x
/
powervc-driver
Code Issues Proposed changes

Timing issue in remote-keystone deployment model 

This is actually timing issue between openstack service endpoints becoming
active and powervc-driver's client initialization of those.

1. get_client() call with version_filter might runs into the 'None' client
error mentioned in the bug, which means *currently* only glance sync is
affected. When no version filtered, we do a rediscover for the svc_type.

2. get_client() call without version_filter or new_client() call just choose
the latest avaiable version service, so no 'None' client error, although the
chosen version might not be the real *latest* but the default hardcoded 'v1'
version, due to the timing issue mentioned in the bug. For the latter case,
unless there is an observation/notification mechanism or poll mechanism for
service versions update, based on current design, there is no perfect solution
as far as I can imagine.

Change-Id: I9ca0f906c8954ecd621be22445c12fd6a55a1ae7
Closes-Bug: 1358215
This commit is contained in:
Le Tian Ren 2014-08-20 15:05:35 +08:00
parent 64233b7e1c
commit 52947efccd
1 changed files with 44 additions and 7 deletions
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51
common-powervc/powervc/common/client/service.py
View File

@ -1,12 +1,16 @@
# Copyright 2013 IBM Corp.
# Copyright 2013, 2014 IBM Corp.
import urlparse
import logging
import re
import urlparse
import powervc.common.client.delegate as delegate
from glanceclient.openstack.common import importutils
from powervc.common.constants import SERVICE_TYPES as SERVICE_TYPES
from powervc.common import netutils
LOG = logging.getLogger(__name__)
class AbstractService(object):
"""a stub over a service endpoint which permits consumers
@ -227,13 +231,35 @@ class ClientServiceCatalog(object):
"""
if svc_type not in self.endpoints:
return None
def _find_version(versions, version_filter):
for version in versions.keys():
if version.find(version_filter) > -1:
return versions[version]
versions = self.endpoints[svc_type]
if version_filter is None:
# Here we need test version_filter is None or empty, use 'if not'.
if not version_filter:
return versions[max(versions, key=str)]
for version in versions.keys():
if version.find(version_filter) > -1:
return versions[version]
return None
version = _find_version(versions, version_filter)
if version is not None:
return version
# >> fix bug/1358215 - timing issue between openstack service endpoints
# becoming active and powervc-driver's client initialization of those.
# Check https://review.openstack.org/#/c/115519/ for the details.
# TODO(design): re-consider for #2 in the commit message
else:
# A lock is not necessary here. Only glance sync service use
# specified version apis and might run into this and starup_sync
# won't pass until the specified versions are ready. So there
# shouldn't be concurrent accesses to self.endpoints[svc_type] with
# svc_type='image'.
LOG.info(_("rediscover service for type:%s") % svc_type)
self._rediscover_service(svc_type)
versions = self.endpoints[svc_type]
return _find_version(versions, version_filter)
# << fix bug/1358215
def get_versions(self, svc_type):
"""return a list of the versions for the given service type
@ -416,3 +442,14 @@ class ClientServiceCatalog(object):
entry = self._normalize_catalog_entry(entry)
self.endpoints[svc_type] = \
self._build_endpoint_services(entry['url'], svc_type)
# >> fix bug/1358215, timing issue between openstack service endpoints
# becoming active and powervc-driver's client initialization of those.
def _rediscover_service(self, svc_type):
public_eps = (self.keystone.
service_catalog.get_endpoints(endpoint_type='publicURL'))
for entry in public_eps[svc_type]:
entry = self._normalize_catalog_entry(entry)
self.endpoints[svc_type] = \
self._build_endpoint_services(entry['url'], svc_type)
# << fix bug/1358215