tCassandraInput Standard properties

Property type

Either Built-In or Repository.

Built-In: No property data stored centrally.

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

Use existing connection

Select this check box and in the Component List drop-down list, select the desired connection component to reuse the connection details you already defined.

DB Version

Select the Cassandra version you are using from the drop-down list.

Host

Enter the hostname or IP address of the Cassandra server.

Port

Enter the listening port number of the Cassandra server.

Datacenter

Enter the name of the Cassandra datacenter.

Required authentication

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

This check box appears only if you do not select the Use existing connection check box.

Username

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

This field is only available when you select the Required authentication check box.

Password

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

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

This field is only available when you select the Required authentication check box.

Use SSL

Select this check box to enable the SSL or TLS encrypted connection.

Then you need to use the tSetKeystore component in the same Job to specify the encryption information.

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.

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.

Query

Enter the query statements to be used to read data from the Cassandra database.

By default, the query is not case-sensitive. This means that at runtime, the column names you put in the query are always taken in lower case. If you need to make the query case-sensitive, put the column names in double quotation marks.

The [...] button next to this field allows you to generate the sample code that shows what the pre-defined variables are for the data to be read and how these variables can be used.

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

Global Variables

NB_LINE: the number of rows read by an input component or transferred to an output component. This is an After variable and it returns an integer.

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl+Space to access the variable list and choose the variable to use from it.

For more information about variables, see Using contexts and variables.

Usage rule

This component always needs an output link.