Getting Started

First, make sure you have the DSE driver properly installed.

Upgrading Existing Code from Core Driver

Minimal Property Settings

Upgrading from cassandra-driver to python-driver-dse can be as simple as changing the Cluster import to the dse package:

from cassandra.cluster import Cluster

cluster = Cluster()
session = cluster.connect()
print session.execute("SELECT release_version FROM system.local")[0]

…becomes:

from dse.cluster import Cluster

cluster = Cluster()
session = cluster.connect()
print session.execute("SELECT release_version FROM system.local")[0]

Changes in Execution Property Defaults

The DSE Driver takes advantage of configuration profiles to allow different execution configurations for the various query handlers. Please see the Execution Profile documentation for a more generalized discussion of the API. What follows here is an upgrade guide for DSE driver, which uses this API. Using this API disallows use of the legacy config parameters, so changes must be made when setting non-default options for any of these parameters:

• Cluster.load_balancing_policy

• Cluster.retry_policy

• Session.default_timeout

• Session.default_consistency_level

• Session.default_serial_consistency_level

• Session.row_factory

For example:

from cassandra.cluster import Cluster
from cassandra.query import tuple_factory

cluster = Cluster()
session = cluster.connect()
session.row_factory = tuple_factory

print session.execute("SELECT release_version FROM system.local")[0]

Here we are only setting one of these attributes, so we use the default profile and change that one attribute:

from cassandra.cluster import ExecutionProfile, EXEC_PROFILE_DEFAULT
from cassandra.query import tuple_factory
from dse.cluster import Cluster

profile = ExecutionProfile(row_factory=tuple_factory)
cluster = Cluster(execution_profiles={EXEC_PROFILE_DEFAULT: profile})
session = cluster.connect()

print session.execute("SELECT release_version FROM system.local")[0]

Profiles are passed in by execution_profile dict.

Here we have more default execution parameters being set:

from cassandra import ConsistencyLevel
from cassandra.cluster import Cluster
from cassandra.policies import WhiteListRoundRobinPolicy, DowngradingConsistencyRetryPolicy
from cassandra.query import tuple_factory

cluster = Cluster(load_balancing_policy=WhiteListRoundRobinPolicy(['127.0.0.1']),
                  default_retry_policy=DowngradingConsistencyRetryPolicy())
session = cluster.connect()
session.default_timeout = 15
session.row_factory = tuple_factory
session.default_consistency_level = ConsistencyLevel.LOCAL_QUORUM
session.default_serial_consistency_level = ConsistencyLevel.LOCAL_SERIAL

print session.execute("SELECT release_version FROM system.local")[0]

In this case we can construct the base ExecutionProfile passing all attributes:

from cassandra import ConsistencyLevel
from cassandra.cluster import ExecutionProfile, EXEC_PROFILE_DEFAULT
from cassandra.policies import WhiteListRoundRobinPolicy, DowngradingConsistencyRetryPolicy
from cassandra.query import tuple_factory
from dse.cluster import Cluster

profile = ExecutionProfile(WhiteListRoundRobinPolicy(['127.0.0.1']),
                           DowngradingConsistencyRetryPolicy(),
                           ConsistencyLevel.LOCAL_QUORUM,
                           ConsistencyLevel.LOCAL_SERIAL,
                           15, tuple_factory)
cluster = Cluster(execution_profiles={EXEC_PROFILE_DEFAULT: profile})
session = cluster.connect()

print session.execute("SELECT release_version FROM system.local")[0]

It should be noted that this sets the default behavior for CQL requests. The DSE driver also defines a set of default profiles for graph execution:

• EXEC_PROFILE_GRAPH_DEFAULT

• EXEC_PROFILE_GRAPH_SYSTEM_DEFAULT

• EXEC_PROFILE_GRAPH_ANALYTICS_DEFAULT

Users are free to setup additional profiles to be used by name:

profile_long = ExecutionProfile(request_timeout=30)
cluster = Cluster(execution_profiles={'long': profile_long})
session = cluster.connect()
session.execute(statement, execution_profile='long')

Also, parameters passed to Session.execute or attached to Statements are still honored as before.

Connecting to DSE

The DSE extension builds on the core DataStax Cassandra Driver. Using the DSE extension is as simple as importing Cluster from the dse package instead of the core cassadnra package:

from dse.cluster import Cluster

cluster = Cluster()
session = cluster.connect()
session.execute("SELECT * FROM system.local")

These types extend the core API, but behave exactly like the core driver counterparts for the purpose of CQL execution (core documentation here).

For examples using the extension with specific DSE features, see the pertinent sections below:

• DSE Authentication

• Graph queries

• Geometric types