Switch scheduler drivers to load based schedulers

Cloud deployed at scale most likely will use these scheduler
drivers because they allow a fairer resource allocation compared
to chance schedulers (which randomly place resources on the hosts).

Because of their importance, it's only wise to test them in
the gate on a continuous basis, so that we do not get surprised
by accidental regressions.

Rather than pushing this down through devstack-gate/project-config
patches, this chance alters the default of the scheduler
drivers, so that users can also pick these up out of the box.

This means that after an upgrade they would observe a change in
the scheduling behavior, if they relied on the default config.

DocImpact
UpgradeImpact

Closes-bug: #1494667

Change-Id: I5927914cb88eff66bc7a045340ff68cb8da95ad6

diff --git a/etc/neutron.conf b/etc/neutron.conf
index 591370f7992320d90ac3eb63d213a20108465adb..77f8d92f4d65b17433c7cdb8da53b1c947a486f2 100644 (file)
--- a/etc/neutron.conf
+++ b/etc/neutron.conf
@@ -190,9 +190,9 @@
 
 # =========== items for agent scheduler extension =============
 # Driver to use for scheduling network to DHCP agent
-# network_scheduler_driver = neutron.scheduler.dhcp_agent_scheduler.ChanceScheduler
+# network_scheduler_driver = neutron.scheduler.dhcp_agent_scheduler.WeightScheduler
 # Driver to use for scheduling router to a default L3 agent
-# router_scheduler_driver = neutron.scheduler.l3_agent_scheduler.ChanceScheduler
+# router_scheduler_driver = neutron.scheduler.l3_agent_scheduler.LeastRoutersScheduler
 # Driver to use for scheduling a loadbalancer pool to an lbaas agent
 # loadbalancer_pool_scheduler_driver = neutron.services.loadbalancer.agent_scheduler.ChanceScheduler
 

diff --git a/neutron/db/agentschedulers_db.py b/neutron/db/agentschedulers_db.py
index 153a420b9c0493e5d63f484cc3de02914c97fd07..591db0d29725dae0dd4b26f7b758701020b2288b 100644 (file)
--- a/neutron/db/agentschedulers_db.py
+++ b/neutron/db/agentschedulers_db.py
@@ -40,7 +40,7 @@ LOG = logging.getLogger(__name__)
 AGENTS_SCHEDULER_OPTS = [
     cfg.StrOpt('network_scheduler_driver',
                default='neutron.scheduler.'
-                       'dhcp_agent_scheduler.ChanceScheduler',
+                       'dhcp_agent_scheduler.WeightScheduler',
                help=_('Driver to use for scheduling network to DHCP agent')),
     cfg.BoolOpt('network_auto_schedule', default=True,
                 help=_('Allow auto scheduling networks to DHCP agent.')),

diff --git a/neutron/db/l3_agentschedulers_db.py b/neutron/db/l3_agentschedulers_db.py
index e5e19040ee5bd8b0588090c739a5056b21b3b016..b09586a9ad6a44a9d30faad7db4b8361d8c1e6fb 100644 (file)
--- a/neutron/db/l3_agentschedulers_db.py
+++ b/neutron/db/l3_agentschedulers_db.py
@@ -42,7 +42,8 @@ LOG = logging.getLogger(__name__)
 
 L3_AGENTS_SCHEDULER_OPTS = [
     cfg.StrOpt('router_scheduler_driver',
-               default='neutron.scheduler.l3_agent_scheduler.ChanceScheduler',
+               default='neutron.scheduler.l3_agent_scheduler.'
+                       'LeastRoutersScheduler',
                help=_('Driver to use for scheduling '
                       'router to a default L3 agent')),
     cfg.BoolOpt('router_auto_schedule', default=True,