module Cassandra

Creates a Cluster instance.

Examples:

Connecting to localhost

cluster = Cassandra.cluster

Configuring Cluster

cluster = Cassandra.cluster(
            username: username,
            password: password,
            hosts: ['10.0.1.1', '10.0.1.2', '10.0.1.3']
          )

Parameters:

Name	Type	Details
options	Hash	(defaults to: {}) a customizable set of options

Keys for options:

Key	Type	Details
:hosts	Array<String, IPAddr>	default: ['127.0.0.1'] a list of initial addresses. Note that the entire list of cluster members will be discovered automatically once a connection to any hosts from the original list is successful.
:port	Integer	default: 9042 cassandra native protocol port.
:nodelay	Boolean	default: true when set to true, disables nagle algorithm.
:datacenter	String	default: nil name of current datacenter. First datacenter found will be assumed current by default. Note that you can skip this option if you specify only hosts from the local datacenter in :hosts option.
:shuffle_replicas	Boolean	default: true whether replicas list found by the default Token-Aware Load Balancing Policy should be shuffled. See Token-Aware Load Balancing Policy.
:execution_profiles	Hash<String|Symbol, ExecutionProfile>	default: nil Hash of Execution::Profiles that are available for client use (e.g. Session#execute, Session#execute_async, Session#prepare, and Session#prepare_async).
:connect_timeout	Numeric	default: 10 connection timeout in seconds. Setting value to nil will reset it to 5 seconds.
:timeout	Numeric	default: 12 request execution timeout in seconds. Setting value to nil will remove request timeout.
:heartbeat_interval	Numeric	default: 30 how often should a heartbeat be sent to determine if a connection is alive. Several things to note about this option. Only one heartbeat request will ever be outstanding on a given connection. Each heatbeat will be sent in at least :heartbeat_interval seconds after the last request has been sent on a given connection. Setting value to nil will remove connection timeout.
:idle_timeout	Numeric	default: 60 period of inactivity after which a connection is considered dead. Note that this value should be at least a few times larger than :heartbeat_interval. Setting value to nil will remove automatic connection termination.
:username	String	default: none username to use for authentication to cassandra. Note that you must also specify :password.
:password	String	default: none password to use for authentication to cassandra. Note that you must also specify :username.
:ssl	(Boolean or OpenSSL::SSL::SSLContext)	default: false enable default ssl authentication if true (not recommended). Also accepts an initialized OpenSSL::SSL::SSLContext. Note that this option should be ignored if :server_cert, :client_cert, :private_key or :passphrase are given.
:server_cert	String	default: none path to server certificate or certificate authority file.
:client_cert	String	default: none path to client certificate file. Note that this option is only required when encryption is configured to require client authentication.
:private_key	String	default: none path to client private key. Note that this option is only required when encryption is configured to require client authentication.
:passphrase	String	default: none passphrase for private key.
:compression	Symbol	default: none compression to use. Must be either :snappy or :lz4. Also note, that in order for compression to work, you must install ‘snappy’ or ‘lz4-ruby’ gems.
:load_balancing_policy	LoadBalancing::Policy	default: token aware data center aware round robin.
:address_resolution	Symbol	default: :none a pre-configured address resolver to use. Must be one of :none or :ec2_multi_region.
:connections_per_local_node	Integer	default: nil Number of connections to open to each local node; the value of this option directly correlates to the number of requests the client can make to the local node concurrently. When nil, the setting is 1 for nodes that use the v3 or later protocol, and 2 for nodes that use the v2 or earlier protocol.
:connections_per_remote_node	Integer	default: 1 Number of connections to open to each remote node; the value of this option directly correlates to the number of requests the client can make to the remote node concurrently.
:requests_per_connection	Integer	default: nil Number of outstanding requests to support on one connection. Depending on the types of requests, some may get processed in parallel in the Cassandra node. When nil, the setting is 1024 for nodes that use the v3 or later protocol, and 128 for nodes that use the v2 or earlier protocol.
:protocol_version	Integer	default: nil Version of protocol to speak to nodes. By default, this is auto-negotiated to the highest common protocol version that all nodes in :hosts speak.
:allow_beta_protocol	Boolean	default: false whether the driver should attempt to speak to nodes with a beta version of the newest protocol (which is still under development). USE WITH CAUTION!
:client_timestamps	(Boolean or TimestampGenerator)	default: false whether the driver should send timestamps for each executed statement and possibly which timestamp generator to use. Enabling this setting helps mitigate Cassandra cluster clock skew because the timestamp of the client machine will be used. This does not help mitigate application cluster clock skew. Also accepts an initialized TimestampGenerator, :simple (indicating an instance of TimestampGenerator::Simple), or :monotonic (indicating an instance of TimestampGenerator::TickingOnDuplicate). If set to true, it defaults to TimestampGenerator::Simple for all Ruby flavors except JRuby. On JRuby, it defaults to TimestampGenerator::TickingOnDuplicate.
:synchronize_schema	Boolean	default: true whether the driver should automatically keep schema metadata synchronized. When enabled, the driver updates schema metadata after receiving schema change notifications from Cassandra. Setting this setting to false disables automatic schema updates. Schema metadata is used by the driver to determine cluster partitioners as well as to find partition keys and replicas of prepared statements, this information makes token aware load balancing possible. One can still refresh schema manually.
:schema_refresh_delay	Numeric	default: 1 the driver will wait for :schema_refresh_delay before fetching metadata after receiving a schema change event. This timer is restarted every time a new schema change event is received. Finally, when the timer expires or a maximum wait time of :schema_refresh_timeout has been reached, a schema refresh attempt will be made and the timeout is reset.
:schema_refresh_timeout	Numeric	default: 10 the maximum delay before automatically refreshing schema. Such delay can occur whenever multiple schema change events are continuously arriving within :schema_refresh_delay interval.
:reconnection_policy	Reconnection::Policy	default: Exponential. Note that the default policy is configured with (0.5, 30, 2).
:retry_policy	Retry::Policy	default: Default Retry Policy.
:logger	Logger	default: none logger. a Logger instance from the standard library or any object responding to standard log methods (#debug, #info, #warn, #error and #fatal).
:listeners	Enumerable<Listener>	default: none initial listeners. A list of initial cluster state listeners. Note that a :load_balancing policy is automatically registered with the cluster.
:consistency	Symbol	default: :local_one default consistency to use for all requests. Must be one of CONSISTENCIES.
:trace	Boolean	default: false whether or not to trace all requests by default.
:page_size	Integer	default: 10000 default page size for all select queries. Set this value to nil to disable paging.
:credentials	Hash{String => String}	default: none a hash of credentials - to be used with credentials authentication in cassandra 1.2. Note that if you specified :username and :password options, those credentials are configured automatically.
:auth_provider	Auth::Provider	default: none a custom auth provider to be used with SASL authentication in cassandra 2.0. Note that if you have specified :username and :password, then a Password Provider will be used automatically.
:compressor	Compression::Compressor	default: none a custom compressor. Note that if you have specified :compression, an appropriate compressor will be provided automatically.
:address_resolution_policy	AddressResolution::Policy	default: No Resolution Policy a custom address resolution policy. Note that if you have specified :address_resolution, an appropriate address resolution policy will be provided automatically.
:futures_factory	Object<#all, #error, #value, #promise>	default: Future a futures factory to assist with integration into existing futures library. Note that promises returned by this object must conform to Promise api, which is not yet public. Things may change, use at your own risk.

Returns:

Type	Details
Cluster	a cluster instance

Creates a Cluster instance.

Returns:

Type	Details
Future<Cluster>	a future resolving to the cluster instance.

See Also:

• cluster