Class Cluster

Information and known state of a Cassandra cluster.

This is the main entry point of the driver. A simple example of access to a Cassandra cluster would be: 

Cluster cluster = Cluster.Builder().AddContactPoint("192.168.0.1").Build(); 
Session session = cluster.Connect("db1"); 
foreach (var row in session.Execute("SELECT * FROM table1")) 
    // do something ...

A cluster object maintains a permanent connection to one of the cluster node that it uses solely to maintain information on the state and current topology of the cluster. Using the connection, the driver will discover all the nodes composing the cluster as well as new nodes joining the cluster.

Inheritance
object
Cluster
Implements
Inherited Members
Namespace: Cassandra
Assembly: Cassandra.dll
Syntax
public class Cluster : ICluster, IDisposable

Properties

Configuration

Gets the cluster configuration.

Declaration
public Configuration Configuration { get; }
Property Value
Type Description
Configuration

MaxProtocolVersion

Gets or sets the maximum protocol version used by this driver.

While property value is maintained for backward-compatibility, use SetMaxProtocolVersion(ProtocolVersion) to set the maximum protocol version used by the driver.

Protocol version used can not be higher than MaxSupported.

Declaration
public static int MaxProtocolVersion { get; set; }
Property Value
Type Description
int

Metadata

Gets read-only metadata on the connected cluster.

This includes the know nodes (with their status as seen by the driver) as well as the schema definitions.

This method may trigger the creation of a connection if none has been established yet.

Declaration
public Metadata Metadata { get; }
Property Value
Type Description
Metadata

Methods

AllHosts()

Returns all known hosts of this cluster.

Declaration
public ICollection<Host> AllHosts()
Returns
Type Description
ICollection<Host>

BuildFrom(IInitializer)

Build a new cluster based on the provided initializer.

Note that for building a cluster programmatically, Cluster.NewBuilder provides a slightly less verbose shortcut with NewBuilder#Build.

Also note that that all the contact points provided by initializer must share the same port.

Declaration
public static Cluster BuildFrom(IInitializer initializer)
Parameters
Type Name Description
IInitializer initializer

the Cluster.Initializer to use
Returns
Type Description
Cluster

the newly created Cluster instance

Builder()

Creates a new Cluster.NewBuilder instance.

This is a shortcut for new Cluster.NewBuilder()

.
Declaration
public static Builder Builder()
Returns
Type Description
Builder

the new cluster builder.

Connect()

Creates a new session on this cluster.

Declaration
public ISession Connect()
Returns
Type Description
ISession

Connect(string)

Creates a new session on this cluster and using a keyspace an existing keyspace.

Declaration
public ISession Connect(string keyspace)
Parameters
Type Name Description
string keyspace

Case-sensitive keyspace name to use
Returns
Type Description
ISession

ConnectAndCreateDefaultKeyspaceIfNotExists(Dictionary<string, string>, bool)

Creates new session on this cluster, and sets it to default keyspace. If default keyspace does not exist then it will be created and session will be set to it. Name of default keyspace can be specified during creation of cluster object with Cluster.Builder().WithDefaultKeyspace("keyspace_name") method.

Declaration
public ISession ConnectAndCreateDefaultKeyspaceIfNotExists(Dictionary<string, string> replication = null, bool durableWrites = true)
Parameters
Type Name Description
Dictionary<string, string> replication

Replication property for this keyspace. To set it, refer to the ReplicationStrategies class methods. It is a dictionary of replication property sub-options where key is a sub-option name and value is a value for that sub-option.

Default value is SimpleStrategy with 'replication_factor' = 2
bool durableWrites

Whether to use the commit log for updates on this keyspace. Default is set to true.
Returns
Type Description
ISession

a new session on this cluster set to default keyspace.

ConnectAsync()

Creates a new session on this cluster.

Declaration
public Task<ISession> ConnectAsync()
Returns
Type Description
Task<ISession>

ConnectAsync(string)

Creates a new session on this cluster and using a keyspace an existing keyspace.

Declaration
public Task<ISession> ConnectAsync(string keyspace)
Parameters
Type Name Description
string keyspace

Case-sensitive keyspace name to use
Returns
Type Description
Task<ISession>

Dispose()

Declaration
public void Dispose()

GetHost(IPEndPoint)

Get the host instance for a given Ip address.

Declaration
public Host GetHost(IPEndPoint address)
Parameters
Type Name Description
IPEndPoint address

Ip address of the host
Returns
Type Description
Host

The host or null if not found

GetReplicas(byte[])

Gets a collection of replicas for a given partitionKey. Backward-compatibility only, use GetReplicas(keyspace, partitionKey) instead.

Declaration
public ICollection<Host> GetReplicas(byte[] partitionKey)
Parameters
Type Name Description
byte[] partitionKey

Byte array representing the partition key
Returns
Type Description
ICollection<Host>

GetReplicas(string, byte[])

Gets a collection of replicas for a given partitionKey on a given keyspace

Declaration
public ICollection<Host> GetReplicas(string keyspace, byte[] partitionKey)
Parameters
Type Name Description
string keyspace

Byte array representing the partition key
byte[] partitionKey

Byte array representing the partition key
Returns
Type Description
ICollection<Host>

RefreshSchema(string, string)

Updates keyspace metadata (including token metadata for token aware routing) for a given keyspace or a specific keyspace table. If no keyspace is provided then this method will update the metadata and token map for all the keyspaces of the cluster.

Declaration
public bool RefreshSchema(string keyspace = null, string table = null)
Parameters
Type Name Description
string keyspace
string table
Returns
Type Description
bool

RefreshSchemaAsync(string, string)

Updates keyspace metadata (including token metadata for token aware routing) for a given keyspace or a specific keyspace table. If no keyspace is provided then this method will update the metadata and token map for all the keyspaces of the cluster.

Declaration
public Task<bool> RefreshSchemaAsync(string keyspace = null, string table = null)
Parameters
Type Name Description
string keyspace
string table
Returns
Type Description
Task<bool>

Shutdown(int)

Shutdown this cluster instance. This closes all connections from all the sessions of this * Cluster instance and reclaim all resources used by it.

This method has no effect if the cluster was already shutdown.

Declaration
public void Shutdown(int timeoutMs = -1)
Parameters
Type Name Description
int timeoutMs

ShutdownAsync(int)

Shutdown this cluster instance asynchronously. This closes all connections from all the sessions of this * Cluster instance and reclaim all resources used by it.

This method has no effect if the cluster was already shutdown.

Declaration
public Task ShutdownAsync(int timeoutMs = -1)
Parameters
Type Name Description
int timeoutMs
Returns
Type Description
Task

Events

HostAdded

Event that gets triggered when a new host is added to the cluster

Declaration
public event Action<Host> HostAdded
Event Type
Type Description
Action<Host>

HostRemoved

Event that gets triggered when a host has been removed from the cluster

Declaration
public event Action<Host> HostRemoved
Event Type
Type Description
Action<Host>

Implements