDU-2, but it is
guaranteed that they will not be the same availability zone.
+ Heal(VDU1-1/VDU2-0)
+ Before reselection, the following attempts to deploy failed (AZ-1
and AZ-2 have insufficient resource)
+ PlacementConstraint is Affinity
+ VDU1-0: AZ-1
+ VDU1-1: AZ-1
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ Before reselection, attempt to deploy in the following and fail
(AZ-1 has insufficient resource)
+ VDU1-1: Reselect the following (except AZ-1/AZ-2/AZ-3, select AZ-4
or AZ-5)
+ VDU-1: AZ-1
+ VDU1-0: AZ-1
+ VDU1-1: AZ-4
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ VDU-2: AZ-1
.. note::
Only Heal target VNFs are targeted for availability zone
reselection.
Therefore, Affinity may not be satisfied due to the operation of
reselection.
+ Reselect the following (except AZ-1, select AZ-2/AZ-3 in compliance
with Affinity)
+ VDU2-0: Reselect the following (except AZ-1/AZ-2/AZ-3/AZ-4, select
AZ-5)
+ VDU-1: AZ-2
+ VDU1-0: AZ-1
+ VDU1-1: AZ-4
+ VDU2-0: AZ-5
+ VDU2-1: AZ-3
+ VDU-2: AZ-2
+ Scale out(add VDU1-2/VDU1-3)
.. note::
+ Before reselection, VDU1-3 deploy failed (AZ-1 has insufficient
resource)
The above is an example, and it is possible that the availability
zone AZ-3 is selected for VDU-1 and VDU-2, but it is guaranteed
that they will be the same availability zone.
+ VDU1-0: AZ-1
+ VDU1-1: AZ-1
+ VDU1-2: AZ-1
+ VDU1-3: AZ-1
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ VDU1-2/3: Reselect the following (except AZ-1/AZ-2/AZ-3, select AZ-4
or AZ-5)
+ VDU1-0: AZ-1
+ VDU1-1: AZ-1
+ VDU1-2: AZ-4
+ VDU1-3: AZ-4
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
.. note::
In the case of Affinity, even if VDU1-2 has been successfully
deployed, both VDU1-2/VDU1-3 availability zones will be reselected.
Existing VDU1-0/VDU1-1 will not be reselected, so all VDUs may not
be in the same availability zone even in Affinity case.
+ Scale out(add VDU2-2/VDU2-3)
+ Before reselection, VDU2-3 deploy failed (AZ-5 has insufficient
resource)
+ VDU1-0: AZ-1
+ VDU1-1: AZ-1
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ VDU2-2: AZ-4
+ VDU2-3: AZ-5
+ VDU2-3: Reselect the following (except AZ-5, select AZ-1 or AZ-2 or
AZ-3 or AZ-4)
+ VDU1-0: AZ-1
+ VDU1-1: AZ-1
+ VDU2-0: AZ-2
+ VDU2-1: AZ-3
+ VDU2-2: AZ-4
+ VDU2-3: AZ-1
.. note::
If there are no unselected availability zones left, randomly select
a reselection target from the selected availability zones.
In this case, Anti-Affinity cannot be satisfied.
.. _detection-method:
@ -274,7 +362,6 @@ The error message that indicates insufficient resources is extracted
from the parameter "stack_status_reason" in the response.
.. note::
In the case of insufficient resources, the error occurs after "stack
create/update" returns an acceptance response, so the "Show stack
details" response is used to detect the cause.
@ -325,73 +412,6 @@ messages as insufficient resource.
Exhausted all hosts available for retrying build failures for
instance(. \*). , Code: 500".
5) AutoScalingGroup consideration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In BaseHOT which includes AutoScalingGroup definitions, there is a
constraint that each VNFC associated with a VDU under AutoScalingGroup
cannot be set to Anti-Affinity for the availability zone.
This constraint is due to the constraint in the HOT specification that
availability zones can only be set for each VDU under the
AutoScalingGroup.
This constraint occurs not only at the time of reselection, but also at
the time of initial execution.
Therefore, BaseHOT which includes AutoScalingGroup definitions, ignores
the PlacementConstraint for each VNFC associated with a VDU and
reselects a single availability zone for each VDU under the
AutoScalingGroup. (Always set to Affinity.)
top HOT:
.. code-block::
resources:
VDU1_scale_group:
type: OS::Heat::AutoScalingGroup
properties:
min_size: 1
max_size: 3
desired_capacity: { get_param: [ nfv, VDU, VDU1, desired_capacity ] }
resource:
type: VDU1.yaml
properties:
flavor: { get_param: [ nfv, VDU, VDU1, computeFlavourId ] }
image: { get_param: [ nfv, VDU, VDU1-VirtualStorage, vcImageId ] }
zone: { get_param: [ nfv, VDU, VDU1, locationConstraints] }
net1: { get_param: [ nfv, CP, VDU1_CP1, network] }
net2: { get_param: [ nfv, CP, VDU1_CP2, network ] }
subnet1: { get_param: [nfv, CP, VDU1_CP1, fixed_ips, 0, subnet ]}
subnet2: { get_param: [nfv, CP, VDU1_CP2, fixed_ips, 0, subnet ]}
net3: { get_resource: internalVL1 }
net4: { get_resource: internalVL2 }
net5: { get_resource: internalVL3 }
nested HOT:
.. code-block::
resources:
VDU1:
type: OS::Nova::Server
properties:
flavor: { get_param: flavor }
name: VDU1
block_device_mapping_v2: [{"volume_id": { get_resource: VDU1-VirtualStorage }}]
networks:
- port:
get_resource: VDU1_CP1
- port:
get_resource: VDU1_CP2
- port:
get_resource: VDU1_CP3
- port:
get_resource: VDU1_CP4
- port:
get_resource: VDU1_CP5
availability_zone: { get_param: zone }
As shown above, top HOT specifies a single "zone" (availability zone)
for each VDU under the AutoScalingGroup, so each VNFC associated with a
VDU under the AutoScalingGroup is in the same availability zone.
.. _configuration-file:
@ -404,10 +424,6 @@ Add the following definition to the ``tacker.conf`` file.
Default value: "false"
+ Whether or not to reselect availability zone
Default value: not to reselect
+ Regular expression for detecting insufficient resource error
Default value: regular expression for insufficient resource error