Microsoft SQL Server CDC Source (Debezium) [Legacy] Connector for Confluent Cloud

Tip

Confluent recommends using version 2 of this connector. For more information, see Microsoft SQL Server CDC Source Connector V2 (Debezium) for Confluent Cloud and Moving from V1 to V2.

The fully-managed Microsoft SQL Server Change Data Capture (CDC) Source (Debezium) [Legacy] connector for Confluent Cloud can obtain a snapshot of the existing data in a SQL Server database and then monitor and record all subsequent row-level changes to that data. The connector supports Avro, JSON Schema, Protobuf, or JSON (schemaless) output data formats. All of the events for each table are recorded in a separate Apache Kafka® topic. The events can then be easily consumed by applications and services.

Note

Features

The SQL Server CDC Source (Debezium) [Legacy] connector provides the following features:

  • Topics created automatically: The connector automatically creates Kafka topics using the naming convention: <database.server.name>.<schemaName>.<tableName>. The topics are created with the properties: topic.creation.default.partitions=1 and topic.creation.default.replication.factor=3. For more information, see Maximum message size.
  • Tables included and Tables excluded: Allows you to set whether a table is or is not monitored for changes. By default, the connector monitors every non-system table.
  • Tasks per connector: Organizations can run multiple connectors with a limit of one task per connector (that is, "tasks.max": "1").
  • Snapshot mode: Allows you to specify the criteria for running a snapshot.
  • Tombstones on delete: Allows to configure whether a tombstone event should be generated after a delete event. Default is true.
  • Database authentication: password authentication.
  • Output formats: The connector supports Avro, JSON Schema, Protobuf, or JSON (schemaless) output Kafka record value format. It supports Avro, JSON Schema, Protobuf, JSON (schemaless), and String output Kafka record key format. Schema Registry must be enabled to use a Schema Registry-based format (for example, Avro, JSON_SR (JSON Schema), or Protobuf). See Schema Registry Enabled Environments for additional information.
  • Incremental snapshot: Supports incremental snapshotting via signaling.

For more information and examples to use with the Confluent Cloud API for Connect, see the Confluent Cloud API for Managed and Custom Connectors section.

Limitations

Be sure to review the following information.

Maximum message size

This connector creates topics automatically. When it creates topics, the internal connector configuration property max.message.bytes is set to the following:

  • Basic cluster: 8 MB
  • Standard cluster: 8 MB
  • Enterprise cluster: 8 MB
  • Dedicated cluster: 20 MB

For more information about Confluent Cloud clusters, see Kafka Cluster Types in Confluent Cloud.

Log retention during snapshot

When launched, the CDC connector creates a snapshot of the existing data in the database to capture the nominated tables. To do this, the connector executes a “SELECT *” statement. Completing the snapshot can take a while if one or more of the nominated tables is very large.

During the snapshot process, the database server must retain redo logs and transaction logs so that when the snapshot is complete, the CDC connector can start processing database changes that have completed since the snapshot process began. These logs are retained in a binary log (binlog) on the database server.

If one or more of the tables are very large, the snapshot process could run longer than the binlog retention time set on the database server (that is, expire_logs_days = <number-of-days>). To capture very large tables, you should temporarily retain the binlog for longer than normal by increasing the expire_logs_days number.

Quick Start

Use this quick start to get up and running with the Confluent Cloud Microsoft SQL Server CDC Source (Debezium) [Legacy] connector. The quick start provides the basics of selecting the connector and configuring it to obtain a snapshot of the existing data in a Microsoft SQL Server database and then monitoring and recording all subsequent row-level changes.

Prerequisites
  • Kafka cluster credentials. The following lists the different ways you can provide credentials.
    • Enter an existing service account resource ID.
    • Create a Confluent Cloud service account for the connector. Make sure to review the ACL entries required in the service account documentation. Some connectors have specific ACL requirements.
    • Create a Confluent Cloud API key and secret. To create a key and secret, you can use confluent api-key create or you can autogenerate the API key and secret directly in the Cloud Console when setting up the connector.

Using the Confluent Cloud Console

Step 1: Launch your Confluent Cloud cluster

See the Quick Start for Confluent Cloud for installation instructions.

Step 2: Add a connector

In the left navigation menu, click Connectors. If you already have connectors in your cluster, click + Add connector.

Step 3: Select your connector

Click the Microsoft SQL Server CDC Source (Debezium) [Legacy] connector card.

Microsoft SQL Server CDC Source Connector Card

Step 4: Enter the connector details

Note

  • Make sure you have all your prerequisites completed.
  • An asterisk ( * ) designates a required entry.

At the Microsoft SQL Server CDC Source (Debezium) [Legacy] screen, complete the following:

  1. Select the way you want to provide Kafka Cluster credentials. You can choose one of the following options:
    • My account: This setting allows your connector to globally access everything that you have access to. With a user account, the connector uses an API key and secret to access the Kafka cluster. This option is not recommended for production.
    • Service account: This setting limits the access for your connector by using a service account. This option is recommended for production.
    • Use an existing API key: This setting allows you to specify an API key and a secret pair. You can use an existing pair or create a new one. This method is not recommended for production environments.
  2. Click Continue.

Step 5: Check the Kafka topic

After the connector is running, verify that messages are populating your Kafka topic.

Note

A topic named dbhistory.<database.server.name>.<connect-id> is automatically created for database.history.kafka.topic with one partition.

For more information and examples to use with the Confluent Cloud API for Connect, see the Confluent Cloud API for Managed and Custom Connectors section.

Using the Confluent CLI

Complete the following steps to set up and run the connector using the Confluent CLI.

Note

Make sure you have all your prerequisites completed.

Step 1: List the available connectors

Enter the following command to list available connectors:

confluent connect plugin list

Step 2: List the connector configuration properties

Enter the following command to show the connector configuration properties:

confluent connect plugin describe <connector-plugin-name>

The command output shows the required and optional configuration properties.

Step 3: Create the connector configuration file

Create a JSON file that contains the connector configuration properties. The following example shows the required connector properties.

{
  "connector.class": "SqlServerCdcSource",
  "name": "SqlServerCdcSourceConnector_0",
  "kafka.auth.mode": "KAFKA_API_KEY",
  "kafka.api.key": "****************",
  "kafka.api.secret": "****************************************************************",
  "database.hostname": "connect-sqlserver-cdc.<host-id>.us-west-2.rds.amazonaws.com",
  "database.port": "1433",
  "database.user": "admin",
  "database.password": "************",
  "database.dbname": "database-name",
  "database.server.name": "sql",
  "table.include.list":"public.passengers",
  "snapshot.mode": "initial",
  "output.data.format": "JSON",
  "tasks.max": "1"
}

Note the following property definitions:

  • "connector.class": Identifies the connector plugin name.
  • "name": Sets a name for your new connector.

  • "kafka.auth.mode": Identifies the connector authentication mode you want to use. There are two options: SERVICE_ACCOUNT or KAFKA_API_KEY (the default). To use an API key and secret, specify the configuration properties kafka.api.key and kafka.api.secret, as shown in the example configuration (above). To use a service account, specify the Resource ID in the property kafka.service.account.id=<service-account-resource-ID>. To list the available service account resource IDs, use the following command:

    confluent iam service-account list

    For example:

    confluent iam service-account list

   Id     | Resource ID |       Name        |    Description
+---------+-------------+-------------------+-------------------
   123456 | sa-l1r23m   | sa-1              | Service account 1
   789101 | sa-l4d56p   | sa-2              | Service account 2

  • "table.include.list": (Optional) Enter a comma-separated list of fully-qualified table identifiers for the connector to monitor. By default, the connector monitors all non-system tables. A fully-qualified table name is in the form schemaName.tableName.

  • "snapshot.mode": Specifies the criteria for performing a database snapshot when the connector starts.

    • The default setting is initial. When selected, the connector takes a snapshot of the structure and data from captured tables. This is useful if you want the topics populated with a complete representation of captured table data when the connector starts.
    • Setting this to schema.only takes a snapshot of the structure of the captured tables only. Useful if you want to only capture changes to data that happen from when the connector is started.

  • "output.data.format": Sets the output Kafka record value format (data coming from the connector). Valid entries are AVRO, JSON_SR, PROTOBUF, or JSON. You must have Confluent Cloud Schema Registry configured if using a schema-based record format (for example, Avro, JSON_SR (JSON Schema), or Protobuf).

  • "after.state.only": (Optional) Defaults to true, which results in the Kafka record having only the record state from change events applied. Enter false to maintain the prior record states after applying the change events.

  • "json.output.decimal.format": (Optional) Defaults to BASE64. Specify the JSON/JSON_SR serialization format for Connect DECIMAL logical type values with two allowed literals:

    • BASE64 to serialize DECIMAL logical types as base64 encoded binary data.
    • NUMERIC to serialize Connect DECIMAL logical type values in JSON or JSON_SR as a number representing the decimal value.

  • "column.exclude.list": (Optional) A comma-separated list of regular expressions that match the fully-qualified names of columns to exclude from change event record values. Fully-qualified names for columns are in the form databaseName.tableName.columnName.

  • "signal.data.collection": (Optional) Fully-qualified name of the data collection that is used to send signals to the connector. The collection name is of the form databaseName.schemaName.tableName. These signals can be used to perform incremental snapshotting.

  • "tasks.max": Enter the number of tasks in use by the connector. Organizations can run multiple connectors with a limit of one task per connector (that is, "tasks.max": "1").

Single Message Transforms: See the Single Message Transforms (SMT) documentation for details about adding SMTs using the CLI. For additional information about the Debezium SMTs ExtractNewRecordState and EventRouter (Debezium), see Debezium transformations.

See Configuration Properties for all property values and definitions.

Step 4: Load the properties file and create the connector

Enter the following command to load the configuration and start the connector:

confluent connect cluster create --config-file <file-name>.json

For example:

confluent connect cluster create --config-file microsoft-sql-cdc-source.json

Example output:

Created connector SqlServerCdcSourceConnector_0 lcc-ix4dl

Step 5: Check the connector status

Enter the following command to check the connector status:

confluent connect cluster list

Example output:

ID          |            Name                | Status  |  Type
+-----------+--------------------------------+---------+-------+
lcc-ix4dl   | SqlServerCdcSourceConnector_0  | RUNNING | source

Step 6: Check the Kafka topic.

After the connector is running, verify that messages are populating your Kafka topic.

For more information and examples to use with the Confluent Cloud API for Connect, see the Confluent Cloud API for Managed and Custom Connectors section.

Note

A topic named dbhistory.<database.server.name>.<connect-id> is automatically created for database.history.kafka.topic with one partition.

Configuration Properties

Use the following configuration properties with the fully-managed connector. For self-managed connector property definitions and other details, see the connector docs in Self-managed connectors for Confluent Platform.

How should we connect to your data?

name

Sets a name for your connector.

  • Type: string
  • Valid Values: A string at most 64 characters long
  • Importance: high

Kafka Cluster credentials

kafka.auth.mode

Kafka Authentication mode. It can be one of KAFKA_API_KEY or SERVICE_ACCOUNT. It defaults to KAFKA_API_KEY mode.

  • Type: string
  • Default: KAFKA_API_KEY
  • Valid Values: KAFKA_API_KEY, SERVICE_ACCOUNT
  • Importance: high
kafka.api.key

Kafka API Key. Required when kafka.auth.mode==KAFKA_API_KEY.

  • Type: password
  • Importance: high
kafka.service.account.id

The Service Account that will be used to generate the API keys to communicate with Kafka Cluster.

  • Type: string
  • Importance: high
kafka.api.secret

Secret associated with Kafka API key. Required when kafka.auth.mode==KAFKA_API_KEY.

  • Type: password
  • Importance: high

Schema Config

schema.context.name

Add a schema context name. A schema context represents an independent scope in Schema Registry. It is a separate sub-schema tied to topics in different Kafka clusters that share the same Schema Registry instance. If not used, the connector uses the default schema configured for Schema Registry in your Confluent Cloud environment.

  • Type: string
  • Default: default
  • Importance: medium

How should we connect to your database?

database.hostname

The address of the Microsoft SQL Server.

  • Type: string
  • Importance: high
database.port

Port number of the Microsoft SQL Server.

  • Type: int
  • Valid Values: [0,…,65535]
  • Importance: high
database.user

The name of the Microsoft SQL Server user that has the required authorization.

  • Type: string
  • Importance: high
database.password

The password for the Microsoft SQL Server user that has the required authorization.

  • Type: password
  • Importance: high
database.dbname

The name of the Microsoft SQL Server database to connect to.

  • Type: string
  • Importance: high
database.server.name

The logical name of the Microsoft SQL Server cluster. This logical name forms a namespace and is used in all the names of the Kafka topics and the Kafka Connect schema names. The logical name is also used for the namespaces of the corresponding Avro schema, if Avro data format is used. Kafka topics should/will be created with the prefix database.server.name. Only alphanumeric characters, underscores, hyphens and dots are allowed.

  • Type: string
  • Importance: high
database.instance

The name of the Microsoft SQL Server Instance

  • Type: string
  • Importance: medium
database.applicationIntent

You can specify the keyword ApplicationIntent in your connection string. The assignable values are ReadWrite (the default) or ReadOnly

  • Type: string
  • Default: ReadWrite
  • Valid Values: ReadOnly, ReadWrite
  • Importance: medium

Database details

signal.data.collection

Fully-qualified name of the data collection that needs to be used to send signals to the connector. Use the following format to specify the fully-qualified collection name: databaseName.schemaName.tableName

  • Type: string
  • Importance: medium
snapshot.isolation.mode

A mode to control which transaction isolation level is used and how long the connector locks tables that are designated for capture. The snapshot, read_committed and read_uncommitted modes do not prevent other transactions from updating table rows during initial snapshot. The exclusive and repeatable_read modes do prevent concurrent updates.Mode choice also affects data consistency. Only exclusive and snapshot modes guarantee full consistency, that is, initial snapshot and streaming logs constitute a linear history. In case of repeatable_read and read_committed modes, it might happen that, for instance, a record added appears twice - once in initial snapshot and once in streaming phase. Nonetheless, that consistency level should do for data mirroring. For read_uncommitted there are no data consistency guarantees at all (some data might be lost or corrupted).

  • Type: string
  • Default: repeatable_read
  • Valid Values: exclusive, read_committed, read_uncommitted, repeatable_read, snapshot
  • Importance: low
table.include.list

An optional comma-separated list of strings that match fully-qualified table identifiers for tables to be monitored. Any table not included in this config property is excluded from monitoring. Each identifier is in the form schemaName.tableName. By default the connector monitors every non-system table in each monitored schema. May not be used with “Table excluded”.

  • Type: list
  • Importance: medium
table.exclude.list

An optional comma-separated list of strings that match fully-qualified table identifiers for tables to be excluded from monitoring. Any table not included in this config property is monitored. Each identifier is in the form schemaName.tableName. May not be used with “Table included”.

  • Type: list
  • Importance: medium
snapshot.mode

A mode for taking an initial snapshot of the structure and optionally data of captured tables. Once the snapshot is complete, the connector will continue reading change events from the database’s redo logs. The default setting is initial, and takes a snapshot of structure and data of captured tables; useful if topics should be populated with a complete representation of the data from the captured tables. The schema_only option takes a snapshot of the structure of captured tables only; useful if only changes happening from now onwards should be propagated to topics. The initial_only takes a snapshot of structure and data like initial but instead does not transition into streaming changes once the snapshot has completed.

  • Type: string
  • Default: initial
  • Valid Values: initial, initial_only, schema_only
  • Importance: low
datatype.propagate.source.type

A comma-separated list of regular expressions matching the database-specific data type names that adds the data type’s original type and original length as parameters to the corresponding field schemas in the emitted change records.

  • Type: list
  • Importance: low
tombstones.on.delete

Controls whether a tombstone event should be generated after a delete event. When set to true, the delete operations are represented by a delete event and a subsequent tombstone event. When set to false, only a delete event is sent. Emitting the tombstone event (the default behavior) allows Kafka to completely delete all events pertaining to the given key, once the source record got deleted.

  • Type: boolean
  • Default: true
  • Importance: high
column.exclude.list

Regular expressions matching columns to exclude from change events

  • Type: list
  • Importance: medium

Connection details

poll.interval.ms

Positive integer value that specifies the number of milliseconds the connector should wait during each iteration for new change events to appear. Defaults to 1000 milliseconds, or 1 second.

  • Type: int
  • Default: 1000 (1 second)
  • Valid Values: [1,…]
  • Importance: low
max.batch.size

Positive integer value that specifies the maximum size of each batch of events that should be processed during each iteration of this connector.

  • Type: int
  • Default: 1000
  • Valid Values: [1,…,5000]
  • Importance: low
event.processing.failure.handling.mode

Specifies how the connector should react to exceptions during processing of binlog events.

  • Type: string
  • Default: fail
  • Valid Values: fail, skip, warn
  • Importance: low
heartbeat.interval.ms

Controls how frequently the connector sends heartbeat messages to a Kafka topic. The behavior of default value 0 is that the connector does not send heartbeat messages.

  • Type: int
  • Default: 0
  • Valid Values: [0,…]
  • Importance: low
database.history.skip.unparseable.ddl

A Boolean value that specifies whether the connector should ignore malformed or unknown database statements (true), or stop processing so a human can fix the issue (false). Defaults to false. Consider setting this to true to ignore unparseable statements.

  • Type: boolean
  • Default: false
  • Importance: low

Connector details

provide.transaction.metadata

Stores transaction metadata information in a dedicated topic and enables the transaction metadata extraction together with event counting.

  • Type: boolean
  • Default: false
  • Importance: low
decimal.handling.mode

Specifies how DECIMAL and NUMERIC columns should be represented in change events, including: ‘precise’ (the default) uses java.math.BigDecimal to represent values, which are encoded in the change events using a binary representation and Kafka Connect’s ‘org.apache.kafka.connect.data.Decimal’ type; ‘string’ uses string to represent values; ‘double’ represents values using Java’s ‘double’, which may not offer the precision but will be far easier to use in consumers.

  • Type: string
  • Default: precise
  • Valid Values: double, precise, string
  • Importance: medium
binary.handling.mode

Specifies how binary (blob, binary, etc.) columns should be represented in change events, including: ‘bytes’ (the default) represents binary data as byte array; ‘base64’ represents binary data as base64-encoded string; ‘hex’ represents binary data as hex-encoded (base16) string.

  • Type: string
  • Default: bytes
  • Valid Values: base64, bytes, hex
  • Importance: low
time.precision.mode

Time, date, and timestamps can be represented with different kinds of precisions, including: ‘adaptive’ (the default) bases the precision of time, date, and timestamp values on the database column’s precision; ‘adaptive_time_microseconds’ like ‘adaptive’ mode, but TIME fields always use microseconds precision; ‘connect’ always represents time, date, and timestamp values using Kafka Connect’s built-in representations for Time, Date, and Timestamp, which uses millisecond precision regardless of the database columns’ precision.

  • Type: string
  • Default: adaptive
  • Valid Values: adaptive, adaptive_time_microseconds, connect
  • Importance: medium
cleanup.policy

Set the topic cleanup policy

  • Type: string
  • Default: delete
  • Valid Values: compact, delete
  • Importance: medium
database.history.store.only.captured.tables.ddl

A Boolean value that specifies whether the connector records schema structures from all tables in a schema or database, or only from tables that are designated for capture. Defaults to false.

false - During a database snapshot, the connector records the schema data for all non-system tables in the database, including tables that are not designated for capture. It’s best to retain the default setting. If you later decide to capture changes from tables that you did not originally designate for capture, the connector can easily begin to capture data from those tables, because their schema structure is already stored in the schema history topic.

true - During a database snapshot, the connector records the table schemas only for the tables from which Debezium captures change events. If you change the default value, and you later configure the connector to capture data from other tables in the database, the connector lacks the schema information that it requires to capture change events from the tables.

  • Type: boolean
  • Default: false
  • Importance: low

Output messages

output.data.format

Sets the output Kafka record value format. Valid entries are AVRO, JSON_SR, PROTOBUF, or JSON. Note that you need to have Confluent Cloud Schema Registry configured if using a schema-based message format like AVRO, JSON_SR, and PROTOBUF.

  • Type: string
  • Default: JSON
  • Importance: high
output.key.format

Sets the output Kafka record key format. Valid entries are AVRO, JSON_SR, PROTOBUF, STRING or JSON. Note that you need to have Confluent Cloud Schema Registry configured if using a schema-based message format like AVRO, JSON_SR, and PROTOBUF

  • Type: string
  • Default: JSON
  • Valid Values: AVRO, JSON, JSON_SR, PROTOBUF, STRING
  • Importance: high
after.state.only

Controls whether the generated Kafka record should contain only the state after applying change events.

  • Type: boolean
  • Default: true
  • Importance: low
json.output.decimal.format

Specify the JSON/JSON_SR serialization format for Connect DECIMAL logical type values with two allowed literals:

BASE64 to serialize DECIMAL logical types as base64 encoded binary data and

NUMERIC to serialize Connect DECIMAL logical type values in JSON/JSON_SR as a number representing the decimal value.

  • Type: string
  • Default: BASE64
  • Importance: low

Number of tasks for this connector

tasks.max

Maximum number of tasks for the connector.

  • Type: int
  • Valid Values: [1,…,1]
  • Importance: high

Next Steps

For an example that shows fully-managed Confluent Cloud connectors in action with Confluent Cloud ksqlDB, see the Cloud ETL Demo. This example also shows how to use Confluent CLI to manage your resources in Confluent Cloud.

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