openstack/deb-python-cassandra-driver
Code Issues Proposed changes

Add tests for load balancing policies, related fixes

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This commit is contained in:
Tyler Hobbs
2013-04-10 14:11:38 -05:00
parent 294172b0db
commit 5160fbed14
3 changed files with 165 additions and 16 deletions
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34
cassandra/policies.py
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@@ -59,35 +59,37 @@ class RoundRobinPolicy(LoadBalancingPolicy):
class DCAwareRoundRobinPolicy(LoadBalancingPolicy):
def __init__(self, local_dc, used_hosts_per_remote_dc=0):
LoadBalancingPolicy.__init__(self)
self.local_dc = local_dc
self.used_hosts_per_remote_dc = used_hosts_per_remote_dc
self._dc_live_hosts = {}
self._lock = RLock()
def populate(self, cluster, hosts):
for dc, hosts in groupby(hosts, lambda h: h.dc):
self._dc_live_hosts[dc] = set(hosts)
for dc, dc_hosts in groupby(hosts, lambda h: h.datacenter):
self._dc_live_hosts[dc] = set(dc_hosts)
if len(hosts) == 1:
# position is currently only used for local hosts
local_live = self._dc_live_hosts.get(self.local_dc)
if len(local_live) == 1:
self._position = 0
else:
self._position = randint(0, len(hosts) - 1)
self._position = randint(0, len(local_live) - 1)
def distance(self, host):
if host.dc == self.local_dc:
if host.datacenter == self.local_dc:
return HostDistance.LOCAL
if not self.used_hosts_per_remote_dc:
return HostDistance.IGNORE
return HostDistance.IGNORED
else:
dc_hosts = self._dc_live_hosts.get(host.dc)
dc_hosts = self._dc_live_hosts.get(host.datacenter)
if not dc_hosts:
return HostDistance.IGNORE
return HostDistance.IGNORED
if host in list(dc_hosts)[:self.used_hosts_per_remote_dc]:
return HostDistance.REMOTE
else:
return HostDistance.IGNORE
return HostDistance.IGNORED
def make_query_plan(self, query=None):
with self._lock:
@@ -96,7 +98,7 @@ class DCAwareRoundRobinPolicy(LoadBalancingPolicy):
local_live = list(self._dc_live_hosts.get(self.local_dc))
pos %= len(local_live)
for host in islice(cycle(local_live, pos, pos + len(local_live))):
for host in islice(cycle(local_live), pos, pos + len(local_live)):
yield host
for dc, current_dc_hosts in self._dc_live_hosts.iteritems():
@@ -107,16 +109,16 @@ class DCAwareRoundRobinPolicy(LoadBalancingPolicy):
yield host
def on_up(self, host):
self._dc_live_hosts.setdefault(host.dc, set()).add(host)
self._dc_live_hosts.setdefault(host.datacenter, set()).add(host)
def on_down(self, host):
self._dc_live_hosts.setdefault(host.dc, set()).discard(host)
self._dc_live_hosts.setdefault(host.datacenter, set()).discard(host)
def on_add(self, host):
self._dc_live_hosts.setdefault(host.dc, set()).add(host)
self._dc_live_hosts.setdefault(host.datacenter, set()).add(host)
def on_remove(self, host):
self._dc_live_hosts.setdefault(host.dc, set()).discard(host)
self._dc_live_hosts.setdefault(host.datacenter, set()).discard(host)
class SimpleConvictionPolicy(object):
@@ -236,7 +238,7 @@ class FallthroughRetryPolicy(RetryPolicy):
if attempt_num != 0:
return (self.RETHROW, None)
elif write_type in (WriteType.SIMPLE, WriteType.BATCH, WriteType.COUNTER):
return (self.IGNORE, None)
return (self.IGNORED, None)
elif write_type == WriteType.UNLOGGED_BATCH:
return self._pick_consistency(received_responses)
elif write_type == WriteType.BATCH_LOG: