Debezium Microsoft SQL Server Source

The MSSQL source connector pulls messages from MSSQL and persists the messages to Pulsar topics by using debezium.

Quick start

Prerequisites

The prerequisites for connecting a Debezium MSSQL source connector to external systems include:

Create a MSSQL service: This connector uses the debezium v1.9, Please refer to this document to see the compatible SQL Server versions.
Prepare SQL Server: Please refer to this document to complete the prepare steps.
Enable CDC for SQL Server: Please refer to this document
Enable SQL Server Agent: Please refer to this document

1. Prepare table and permission on SQL Server

Run the following SQL command on Microsoft SQL Server Management Studio:

CREATE DATABASE mydb;
CREATE TABLE MyTable (id INT PRIMARY KEY, name NVARCHAR(50));
GRANT SELECT ON dbo.MyTable TO {{Your hostname of SQL Server}};

Note that we need a primary key for CDC.

2. Create a connector

The following command shows how to use pulsarctl to create a builtin connector. If you want to create a non-builtin connector, you need to replace --source-type debezium-mssql with --archive /path/to/pulsar-io-debezium-mssql.nar. You can find the button to download the nar package at the beginning of the document.

For StreamNative Cloud User

If you are a StreamNative Cloud user, you need set up your environment first.

pulsarctl sources create \
  --source-type debezium-mssql \
  --name debezium-mssql \
  --tenant public \
  --namespace default \
  --parallelism 1 \
  --source-config \
  '{
    "database.hostname": "Your hostname of SQL Server",
    "database.port": "Your port of SQL Server",
    "database.user": "Your user of SQL Server",
    "database.password": "Your password of SQL Server",
    "database.dbname": "Your dbname of SQL Server",
    "table.whitelist": "public.io-test",
    "database.server.name": "mydbserver"
  }'

The --source-config is the minimum necessary configuration for starting this connector, and it is a JSON string. You need to substitute the relevant parameters with your own.

You can set multiple tables for "table.whitelist", and the connector will send data from each table to a different topic of pulsar. The topic naming rule is: "{{database.server.name}}.{{table.name}}". For examples: "public/default/mydbserver.public.io-test".

If you want to configure more parameters, see Configuration Properties for reference.

Note

You can also choose to use a variety of other tools to create a connector:

pulsar-admin: The command arguments for pulsar-admin are similar to those of pulsarctl. You can find an example for StreamNative Cloud Doc.
RestAPI: You can find an example for StreamNative Cloud Doc.
Terraform: You can find an example for StreamNative Cloud Doc.
Function Mesh: The docker image can be found at the beginning of the document.

3. Insert and update a data to table

You can insert and update using the sql:

USE mydb;
INSERT INTO dbo.testtable
           ([id]
           ,[name])
     VALUES (1, 'Zike Yang');
GO

4. Show data using Pulsar client

Note

If your connector is created on StreamNative Cloud, you need to authenticate your clients. See Build applications using Pulsar clients for more information.

bin/pulsar-client \
--url "Your Pulsar serviceUrl" \
consume "persistent://public/default/mssql-test.dbo.testtable" -s "test-sub" -n 0 -p Earliest

----- got message -----
key:[eyJpZCI6MTB9], properties:[], content:{"before":null,"after":{"id":1,"name":"Zike Yang"},"source":{"version":"1.9.7.Final","connector":"sqlserver","name":"mssql-test","ts_ms":1701424975073,"snapshot":"false","db":"mydb","sequence":null,"schema":"dbo","table":"testtable","change_lsn":"00000027:000005a0:0002","commit_lsn":"00000027:000005a0:0003","event_serial_no":1},"op":"c","ts_ms":1701424977325,"transaction":null}

Configuration Properties

The configuration of Debezium source connector has the following properties.

Name	Required	Sensitive	Default	Description
`database.hostname`	true	false	null	The address of a database server.
`database.port`	true	false	null	The port number of a database server.
`database.user`	true	true	null	The name of a database user that has the required privileges.
`database.password`	true	true	null	The password for a database user that has the required privileges.
`database.dbname`	true	false	null	The database.dbname parameter in Debezium configuration is used to specify the name of the specific database that the connector should connect to.
`database.server.name`	true	false	null	The logical name of a database server/cluster, which forms a namespace and it is used in all the names of Kafka topics to which the connector writes, the Kafka Connect schema names, and the namespaces of the corresponding Avro schema when the Avro Connector is used.
`database.server.id`	false	false	null	The connector’s identifier that must be unique within a database cluster and similar to the database’s server-id configuration property.
`database.whitelist`	false	false	null	A list of all databases hosted by this server which is monitored by the connector.<br/><br/> This is optional, and there are other properties for listing databases and tables to include or exclude from monitoring.
`key.converter`	false	false	null	The converter provided by Kafka Connect to convert record key.
`value.converter`	false	false	null	The converter provided by Kafka Connect to convert record value.
`database.history`	false	false	null	The name of the database history class.
`database.history.pulsar.topic`	false	false	null	The name of the database history topic where the connector writes and recovers DDL statements. <br/><br/>Note: this topic is for internal use only and should not be used by consumers.
`database.history.pulsar.service.url`	false	false	null	Pulsar cluster service URL for history topic.
`pulsar.service.url`	false	false	null	Pulsar cluster service URL.
`offset.storage.topic`	false	false	null	Record the last committed offsets that the connector successfully completes.

Advanced features

Converter options

org.apache.kafka.connect.json.JsonConverter
Thejson-with-envelope config is valid only for the JsonConverter. By default, the value is set to false. When the json-with-envelope value is set to false, the consumer uses the schema Schema.KeyValue(Schema.AUTO_CONSUME(), Schema.AUTO_CONSUME(), KeyValueEncodingType.SEPARATED), and the message only consists of the payload. When the json-with-envelope value is set to true, the consumer uses the schema Schema.KeyValue(Schema.BYTES, Schema.BYTES), and the message consists of the schema and the payload.
org.apache.pulsar.kafka.shade.io.confluent.connect.avro.AvroConverter
If you select the AvroConverter, the consumer uses the schema Schema.KeyValue(Schema.AUTO_CONSUME(), Schema.AUTO_CONSUME(), KeyValueEncodingType.SEPARATED), and the message consists of the payload.

Used topic on Pulsar

Currently, the destination topic (specified by the destination-topic-name option ) is a required configuration but it is not used for the Debezium connector to save data. The Debezium connector saves data on the following 4 types of topics:

One topic for storing the database metadata messages. It is named with the database server name ( database.server.name), like public/default/database.server.name.
One topic (offset.storage.topic) for storing the offset metadata messages. The connector saves the last successfully-committed offsets on this topic.
(Option) One topic (database.history.pulsar.topic) for storing the database history information. The connector writes and recovers DDL statements on this topic.
One per-table topic. The connector writes change events for all operations that occur in a table to a single Pulsar topic that is specific to that table. For examples: "public/default/mydbserver.public.io-test" If automatic topic creation is disabled on the Pulsar broker, you need to manually create these 4 types of topics and the destination topic.