def test_get_distance(self):
policy = DCAwareRoundRobinPolicy("dc1", used_hosts_per_remote_dc=0)
host = Host("ip1", SimpleConvictionPolicy)
host.set_location_info("dc1", "rack1")
policy.populate(Mock(), [host])
self.assertEqual(policy.distance(host), HostDistance.LOCAL)
# used_hosts_per_remote_dc is set to 0, so ignore it
remote_host = Host("ip2", SimpleConvictionPolicy)
remote_host.set_location_info("dc2", "rack1")
self.assertEqual(policy.distance(remote_host), HostDistance.IGNORED)
# dc2 isn't registered in the policy's live_hosts dict
policy.used_hosts_per_remote_dc = 1
self.assertEqual(policy.distance(remote_host), HostDistance.IGNORED)
# make sure the policy has both dcs registered
policy.populate(Mock(), [host, remote_host])
self.assertEqual(policy.distance(remote_host), HostDistance.REMOTE)
# since used_hosts_per_remote_dc is set to 1, only the first
# remote host in dc2 will be REMOTE, the rest are IGNORED
second_remote_host = Host("ip3", SimpleConvictionPolicy)
second_remote_host.set_location_info("dc2", "rack1")
policy.populate(Mock(), [host, remote_host, second_remote_host])
distances = set([policy.distance(remote_host), policy.distance(second_remote_host)])
self.assertEqual(distances, set([HostDistance.REMOTE, HostDistance.IGNORED]))
def test_status_updates(self):
hosts = [Host(i, SimpleConvictionPolicy) for i in range(4)]
for h in hosts[:2]:
h.set_location_info("dc1", "rack1")
for h in hosts[2:]:
h.set_location_info("dc2", "rack1")
policy = DCAwareRoundRobinPolicy("dc1", used_hosts_per_remote_dc=1)
policy.populate(Mock(), hosts)
policy.on_down(hosts[0])
policy.on_remove(hosts[2])
new_local_host = Host(4, SimpleConvictionPolicy)
new_local_host.set_location_info("dc1", "rack1")
policy.on_up(new_local_host)
new_remote_host = Host(5, SimpleConvictionPolicy)
new_remote_host.set_location_info("dc9000", "rack1")
policy.on_add(new_remote_host)
# we now have two local hosts and two remote hosts in separate dcs
qplan = list(policy.make_query_plan())
self.assertEqual(set(qplan[:2]), set([hosts[1], new_local_host]))
self.assertEqual(set(qplan[2:]), set([hosts[3], new_remote_host]))
# since we have hosts in dc9000, the distance shouldn't be IGNORED
self.assertEqual(policy.distance(new_remote_host), HostDistance.REMOTE)
policy.on_down(new_local_host)
policy.on_down(hosts[1])
qplan = list(policy.make_query_plan())
self.assertEqual(set(qplan), set([hosts[3], new_remote_host]))
policy.on_down(new_remote_host)
policy.on_down(hosts[3])
qplan = list(policy.make_query_plan())
self.assertEqual(qplan, [])