openstack/manila
Code Issues Proposed changes

Allow configuration of a back end specific availability zone

Browse Source 
"storage_availability_zone" in the [DEFAULT] section of
manila's configuration file has allowed deployers to configure
and manage both service (scheduler, share manager) and storage
system availability. However, quite often manila's services
(api, scheduler, share and data managers) are run on a dedicated
control plane that is a different failure domain from that of
the storage that manila manages.

Also, when using share replication, deployers would need to
run multiple manila share manager services with different
configuration files, each with their own
"storage_availability_zone".

To allow flexibility of separating service and storage
availability zones, we introduce a new configuration option
"backend_availability_zone" within the share driver/backend
section. When this option is used, it will override the value
of the "storage_availability_zone" from the [DEFAULT] section.

Change-Id: Ice99a880dd7be7af94dea86b31a6db88be3d7d9b
Implements: bp per-backend-availability-zones
This commit is contained in:
Goutham Pacha Ravi 2019-01-10 17:22:23 -08:00
parent 8f88779778
commit a75fe3d7cc
10 changed files with 64 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
doc/source/admin/shared-file-systems-share-replication.rst
View File

@ -122,7 +122,7 @@ The following examples have been implemented with the ZFSonLinux driver that
is a reference implementation in the Shared File Systems service. It operates
in ``driver_handles_share_servers=False`` mode and supports the ``readable``
type of replication. In the example, we assume a configuration of two
Availability Zones (configuration option: ``storage_availability_zone``),
Availability Zones [1]_,
called `availability_zone_1` and `availability_zone_2`.
Multiple availability zones are not necessary to use the replication feature.
@ -598,3 +598,14 @@ replica's ID to delete a share replica.
.. note::
You cannot delete the last ``active`` replica with this command. You should
use the :command:`manila delete` command to remove the share.
.. [1] When running in a multi-backend configuration, until the Stein
release, deployers could only configure one Availability Zone per manila
configuration file. This is achieved with the option
``storage_availability_zone`` defined under the ``[DEFAULT]`` section.
Beyond the Stein release, the option ``backend_availability_zone``
can be specified in each back end stanza. The value of this
configuration option will override any configuration of the
``storage_availability_zone`` from the ``[DEFAULT]`` section.

5
doc/source/contributor/share_replication.rst
View File

@ -56,8 +56,9 @@ pools, manila would allow for replication between two pools on the same
backend.
The ``replication_domain`` option is meant to be used in conjunction with the
``storage_availability_zone`` option to utilize this solution for Data
Protection/Disaster Recovery.
``storage_availability_zone`` (or back end specific
``backend_availability_zone``) option to utilize
this solution for Data Protection/Disaster Recovery.
Replication types

1
manila/manager.py
View File

@ -91,6 +91,7 @@ class Manager(base.Base, PeriodicTasks):
host = CONF.host
self.host = host
self.additional_endpoints = []
self.availability_zone = CONF.storage_availability_zone
super(Manager, self).__init__(db_driver)
def periodic_tasks(self, context, raise_on_error=False):

22
manila/service.py
View File

@ -92,6 +92,7 @@ class Service(service.Service):
self.manager = manager_class(host=self.host,
service_name=service_name,
*args, **kwargs)
self.availability_zone = self.manager.availability_zone
self.report_interval = report_interval
self.periodic_interval = periodic_interval
self.periodic_fuzzy_delay = periodic_fuzzy_delay
@ -145,13 +146,14 @@ class Service(service.Service):
self.timers.append(periodic)
def _create_service_ref(self, context):
zone = CONF.storage_availability_zone
service_ref = db.service_create(context,
{'host': self.host,
'binary': self.binary,
'topic': self.topic,
'report_count': 0,
'availability_zone': zone})
service_args = {
'host': self.host,
'binary': self.binary,
'topic': self.topic,
'report_count': 0,
'availability_zone': self.availability_zone
}
service_ref = db.service_create(context, service_args)
self.service_id = service_ref['id']
def __getattr__(self, key):
@ -244,7 +246,6 @@ class Service(service.Service):
def report_state(self):
"""Update the state of this service in the datastore."""
ctxt = context.get_admin_context()
zone = CONF.storage_availability_zone
state_catalog = {}
try:
try:
@ -256,8 +257,9 @@ class Service(service.Service):
service_ref = db.service_get(ctxt, self.service_id)
state_catalog['report_count'] = service_ref['report_count'] + 1
if zone != service_ref['availability_zone']['name']:
state_catalog['availability_zone'] = zone
if (self.availability_zone !=
service_ref['availability_zone']['name']):
state_catalog['availability_zone'] = self.availability_zone
db.service_update(ctxt,
self.service_id, state_catalog)

5
manila/share/driver.py
View File

@ -126,6 +126,11 @@ share_opts = [
"replication between each other. If this option is not "
"specified in the group, it means that replication is not "
"enabled on the backend."),
cfg.StrOpt('backend_availability_zone',
default=None,
help='Availability zone for this share backend. If not set, '
'the ``storage_availability_zone`` option from the '
'``[DEFAULT]`` section is used.'),
cfg.StrOpt('filter_function',
help='String representation for an equation that will be '
'used to filter hosts.'),

5
manila/share/drivers/service_instance.py
View File

@ -219,6 +219,9 @@ class ServiceInstanceManager(object):
self.max_time_to_build_instance = self.get_config_option(
"max_time_to_build_instance")
self.availability_zone = self.get_config_option(
'backend_availability_zone') or CONF.storage_availability_zone
if self.get_config_option("driver_handles_share_servers"):
self.path_to_public_key = self.get_config_option(
"path_to_public_key")
@ -564,7 +567,7 @@ class ServiceInstanceManager(object):
flavor=self.get_config_option("service_instance_flavor_id"),
key_name=key_name,
nics=network_data['nics'],
availability_zone=CONF.storage_availability_zone,
availability_zone=self.availability_zone,
**create_kwargs)
fail_safe_data['instance_id'] = service_instance['id']

14
manila/share/manager.py
View File

@ -239,6 +239,12 @@ class ShareManager(manager.SchedulerDependentManager):
configuration=self.configuration,
)
backend_availability_zone = self.driver.configuration.safe_get(
'backend_availability_zone')
self.availability_zone = (
backend_availability_zone or CONF.storage_availability_zone
)
self.access_helper = access.ShareInstanceAccess(self.db, self.driver)
self.snapshot_access_helper = (
snapshot_access.ShareSnapshotInstanceAccess(self.db, self.driver))
@ -1659,7 +1665,7 @@ class ShareManager(manager.SchedulerDependentManager):
if not share_instance['availability_zone']:
share_instance = self.db.share_instance_update(
context, share_instance_id,
{'availability_zone': CONF.storage_availability_zone},
{'availability_zone': self.availability_zone},
with_share_data=True
)
@ -1834,7 +1840,7 @@ class ShareManager(manager.SchedulerDependentManager):
if not share_replica['availability_zone']:
share_replica = self.db.share_replica_update(
context, share_replica['id'],
{'availability_zone': CONF.storage_availability_zone},
{'availability_zone': self.availability_zone},
with_share_data=True
)
@ -2400,7 +2406,7 @@ class ShareManager(manager.SchedulerDependentManager):
share_update.update({
'status': constants.STATUS_AVAILABLE,
'launched_at': timeutils.utcnow(),
'availability_zone': CONF.storage_availability_zone,
'availability_zone': self.availability_zone,
})
# If the share was managed with `replication_type` extra-spec, the
@ -3865,7 +3871,7 @@ class ShareManager(manager.SchedulerDependentManager):
def _get_az_for_share_group(self, context, share_group_ref):
if not share_group_ref['availability_zone_id']:
return self.db.availability_zone_get(
context, CONF.storage_availability_zone)['id']
context, self.availability_zone)['id']
return share_group_ref['availability_zone_id']
@utils.require_driver_initialized

2
manila/tests/share/drivers/test_service_instance.py
View File

@ -75,6 +75,8 @@ def fake_get_config_option(key):
return None
elif key == 'admin_subnet_id':
return None
elif key == 'backend_availability_zone':
return None
else:
return mock.Mock()

2
manila/tests/share/test_manager.py
View File

@ -990,7 +990,7 @@ class ShareManagerTestCase(test.TestCase):
replica_2 = fake_replica(id='fake2')
self.mock_object(db, 'share_replicas_get_all_by_share',
mock.Mock(return_value=[replica, replica_2]))
manager.CONF.set_default('storage_availability_zone', 'fake_az')
self.share_manager.availability_zone = 'fake_az'
fake_access_rules = [{'id': '1'}, {'id': '2'}, {'id': '3'}]
self.mock_object(db, 'share_replica_get',
mock.Mock(return_value=replica))

14
releasenotes/notes/per-backend-az-590c68be0e2cb4bd.yaml Normal file
View File

@ -0,0 +1,14 @@
---
features:
- |
Availability zones may now be configured per backend in a multi-backend
configuration. Individual back end sections can now have the configuration
option ``backend_availability_zone`` set. If set, this value will override
the ``storage_availability_zone`` option from the [DEFAULT] section.
upgrade:
- The ``storage_availability_zone`` option can now be overridden per
backend by using the ``backend_availability_zone`` option within the
backend stanza. This allows enabling multiple storage backends that may
be deployed in different AZs in the same ``manila.conf`` file if
desired, simplifying service architecture around the Share Replication
feature.