ironic/ironic/common/hash_ring.py
Jim Rollenhagen 3c45f2fd1b Add hardware types to the hash ring
This loads hardware types into the hash ring, along with the drivers
that are currently there. This allows us to make RPC calls for nodes
that are using a dynamic driver.

Adds a dbapi method `get_active_hardware_type_dict`, similar to
`get_active_driver_dict`, to get a mapping of hardware types to active
conductors.

Change-Id: I50c1428568bd8cbe4ef252d56a6278f1a54dfcdb
Partial-Bug: #1524745
2017-01-19 20:35:05 +00:00

71 lines
2.2 KiB
Python

# Copyright 2013 Hewlett-Packard Development Company, L.P.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import threading
import time
from tooz import hashring
from ironic.common import exception
from ironic.common.i18n import _
from ironic.conf import CONF
from ironic.db import api as dbapi
class HashRingManager(object):
_hash_rings = None
_lock = threading.Lock()
def __init__(self):
self.dbapi = dbapi.get_instance()
self.updated_at = time.time()
@property
def ring(self):
interval = CONF.hash_ring_reset_interval
limit = time.time() - interval
# Hot path, no lock
if self.__class__._hash_rings is not None and self.updated_at >= limit:
return self.__class__._hash_rings
with self._lock:
if self.__class__._hash_rings is None or self.updated_at < limit:
rings = self._load_hash_rings()
self.__class__._hash_rings = rings
self.updated_at = time.time()
return self.__class__._hash_rings
def _load_hash_rings(self):
rings = {}
d2c = self.dbapi.get_active_driver_dict()
d2c.update(self.dbapi.get_active_hardware_type_dict())
for driver_name, hosts in d2c.items():
rings[driver_name] = hashring.HashRing(
hosts, partitions=2 ** CONF.hash_partition_exponent)
return rings
@classmethod
def reset(cls):
with cls._lock:
cls._hash_rings = None
def __getitem__(self, driver_name):
try:
return self.ring[driver_name]
except KeyError:
raise exception.DriverNotFound(
_("The driver '%s' is unknown.") % driver_name)