MongoDB CDC

Use the MongoDB CDC(Change Data Capture) Connector to get data from MongoDB into Decodable. The MongoDB CDC Connector is powered by Debezium and able to extract and send change events (INSERTS, UPDATES, and DELETES) through Decodable.

If you are looking for instructions on how to send data from Decodable into MongoDB, see MongoDB in the Connect to a data destination chapter.

Overview

Connector name

mongodb-cdc

Type

source

Delivery guarantee

exactly once

Prerequisites

Before you can get data from MongoDB, the following requirements must be met:

  • Your MongoDB instance must be publicly accessible. Decodable uses the username and password provided during connection creation to authenticate to the database.

  • You must have a MongoDB user with privileges changeStream and read.

  • Your MongoDB instance must be configured for change stream replication. See Change Streams in the MongoDB documentation for more information.

Steps

Follow these steps to get data from MongoDB into Decodable. These steps assume that you are using the Decodable web interface. However, if you want to use the Decodable CLI to create the connection, you can refer to the Property Name column for information about what the underlying property names are.

  1. From the Connections page, select MongoDB CDC and complete the following fields.

    UI Field Property Name in the Decodable CLI Description

    Connection Type

    N/A

    Select Source to use this connector to get data into Decodable.

    Hosts

    hosts

    The host name(s) for your database in Standard Connection String Format. If you have a DNS Seed List URL, you must find the underlying MongoDB instance host names and add them here. For example: mongodb-1.tld:27017,mongodb-2.tld:27017:mongodb-3.tld:27017

    If you are using MongoDB Atlas, the list of host names to include can be found in the Overview page for your database.

    Database

    database

    The name of the database containing the collection.

    Collection

    collection

    The name of the collection that you want to capture CDC records from.

    Username

    username

    The username to use to authenticate to MongoDB.

    Password

    password

    The password associated with the username. This must be provided as a secret resource. If you are using the Decodable CLI, run decodable secret list to view available secrets or decodable secret --help for help with creating a new secret.

    Note: For security purposes, Decodable will never display secret values in plaintext. You can manage which users have permissions to create, delete, or modify secrets in the Access Control management view. See Roles, groups, and permissions for more information.

    Copy Existing Data

    copy.existing

    Optional. Set to true to copy existing data from the collection. See Migrating existing collections for more information.

    Defaults to true

    Additional Configuration Options

    connection.options

    Optional. Any additional configuration options needed to connect to the MongoDB cluster. See Connection String Options in the MongoDB documentation for a full list of connection string options.

  2. Select the stream that you’d like to connect to this connector or create a new stream. Then, select Next.

  3. If you decided to create a new stream in the previous step, you must define its schema. Select New Schema to manually enter the fields and field types present or Import Schema if you want to paste the schema in Avro or JSON format.

    1. The stream’s schema must match the schema of the data that you plan on sending through this connection. For information on how MongoDB types map to Decodable types, see Data Type Mappings.

    2. The incoming data must contain a field named _id, and that field must be specified as a primary key. To specify a primary key, you must first explicitly tell Decodable that the type is not null explicitly by entering: <type> NOT NULL. For example: BIGINT NOT NULL.

    3. For more information about Change Data Capture, change streams, or creating a stream, see the following pages:

  4. Select Next when you are finished providing defining the connection’s schema.

  5. Give the newly created connection a Name and Description and select Save.

Data Type Mappings

The following table describes the mapping of Decodable data types to their MongoDB data type counterparts.

Decodable Type MongoDB Type

INT

Int

BIGINT

Long

FLOAT

Long

DOUBLE

Double

DECIMAL

Decimal128

BOOLEAN

Boolean

DATE

Date Timestamp

TIME

Date Timestamp

TIMESTAMP(3)

Date

TIMESTAMP_LTZ(3)

Date

TIMESTAMP(0)

Timestamp

TIMESTAMP_LTZ(0)

Timestamp

STRING

String

STRING

ObjectId

STRING

UUID

STRING

Symbol

STRING

MD5

STRING

JavaScript

STRING

Regex

BYTES

BinData

ROW

Object

ARRAY

Array

ROW<$ref STRING, $id STRING>

DBPointer

(Point) ROW<type STRING, coordinates ARRAY<DOUBLE>></DOUBLE>

GeoJson

(Line) ROW<type STRING, coordinates ARRAY<DOUBLE>></DOUBLE>

GeoJson