Merge "General-host-aggregates part 1."

5 files changed, 134 insertions, 9 deletions

diff --git a/nova/virt/driver.py b/nova/virt/driver.py
index ad73b1896..e29d2d0eb 100644
--- a/nova/virt/driver.py
+++ b/nova/virt/driver.py
@@ -629,12 +629,18 @@ class ComputeDriver(object):
 
     def add_to_aggregate(self, context, aggregate, host, **kwargs):
         """Add a compute host to an aggregate."""
+        #NOTE(jogo) Currently only used for XenAPI-Pool
         raise NotImplementedError()
 
     def remove_from_aggregate(self, context, aggregate, host, **kwargs):
         """Remove a compute host from an aggregate."""
         raise NotImplementedError()
 
+    def undo_aggregate_operation(self, context, op, aggregate_id,
+                                  host, set_error=True):
+        """Undo for  Resource Pools"""
+        raise NotImplementedError()
+
     def get_volume_connector(self, instance):
         """Get connector information for the instance for attaching to volumes.
 
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 39ed81b15..fc710a854 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -2798,6 +2798,20 @@ class LibvirtDriver(driver.ComputeDriver):
             pass
         return output
 
+    def add_to_aggregate(self, context, aggregate, host, **kwargs):
+        """Add a compute host to an aggregate."""
+        #NOTE(jogo) Currently only used for XenAPI-Pool
+        pass
+
+    def remove_from_aggregate(self, context, aggregate, host, **kwargs):
+        """Remove a compute host from an aggregate."""
+        pass
+
+    def undo_aggregate_operation(self, context, op, aggregate_id,
+                                  host, set_error=True):
+        """only used for Resource Pools"""
+        pass
+
 
 class HostState(object):
     """Manages information about the compute node through libvirt"""
diff --git a/nova/virt/xenapi/driver.py b/nova/virt/xenapi/driver.py
index fd2f82106..20d32f8ea 100644
--- a/nova/virt/xenapi/driver.py
+++ b/nova/virt/xenapi/driver.py
@@ -493,6 +493,12 @@ class XenAPIDriver(driver.ComputeDriver):
         return self._pool.remove_from_aggregate(context,
                                                 aggregate, host, **kwargs)
 
+    def undo_aggregate_operation(self, context, op, aggregate_id,
+                                  host, set_error=True):
+        """Undo aggregate operation when pool error raised"""
+        return self._pool.undo_aggregate_operation(context, op,
+                aggregate_id, host, set_error)
+
     def legacy_nwinfo(self):
         """
         Indicate if the driver requires the legacy network_info format.
diff --git a/nova/virt/xenapi/pool.py b/nova/virt/xenapi/pool.py
index 07a03d029..05592f978 100644
--- a/nova/virt/xenapi/pool.py
+++ b/nova/virt/xenapi/pool.py
@@ -21,7 +21,6 @@ Management class for Pool-related functions (join, eject, etc).
 
 import urlparse
 
-from nova.compute import aggregate_states
 from nova import db
 from nova import exception
 from nova import flags
@@ -29,6 +28,7 @@ from nova.openstack.common import cfg
 from nova.openstack.common import jsonutils
 from nova.openstack.common import log as logging
 from nova.openstack.common import rpc
+from nova.virt.xenapi import pool_states
 from nova.virt.xenapi import vm_utils
 
 LOG = logging.getLogger(__name__)
@@ -55,22 +55,58 @@ class ResourcePool(object):
         self._host_uuid = host_rec['uuid']
         self._session = session
 
+    def undo_aggregate_operation(self, context, op, aggregate_id,
+                                  host, set_error):
+        """Undo aggregate operation when pool error raised"""
+        try:
+            if set_error:
+                metadata = {pool_states.KEY: pool_states.ERROR}
+                db.aggregate_metadata_add(context, aggregate_id, metadata)
+            op(context, aggregate_id, host)
+        except Exception:
+            LOG.exception(_('Aggregate %(aggregate_id)s: unrecoverable state '
+                            'during operation on %(host)s') % locals())
+
+    def _is_hv_pool(self, context, aggregate_id):
+        """Checks if aggregate is a hypervisor_pool"""
+        metadata = db.aggregate_metadata_get(context, aggregate_id)
+        return pool_states.POOL_FLAG in metadata.keys()
+
     def add_to_aggregate(self, context, aggregate, host, **kwargs):
         """Add a compute host to an aggregate."""
+        if not self._is_hv_pool(context, aggregate.id):
+            return
+
+        invalid = {pool_states.CHANGING: 'setup in progress',
+                   pool_states.DISMISSED: 'aggregate deleted',
+                   pool_states.ERROR: 'aggregate in error'}
+
+        if (db.aggregate_metadata_get(context, aggregate.id)[pool_states.KEY]
+                in invalid.keys()):
+            raise exception.InvalidAggregateAction(
+                    action='add host',
+                    aggregate_id=aggregate.id,
+                    reason=invalid[db.aggregate_metadata_get(context,
+                            aggregate.id)
+                    [pool_states.KEY]])
+
+        if (db.aggregate_metadata_get(context, aggregate.id)[pool_states.KEY]
+                == pool_states.CREATED):
+            db.aggregate_metadata_add(context, aggregate.id,
+                    {pool_states.KEY: pool_states.CHANGING})
         if len(aggregate.hosts) == 1:
             # this is the first host of the pool -> make it master
             self._init_pool(aggregate.id, aggregate.name)
             # save metadata so that we can find the master again
-            values = {
-                'operational_state': aggregate_states.ACTIVE,
-                'metadata': {'master_compute': host,
-                             host: self._host_uuid},
-                }
-            db.aggregate_update(context, aggregate.id, values)
+            metadata = {'master_compute': host,
+                        host: self._host_uuid,
+                        pool_states.KEY: pool_states.ACTIVE}
+            db.aggregate_metadata_add(context, aggregate.id, metadata)
         else:
             # the pool is already up and running, we need to figure out
             # whether we can serve the request from this host or not.
-            master_compute = aggregate.metadetails['master_compute']
+            master_compute = db.aggregate_metadata_get(context,
+                    aggregate.id)['master_compute']
             if master_compute == FLAGS.host and master_compute != host:
                 # this is the master ->  do a pool-join
                 # To this aim, nova compute on the slave has to go down.
@@ -90,7 +126,22 @@ class ResourcePool(object):
 
     def remove_from_aggregate(self, context, aggregate, host, **kwargs):
         """Remove a compute host from an aggregate."""
-        master_compute = aggregate.metadetails.get('master_compute')
+        if not self._is_hv_pool(context, aggregate.id):
+            return
+
+        invalid = {pool_states.CREATED: 'no hosts to remove',
+                   pool_states.CHANGING: 'setup in progress',
+                   pool_states.DISMISSED: 'aggregate deleted', }
+        if (db.aggregate_metadata_get(context, aggregate.id)[pool_states.KEY]
+                in invalid.keys()):
+            raise exception.InvalidAggregateAction(
+                    action='remove host',
+                    aggregate_id=aggregate.id,
+                    reason=invalid[db.aggregate_metadata_get(context,
+                            aggregate.id)[pool_states.KEY]])
+
+        master_compute = db.aggregate_metadata_get(context,
+                aggregate.id)['master_compute']
         if master_compute == FLAGS.host and master_compute != host:
             # this is the master -> instruct it to eject a host from the pool
             host_uuid = db.aggregate_metadata_get(context, aggregate.id)[host]
diff --git a/nova/virt/xenapi/pool_states.py b/nova/virt/xenapi/pool_states.py
new file mode 100644
index 000000000..5b3765cfc
--- /dev/null
+++ b/nova/virt/xenapi/pool_states.py
@@ -0,0 +1,48 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 OpenStack LLC.
+# 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.
+
+"""Possible states for xen resource pools.
+
+A pool may be 'created', in which case the admin has triggered its
+creation, but the underlying hypervisor pool has not actually being set up
+yet. An pool may be 'changing', meaning that the underlying hypervisor
+pool is being setup. An pool may be 'active', in which case the underlying
+hypervisor pool is up and running. An pool may be 'dismissed' when it has
+no hosts and it has been deleted. An pool may be in 'error' in all other
+cases.
+A 'created' pool becomes 'changing' during the first request of
+adding a host. During a 'changing' status no other requests will be accepted;
+this is to allow the hypervisor layer to instantiate the underlying pool
+without any potential race condition that may incur in master/slave-based
+configurations. The pool goes into the 'active' state when the underlying
+pool has been correctly instantiated.
+All other operations (e.g. add/remove hosts) that succeed will keep the
+pool in the 'active' state. If a number of continuous requests fail,
+an 'active' pool goes into an 'error' state. To recover from such a state,
+admin intervention is required. Currently an error state is irreversible,
+that is, in order to recover from it an pool must be deleted.
+"""
+
+CREATED = 'created'
+CHANGING = 'changing'
+ACTIVE = 'active'
+ERROR = 'error'
+DISMISSED = 'dismissed'
+
+# Metadata keys
+KEY = 'operational_state'
+POOL_FLAG = 'hypervisor_pool'