[Kimchi-devel] [PATCH] host/partitions: avoid calling disks.get_partitions_names() for each partition

In PartitionModel.lookup(), it calls disks.get_partitions_names() to verify the given partition is eligible to be used in a new logical storage pool as follow. if name not in disks.get_partitions_names(): raise NotFoundError(...) When the front-end issues GET request to host/partitions, the back-end would call get_partitions_names() for each partition. If there are many disks and partitions in the host, get_partitions_names() takes a long time to finish, and calling get_partitions_names() for each partition would make the GET request timeout. This patch is to do the following. When the partition is listed from the URI host/partitions, we should avoid calling get_partitions_names() for each of them. When the partition is listed from the URI host/partitions/sdaX, we should verify sdaX is among the eligible partitions. The solution is that we make use of the resource_args in Partitions collection class and override the _get_resources() method. In the _get_resources() method, it sets resource_args to "[True]", indicating that the listed partitions are already verified and eligible, so PartitionModel.lookup() would skip the check. When we are outside of _get_resources() method, resource_args is set to "[False]", and PartitionModel.lookup() enables the check. Signed-off-by: Zhou Zheng Sheng <zhshzhou(a)linux.vnet.ibm.com&gt; --- src/kimchi/control/host.py | 26 +++++++++++++++++++++----- src/kimchi/model/host.py | 4 ++-- 2 files changed, 23 insertions(+), 7 deletions(-) diff --git a/src/kimchi/control/host.py b/src/kimchi/control/host.py index ad34919..11673d5 100644 --- a/src/kimchi/control/host.py +++ b/src/kimchi/control/host.py @@ -17,11 +17,14 @@ # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA +import threading + import cherrypy from kimchi.control.base import Collection, Resource, SimpleCollection from kimchi.control.utils import UrlSubNode, validate_method from kimchi.exception import OperationFailed +from kimchi.rollbackcontext import RollbackContext from kimchi.template import render @@ -75,18 +78,31 @@ class Partitions(Collection): def __init__(self, model): super(Partitions, self).__init__(model) self.resource = Partition + self._reset_resource_args() + self._resource_args_lock = threading.Lock() + + def _reset_resource_args(self): + self.resource_args = [False] - # Defining get_resources in order to return list of partitions in UI - # sorted by their path def _get_resources(self, flag_filter): - res_list = super(Partitions, self)._get_resources(flag_filter) - res_list.sort(key=lambda x: x.info['path']) + with RollbackContext() as rollback: + self._resource_args_lock.acquire() + rollback.prependDefer(self._resource_args_lock.release) + + self.resource_args = [True] + rollback.prependDefer(self._reset_resource_args) + + # Defining get_resources in order to return list of partitions in + # UI sorted by their path + res_list = super(Partitions, self)._get_resources(flag_filter) + res_list.sort(key=lambda x: x.info['path']) return res_list class Partition(Resource): - def __init__(self, model, id): + def __init__(self, model, verified, id): super(Partition, self).__init__(model, id) + self.model_args = [verified] + list(self.model_args) @property def data(self): diff --git a/src/kimchi/model/host.py b/src/kimchi/model/host.py index 47b0aa1..ebd6f79 100644 --- a/src/kimchi/model/host.py +++ b/src/kimchi/model/host.py @@ -244,8 +244,8 @@ class PartitionModel(object): def __init__(self, **kargs): pass - def lookup(self, name): - if name not in disks.get_partitions_names(): + def lookup(self, verified, name): + if not verified and name not in disks.get_partitions_names(): raise NotFoundError("KCHPART0001E", {'name': name}) return disks.get_partition_details(name) -- 1.9.0