Description:

Execute provided Cassandra Query Language (CQL) select query on a Cassandra 1.x or 2.x cluster. Query result may be converted to Avro or JSON format. Streaming is used so arbitrarily large result sets are supported. This processor can be scheduled to run on a timer, or cron expression, using the standard scheduling methods, or it can be triggered by an incoming FlowFile. If it is triggered by an incoming FlowFile, then attributes of that FlowFile will be available when evaluating the select query. FlowFile attribute ‘executecql.row.count’ indicates how many rows were selected.

Tags:

cassandra, cql, select

Properties:

In the list below, the names of required properties appear in bold. Any other properties (not in bold) are considered optional. The table also indicates any default values, whether a property supports the Expression Language Guide, and whether a property is considered “sensitive”, meaning that its value will be encrypted. Before entering a value in a sensitive property, ensure that the nifi.properties file has an entry for the property nifi.sensitive.props.key.

Name	Default Value	Allowable Values	Description
Cassandra Contact Points			Contact points are addresses of Cassandra nodes. The list of contact points should be comma-separated and in hostname:port format. Example node1:port,node2:port,.... The default client port for Cassandra is 9042, but the port(s) must be explicitly specified.
Keyspace			The Cassandra Keyspace to connect to. If no keyspace is specified, the query will need to include the keyspace name before any table reference.
SSL Context Service		Controller Service API: SSLContextService Implementation: StandardSSLContextService	The SSL Context Service used to provide client certificate information for TLS/SSL connections.
Client Auth	REQUIRED	* WANT * REQUIRED * NONE	Client authentication policy when connecting to secure (TLS/SSL) cluster. Possible values are REQUIRED, WANT, NONE. This property is only used when an SSL Context has been defined and enabled.
Username			Username to access the Cassandra cluster
Password			Password to access the Cassandra cluster Sensitive Property: true
Consistency Level	ONE	* ANY * ONE * TWO * THREE * QUORUM * ALL * LOCAL_QUORUM * EACH_QUORUM * SERIAL * LOCAL_SERIAL * LOCAL_ONE	The strategy for how many replicas must respond before results are returned.
Character Set	UTF-8		Specifies the character set of the record data.
CQL select query			CQL select query Supports Expression Language: true
Max Wait Time	0 seconds		The maximum amount of time allowed for a running CQL select query. Must be of format <duration> <TimeUnit> where <duration> is a non-negative integer and TimeUnit is a supported Time Unit, such as: nanos, millis, secs, mins, hrs, days. A value of zero means there is no limit.
Fetch size	0		The number of result rows to be fetched from the result set at a time. Zero is the default and means there is no limit.
Output Format	Avro	* Avro * JSON	The format to which the result rows will be converted. If JSON is selected, the output will contain an object with field 'results' containing an array of result rows. Each row in the array is a map of the named column to its value. For example: { "results": [{"userid":1, "name":"Joe Smith"}]}

Relationships:

Name	Description
retry	A FlowFile is transferred to this relationship if the query cannot be completed but attempting the operation again may succeed.
failure	CQL query execution failed.
success	Successfully created FlowFile from CQL query result set.

Reads Attributes:

None specified.

Writes Attributes:

Name	Description
executecql.row.count	The number of rows returned by the CQL query