tMongoDBOutput properties for Apache Spark Streaming

Property type

Either Built-In or Repository.

Built-In: No property data stored centrally.

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

MongoDB configuration

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.

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.

If a column in the database is a JSON document and you need to read the entire document, put an asterisk (*) in the DB column column, without quotation marks around.

Collection

Enter the name of the collection to be used.

A MongoDB collection is the equivalent of an RDBMS table and contains documents.

Set write concern

Select this check box to set the level of acknowledgement requested for write operations. Then you need to select the level of this operation.

For further information, see the related MongoDB documentation on http://docs.mongodb.org/manual/core/write-concern/.

Action on data

The following operations are available:

• Insert: insert documents.

• Set: modifies the existing fields of an existing document and appends a field if it does not exist in this document.

  If you need to apply this action on all the documents in the collection to be used, select the Update all document check box that is displayed; otherwise, only the first document is updated.

  If you need to append a new field to a parent node you specify in the Mapping table, select Append to parent. If you leave this check box clear, this new field is appended to the root of the document being updated.

• Upsert with set: inserts a document if it does not exist otherwise it applies the same rules as Set

  If you need to apply this action on all the documents in the collection to be used, select the Update all document check box that is displayed; otherwise, only the first document is updated.

  If you need to append a new field to a parent node you specify in the Mapping table, select Append to parent. If you leave this check box clear, this new field is appended to the root of the document being updated.

Mapping

Each column of the schema defined for this component represents a field of the documents to be read. In this table, you need to specify the parent nodes of these fields, if any.

{
               _id: ObjectId("5099803df3f4948bd2f98391"),
               person: { first: "Joe", last: "Walker" }
            }

Column     Parent node path
_id
first       "person"
last        "person"

Advanced Hadoop MongoDB properties

Add properties to define extra operations you need tMongoDBOutput to perform when writing data.

The available properties are listed and explained in MongoDB Connector for Hadoop.

Usage rule

This component is used as an end component and requires an input link.

This component should use a tMongoDBConfiguration component present in the same Job to connect to a MongoDB database. You need to drop a tMongoDBConfiguration component alongside this component and configure the Basic settings of this component to use tMongoDBConfiguration.

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.