Kafka Topic

Overview

Apache Kafka is an end-to-end event streaming platform that:

• Publishes (writes) and subscribes to (reads) streams of events from sources like databases, cloud services, and software applications.

• Stores these events durably and reliably for as long as you want.

• Processes and reacts to the event streams in real-time and retrospectively.

Those events are organized and durably stored in topics. These topics are then partitioned over a number of buckets located on different Kafka brokers.

Event streaming thus ensures a continuous flow and interpretation of data so that the right information is at the right place, at the right time for your key use cases.

Example use case

You currently use Kafka to store the metrics for user logins, but being stuck in the Kafka silo means that you can't easily use this data across a range of business use cases or teams. You can use a batch sync to liberate your data into Cinchy.

The Kafka Topic source supports real-time syncs.

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	Website Metrics
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.	Kafka Topic

LIstener Configuration

To set up a real-time sync, you must configure your Listener values. You can do so through the Connections UI.

Note that If there is more than one listener associated with your data sync, you will need to configure the addition listeners via the Listener Configuration table.

Reset behaviour

Parameter	Description	Example
Auto Offset Reset	Earliest, Latest or None. In the case where the listener is started and either there is no last message ID, or when the last message ID is invalid (due to it being deleted or it's just a new listener), it will use this column as a fallback to determine where to start reading events from. Earliest will start reading from the beginning on the queue (when the CDC was enabled on the table). This might be a suggested configuration if your use case is recoverable or re-runnable and if you need to reprocess all events to ensure accuracy. Latest will fetch the last value after whatever was last processed. This is the typical configuration. None w read or start reading any events. You are able to switch between Auto Offset Reset types after your initial configuration through the process outlined here.	None

Topic JSON

The below table can be used to help create your Topic JSON needed to set up a real-time sync.

Parameter	Description	Example
topicName	Mandatory. This is the Kafka topic name to listen messages on.
messageFormat	Optional. Put "AVRO" if your messages are serialized in AVRO, otherwise leave blank.

Example Topic JSON

{
  "topicName": "<(mandatory) kafka topic name to listen messages on>",
  "messageFormat": "<(optional) Put "AVRO" if the messages are serialized in AVRO>"
}

Connection attributes

The below table can be used to help create your Connection Attributes JSON needed to set up a real-time sync.

Parameter	Description
bootstrapServers	List the Kafka bootstrap servers in a comma-separated list. This should be in the form of host:port
saslMechanism	This will be either PLAIN, SCRAM-SHA-256, or SCRAM-SHA-512. SCRAM-SHA-256 must be formatted as: SCRAMSHA256 SCRAM-SHA-512 must be formatted as: SCRAMSHA512
saslPassword	The password for your chosen SASL mechanism
saslUsername	The username for your chosen SASL mechanism.
url	This is required if your data follows a schema when serialized in AVRO. It's a comma-separated list of URLs for schema registry instances that are used to register or lookup schemas.
basicAuthCredentialsSource	Specifies the Kafka configuration property "schema.registry.basic.auth.credentials.source" that provides the basic authentication credentials. This can be "UserInfo" | "SaslInherit"
basicAuthUserInfo	Basic Auth credentials specified in the form of username:password
sslKeystorePassword	This is the client keystore (PKCS#12) password.
securityProtocol	Kafka supports cluster encryption and authentication, which can encrypt data-in-transit between your applications and Kafka. Use this field to specify which protocol will be used for communication between client and server. Cinchy currently supports the following options: Plaintext, SaslPlaintext, or SaslSsl. Paintext: Unauthenticated, non-encrypted. SaslPlaintext: SASL-based authentication, non-encrypted. SaslSSL: SASL-based authentication, TLS-based encryption. If no parameter is specified, this will default to Plaintext.

{
  "bootstrapServers": "< (mandatory) kafka bootstrap servers in a comma-separated list in the form of host:port>",
  "saslMechanism": "<PLAIN|SCRAM-SHA-256|SCRAM-SHA-512>",
  "saslPassword": "",
  "saslUsername": "",
  "schemaRegistrySettings": {
    "url": "<(optional) This is required if your data follows a schema when serialized in Avro. A comma-separated list of URLs for schema registry instances that are used to register or lookup schemas. >",
   "basicAuthCredentialsSource": "<(optional) Specifies the Kafka configuration property "schema.registry.basic.auth.credentials.source" that provides the basic authentication credentials, this can be "UserInfo" | "SaslInherit">",
   "basicAuthUserInfo": "<(optional) Basic Auth credentials specified in the form of username:password>",
   "sslKeystorePassword": "<(optional) The client keystore (PKCS#12) password>"
  }
  "securityProtocol": "Plaintext | SaslPlaintext | SaslSsl"
}

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.	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.	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

Filter

You have the option to add a source filter to your data sync. Please review the documentation here for more information on source filters.

Image 2: The Source Tab

Next steps

• Configure your Destination
• Define your Sync Actions.
• Add in your Post Sync Scripts, if required.
• If more than one listener is needed for a real-time sync, configure it/them via the Listener Config table.
• To run a real-time sync, enable your Listener from the Execution tab.