Property type

Either Built-In or Repository.

Built-In: No property data stored centrally.

Repository: Select the repository file where the
properties are stored.

DB Version

Select the Cassandra version you are using.

Host

Hostname or IP address of the Cassandra server.

Port

Listening port number of the Cassandra server.

Required authentication

Select this check box to provide credentials for the Cassandra
authentication.

Username

Fill in this field with the username for the Cassandra
authentication.

Password

Fill in this field with the password for the Cassandra
authentication.

To enter the password, click the […] button next to the
password field, and then in the pop-up dialog box enter the password between double quotes
and click OK to save the settings.

Schema and
Edit Schema

A schema is a row description. It defines the number of fields
(columns) to be processed and passed on to the next component. When you create a Spark
Job, avoid the reserved word line when naming the
fields.

Click Edit
schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

• View schema: choose this
  option to view the schema only.

• Change to built-in property:
  choose this option to change the schema to Built-in for local changes.

• Update repository connection:
  choose this option to change the schema stored in the repository and decide whether
  to propagate the changes to all the Jobs upon completion. If you just want to
  propagate the changes to the current Job, you can select No upon completion and choose this schema metadata
  again in the Repository Content
  window.

The schema of this component does not support the Object type and the List type.

Keyspace

Type in the name of the keyspace from which you want to read data.

Column family

Type in the name of the column family from which you want to read data.

Query type and
Query

Enter your DB query paying particularly attention to properly
sequence the fields in order to match the schema definition.

The result of the query must contain only records that match join key you need to use in
tMap. In other words, you must use the schema of the
main flow to tMap to construct the SQL statement here in
order to load only the matched records into the lookup flow.

This approach ensures that no redundant records are loaded into memory and outputted to
the component that follows.

Connection pool

In this area, you configure, for each Spark executor, the connection pool used to control
the number of connections that stay open simultaneously. The default values given to the
following connection pool parameters are good enough for most use cases.

• Max total number of connections: enter the maximum number
  of connections (idle or active) that are allowed to stay open simultaneously.

  The default number is 8. If you enter -1, you allow unlimited number of open connections at the same
  time.

• Max waiting time (ms): enter the maximum amount of time
  at the end of which the response to a demand for using a connection should be returned by
  the connection pool. By default, it is -1, that is to say, infinite.

• Min number of idle connections: enter the minimum number
  of idle connections (connections not used) maintained in the connection pool.

• Max number of idle connections: enter the maximum number
  of idle connections (connections not used) maintained in the connection pool.

Evict connections

Select this check box to define criteria to destroy connections in the connection pool. The
following fields are displayed once you have selected it.

• Time between two eviction runs: enter the time interval
  (in milliseconds) at the end of which the component checks the status of the connections and
  destroys the idle ones.

• Min idle time for a connection to be eligible to
  eviction: enter the time interval (in milliseconds) at the end of which the idle
  connections are destroyed.

• Soft min idle time for a connection to be eligible to
  eviction: this parameter works the same way as Min idle
  time for a connection to be eligible to eviction but it keeps the minimum number
  of idle connections, the number you define in the Min number of idle
  connections field.

Usage rule

This component is used as a start component and requires an output link.

This component should use one and only one tCassandraConfiguration component present in the same Job to connect to
Cassandra. More than one tCassandraConfiguration components
present in the same Job fail the execution of the Job.

This component, along with the Spark Streaming component Palette it belongs to, appears
only when you are creating a Spark Streaming Job.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents
only Standard Jobs, that is to say traditional
Talend
data
integration Jobs.

Spark Connection

This connection is effective on a per-Job basis.