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.

The MongoDB Collection (Cinchy Event Triggered) Source supports real-time syncs.

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

In Cinchy v5.6+, you can also reference attributes of the CDC Event in Calculated Columns.

Note that syncs making use of this must limit their batch size to 1.

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"
		}
	]
}

Parameter names are case sensitive when used in the Connection configuration. Parameter matching is performed using literal string replacements. Names shouldn't contain spaces (spaces are automatically removed), and should have differing prefixes.

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

Parameter	Description	Example
Title	Mandatory. Input a name for your data sync	MongoDB Cinchy Event to Cinchy
Variables	Optional. Review our documentation on Variables here for more information about this field.
Permissions	Data syncs are role based access systems where you can give specific groups read, write, execute, and/or all of the above with admin access. Inputting at least an Admin Group is mandatory.

Image 1: The Info Tab

Source tab

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

Source Details

The following parameters will help to define your data sync source and how it functions.

Parameter	Description	Example
Source	Mandatory. Select your source from the drop down menu.	MongoDB Collection (Cinchy Event Triggered)
Connection String	Mandatory. This is the encrypted connection string. You can review MongoDB's Connection String guide and parameter descriptions here. Don't include the /[database] in your connection URL. By default services like MongoDB Atlas will automatically include it when copying the connection string. If authenticating against a database other than the admin db, please provide the name of the database associated with the user’s credentials using the authSource parameter.	Example (Default): mongodb+srv://:@ Example (Against different database): mongodb+srv://:@?authSource=
Database	Mandatory. The name of the MongoDB database that contains the collection listed in the "Collection" parameter.	Blog
Collection	Mandatory. The name of your MongoDB collection.	Article
Type	Mandatory. The method for retrieving your data. This will be either: - db.collection.find(): This method is used to select documents in a collection when there is no need to transform (flatten or aggregate) the data. It's used for basic queries where query and projection are sufficient. - db.collection.aggregate(): This method is used when there is a need to transform the data in a collection. It's used for more complex scenarios with single or multi-stages pipelines. In general, you will yield the quickest performance by using the find method, unless you need a specific aggregation operator.
Query (JSON Object)	A query for retrieving your data. This option appears if you have selected db.collection.find().	Example Query
Projection (JSON Object)	This option appears if you have selected db.collection.find(). Syncs are column based. This means that you must flatten the MongoDB source document prior to sync using a projection.	Example Projection
Pipeline (JSON Array of Objects)	An aggregation pipeline consists of one or more stages that process documents. This option appears if you have selected db.collection.aggregate().
Use SSL	This checkbox can be used to define the use of x.509 certificate authentication for your sync. If checked, you will need to input the following values taken from your cert: - SSL Key PEM - SSL Certificate PEM - SSL CLA PEM

Schema

The Schema section is where you define which source columns you want to sync in your connection. You can repeat the values for multiple columns.

Parameter	Description	Example
Name	Mandatory. The name of your column as it appears in the source. This field is case sensitive and preserves spaces.	Name
Alias	Optional. You may choose to use an alias on your column so that it has a different name in the data sync.
Data Type	Mandatory. The data type of the column values. You can review the supported data types and their translations here.	Text
Description	Optional. You may choose to add a description to your column.

Select Show Advanced for more options for the Schema section.

Parameter	Description	Example
Mandatory	If both Mandatory and Validated are checked on a column, then rows where the column is empty are rejected If just Mandatory is checked on a column, then all rows are synced with the execution log status of failed, and the source error of "Mandatory Rule Violation" If just Validated is checked on a column, then all rows are synced.
Validate Data	If both Mandatory and Validated are checked on a column, then rows where the column is empty are rejected If just Validated is checked on a column, then all rows are synced.
Trim Whitespace	Optional if data type = text. For Text data types, you can choose whether to trim the whitespace._
Max Length	Optional if data type = text. You can input a numerical value in this field that represents the maximum length of the data that can be synced in your column. If the value is exceeded, the row will be rejected (you can find this error in the Execution Log).

You can choose to add in a Transformation > String Replacement by inputting the following:

Parameter	Description	Example
Pattern	Mandatory if using a Transformation. The pattern for your string replacement.
Replacement	What you want to replace your pattern with.

Note that you can have more than one String Replacement

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'
  }
]

Image 2: The Source Tab

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.

MongoDB	Cinchy	Notes
Double	Number	Supported
String	Text	Supported
Object	Text (JSON)	Supported
Array	Text (JSON)	Supported
Binary Data	Binary	Unsupported
ObjectId	Text	Supported
Boolean	Bool	Supported
Date	Date	Supported
Null	-	Supported
RegEx	-	Unsupported
JavaScript	-	Unsupported
Timestamp	Number	Supported
32-bit Integer	Number	Supported
64-bit Integer	Number	Supported
Decimal28	Number	Supported
Min Key	-	Unsupported
Max Key	-	Unsupported
-	Geography	Unsupported
-	Geometry	Unsupported

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"
    }
  ]
}