MongoDB collection (Cinchy event)

Overview

Data changes in the Cinchy Event Broker (CDC) can be used to trigger a data sync from a MongoDB data source to a specified target. The attributes of the CDC Event are available to use as parameters within the Data Source Definition to narrow the scope of the request. For example, a lookup.

Considerations

Please review the following considerations before you set up your MongoDB Collection data sync source:

• We currently only support SCRAM authentication (Mongo 4.0+).

• Syncs are column based. This means that you must flatten the MongoDB source document prior to sync by using a projection (See section 2: Projection (JSON Object)).

• The column names used in the source must match elements on the root object, except for "$" which can be used to retrieve the full document.

• By default, MongoDB batch size is 101.

• By default, bulk operations size is 5000.

• Due to a conversion of doubles to decimals that occurs during the sync process, minor data losses may occur.

• The following data types aren't supported:

  • Binary Data

  • Regular Expression

  • DBPointer

  • JavaScript

  • JavaScript code with scope

  • Symbol

  • Min Key

  • Max Key

• The following data types are supported with conversions:

  • ObjectID is supported, but converted to string

  • Object is supported, but converted to JSON

  • Array is supported, but converted to JSON

  • Timestamp is supported, but converted to 64-bit integers

Connection definitions

The following sections in the Source configuration of the Connections experience can reference attributes of the CDC Event as parameters:

• Connection String

• Database Name

• Collection Name

• Query

• Projection

• Pipeline

Parameters use the column name or alias as defined in the CDC Event Listener Config prefixed with an @. For example, @CompanyName would be the parameter name for the following Cinchy CDC listener Topic configuration.

{
	"tableGuid": "420c1851-31ed-4ada-a71b-31659bca6f92",
	"fields": [
		{
			"column": "Cinchy Id",
                        "alias":"CinchyId"
                },
		{
			"column": "Company Name",
                        "alias":"CompanyName"
		}
	]
}

The following set of parameters will be available on every event even if they're not present in the listener config

• @Version

• @DraftVersion

• @CinchyRecordType

• @ApprovalState

• @ModifiedBy

• @Modified

• @Deleted

Info tab

You can find the parameters in the Info tab below (Image 1).

Values

Source tab

The following table outlines the mandatory and optional parameters you will find on the Source tab (Image 2).

Query example

// query: where "Price" is less than 10

blog> db.Articles.find({ "Price": { "$lt": 10 } })
[
  {
    _id: ObjectId("63d8137bd755fcdeed234403"),
    Name: 'Shirt',
    Price: 9.95,
    Details: { Color: 'White', Size: 'Small' },
    Stock: 61
  }
]

Projection example

// Flatten the document

blog> db.Articles.find({}, { Name: 1, Price: 1, Color: "Details.Color", Size: "Details.Size", Stock: 1 })
[
  {
    _id: ObjectId("63d812afd755fcdeed234402"),
    Name: 'Shirt',
    Price: 19.95,
    Stock: 12,
    Color: 'Details.Color',
    Size: 'Details.Size'
  },
  {
    _id: ObjectId("63d8137bd755fcdeed234403"),
    Name: 'Shirt',
    Price: 9.95,
    Stock: 61,
    Color: 'Details.Color',
    Size: 'Details.Size'
  }
]

Next steps

• Configure your Destination

• Define your Sync Actions.

• Add in your Post Sync Scripts, if required.

• To run a real-time sync (using the Cinchy Event Triggered MongoDB Source), set up your Listener Config using the Cinchy Event Broker/CDC and enable it to begin your sync.

Appendix A

Data types

The MongoDB Collection Data Source obtains BSON documents from MongoDB. BSON, short for Binary JSON, is a binary-encoded serialization of JSON-like documents. Like JSON, BSON sup­ports the em­bed­ding of doc­u­ments and ar­rays

with­in other documents and arrays. BSON also con­tains extensions that allow representation of data types that aren't part of the JSON spec. For ex­ample BSON makes a distinction between Int32 and Int64.

The following table shows how MongoDB data types are translated in Cinchy.

Listener Config

To configure a MongoDB Collection (Cinchy Event Triggered) connection, a listener must be configured via the Listener Config table with an Event Connector Type of Cinchy CDC.

Review the Cinchy Event Broker/CDC Listener Configuration values here, and then navigate to the Listener Config table to input a new row.

When setting up your listener configuration for your data sync, keeping the following constraints in mind:

• Column names in the listener config shouldn't contain spaces. If they do, they will be automatically removed. For example, a column named Company Name will become the replacement parameter @CompanyName.

• The replacement parameter names are case sensitive.

• Column names in the listener config shouldn't be prefixes of other column names. For example, if you have a column called Name, you shouldn't have another called Name2 as the value of @Name2 may end up being replaced by the value of @Name suffixed with a 2._

Example Listener Configuration

{
  "tableGuid": "420c1851-31ed-4ada-a71b-31659bca6f92",
  "fields": [
    {
      "column": "Cinchy Id",
      "alias": "CinchyId"
    },
    {
      "column": "Company Name",
      "alias": "CompanyName"
    }
  ]
}