def connect(seeds, keyspace, datacenter=None, port=9042):
class CustomRetryPolicy(RetryPolicy):
def on_write_timeout(self, query, consistency, write_type,
required_responses, received_responses, retry_num):
# retry at most 5 times regardless of query type
if retry_num >= 5:
return (self.RETHROW, None)
return (self.RETRY, consistency)
load_balancing_policy = None
if datacenter:
# If you are using multiple datacenters it's important to use
# the DCAwareRoundRobinPolicy. If not then the client will
# make cross DC connections. This defaults to round robin
# which means round robin across all nodes irrespective of
# data center.
load_balancing_policy = DCAwareRoundRobinPolicy(local_dc=DATACENTER)
cluster = Cluster(contact_points=seeds,
port=port,
default_retry_policy=CustomRetryPolicy(),
reconnection_policy=ExponentialReconnectionPolicy(1, 60),
load_balancing_policy=load_balancing_policy,
protocol_version=3)
cluster.control_connection_timeout = 10.0
cluster.compression = False
session = cluster.connect(keyspace)
print 'Connection established with %s at port %s' % (seeds, port)
return session
def connect(seeds, keyspace, datacenter=None, port=9042):
from cassandra.io.libevreactor import LibevConnection
from cassandra.cluster import Cluster
from cassandra.policies import DCAwareRoundRobinPolicy, RetryPolicy, ExponentialReconnectionPolicy
class CustomRetryPolicy(RetryPolicy):
def on_write_timeout(self, query, consistency, write_type,
required_responses, received_responses, retry_num):
# retry at most 5 times regardless of query type
if retry_num >= 5:
return (self.RETHROW, None)
return (self.RETRY, consistency)
load_balancing_policy = None
if datacenter:
# If you are using multiple datacenters it's important to use
# the DCAwareRoundRobinPolicy. If not then the client will
# make cross DC connections. This defaults to round robin
# which means round robin across all nodes irrespective of
# data center.
load_balancing_policy = DCAwareRoundRobinPolicy(local_dc=datacenter)
cluster = Cluster(contact_points=seeds,
port=port,
auth_provider=auth_provider,
default_retry_policy=CustomRetryPolicy(),
reconnection_policy=ExponentialReconnectionPolicy(1, 60),
load_balancing_policy=load_balancing_policy)
cluster.connection_class = LibevConnection
cluster.set_core_connections_per_host(0, 3) # local connections
cluster.set_core_connections_per_host(1, 0) # remote connections
cluster.control_connection_timeout = 10.0
cluster.compression = False
session = cluster.connect(keyspace)
return session