deb-ceilometer/ceilometer/compute/discovery.py
Jason Myers 7050d3be10 Instance Caching
This is the work to complete the resource-metadata-caching blueprint.

* Implement an in-memory cache in the compute agent.
* Change compute-agent to populate an in-memory cache.
* Change compute-agent to use the changes-since parameter in the Nova API call .
* Change compute-agent to record the polling timestamp in the cache.
* Change compute-agent to cache the flavor and image metadata as well.

Implements blueprint resource-metadata-caching

Change-Id: I97594e082db6d8e34d9201a7ec5710978e557d6d
Signed-off-by: Jason Myers <jason@jasonamyers.com>
2015-07-29 08:46:32 -05:00

57 lines
1.9 KiB
Python

#
# Copyright 2014 Red Hat, Inc
#
# 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.
from oslo_config import cfg
from oslo_utils import timeutils
from ceilometer.agent import plugin_base
from ceilometer import nova_client
OPTS = [
cfg.BoolOpt('workload_partitioning',
default=False,
help='Enable work-load partitioning, allowing multiple '
'compute agents to be run simultaneously.')
]
cfg.CONF.register_opts(OPTS, group='compute')
class InstanceDiscovery(plugin_base.DiscoveryBase):
def __init__(self):
super(InstanceDiscovery, self).__init__()
self.nova_cli = nova_client.Client()
self.last_run = None
self.instances = {}
def discover(self, manager, param=None):
"""Discover resources to monitor."""
instances = self.nova_cli.instance_get_all_by_host(
cfg.CONF.host, self.last_run)
for instance in instances:
if getattr(instance, 'OS-EXT-STS:vm_state', None) in ['deleted',
'error']:
self.instances.pop(instance.id, None)
else:
self.instances[instance.id] = instance
self.last_run = timeutils.utcnow(True).isoformat()
return self.instances.values()
@property
def group_id(self):
if cfg.CONF.compute.workload_partitioning:
return cfg.CONF.host
else:
return None