I found meaning of option "router_auto_schedule" is hard to follow. A quick code review finds it is only used at (tests excluded)
```python
def get_router_ids(self, context, host):
"""Returns IDs of routers scheduled to l3 agent on <host>
This will autoschedule unhosted routers to l3 agent on <host> and then
return all ids of routers scheduled to it.
"""
if extensions.is_extension_supported(
self.l3plugin, constants.L3_AGENT_SCHEDULER_EXT_ALIAS):
if cfg.CONF.router_auto_schedule:
self.l3plugin.auto_schedule_routers(context, host)
return self.l3plugin.list_router_ids_on_host(context, host)
```
which seems to be fixing router without agents associated with it. And even if I turn this option off, router is still able to be properly scheduled to agents. because
```python
@registry.receives(resources.ROUTER, [events.AFTER_CREATE],
priority_group.PRIORITY_ROUTER_EXTENDED_ATTRIBUTE)
def _after_router_create(self, resource, event, trigger, context,
router_id, router, router_db, **kwargs):
if not router['ha']:
return
try:
self.schedule_router(context, router_id)
router['ha_vr_id'] = router_db.extra_attributes.ha_vr_id
self._notify_router_updated(context, router_id)
except Exception as e:
with excutils.save_and_reraise_exception() as ctx:
if isinstance(e, l3ha_exc.NoVRIDAvailable):
ctx.reraise = False
LOG.warning("No more VRIDs for router: %s", e)
else:
LOG.exception("Failed to schedule HA router %s.",
router_id)
router['status'] = self._update_router_db(
context, router_id,
{'status': constants.ERROR})['status']
```
seems to not respecting this option.
So IMO auto_schedule_router might better be renamed to something like `fix_dangling_routers` etc and could be turned off if user wants to fix wrong routers manually. The reason is that could router by agent is pretty expensive for a relatively large deployment with around 10,000 routers.
According to the description of that config option, which is "Allow auto scheduling of routers to L3 agent." I'm not sure if it should be responsible only for scheduling broken routers or about scheduling routers to the L3 agents at all.
IMO we should first talk about this in the team meeting before we will decide what we should do next with it.