Arcion CDC Agent

Real-time replication from SQL Server with Arcion CDC Agent #

For real-time replicaiton from SQL Server, you can choose Arcion CDC Agent as a CDC Extractor. Follow these steps to set up real-time replication using the Arcion CDC Agent.

I. Prerequisites #

Required permissions #

To allow replication, you need to first verify that the necessary permissions are in place on source SQL Server. For more information, see SQL Server User Permissions.

Primary keys on tables #

For full mode replication with Arcion CDC Agent, we recommend that all the tables that you need to replicate have primary keys. If it’s not possible to define primary key on a table, follow the instructions in Replicate tables without primary keys.

II. Set up connection configuration #

Specify the connection details of your SQL Server instance to Replicant in one of the following two ways:

Using a connection configuration file. #

The connection configuration fild holds the connection details and login credentials. You can find a sample connection configuration file sqlserver.yaml in the $REPLICANT_HOME/conf/conn directory. The following configuration parameters are available:

type #

The connection type representing the database. In this case, it’s SQLSERVER.

host #

The hostname of your SQL Server system.

port #

The port number to connect to the host.

username #

The username credential to access the SQL Server system.

password #

The password associated with username.

auth-type #

The authentication protocol for the connection. The following protocols are supported:

  • NATIVE (Default)
  • NLTM

Default authentication protocol is always NATIVE if you don’t explicitly set the auth-type parameter.

In case of NLTM protocol, provide the username in DOMAIN\USER format—for example, domain\alex.

extractor #

The CDC Extractor to use for real-time replication.

To use Arcion CDC Agent, follow these steps:

is_azure #

Optional parameter. If you’re hosting SQL Server on Azure, you must set this parameter to true.

max-connections #

The maximum number of connections Replicant uses to load data into the SQL Server system.

The following is a sample connection configuration:

type: SQLSERVER

host: localhost
port: 1433

username: 'USERNAME'
password: 'PASSWORD'
database: 'tpcc'

extractor: LOG

max-connections: MAX_NUMBER_OF_CONNECTIONS

AWS Secrets Manager #

If you store your connection credentials in AWS Secrets Manager, you can tell Replicant to retrieve them. For more information, see Retrieve credentials from AWS Secrets Manager.

Use KeyStore for credentials #

Replicant supports consuming login credentials from a credentials store. Instead of specifying username and password in plain form, you can keep them in a KeyStore and provide the KeyStore details in the connection configuration file like below:

credentials-store:
    type: {PKCS12|JKS|JCEKS}
    path: PATH_TO_KEYSTORE_FILE
    key-prefix: PREFIX_OF_THE_KEYSTORE_ENTRY
    password: KEYSTORE_PASSWORD

Replace the following:

  • PATH_TO_KEYSTORE_FILE: The path to your KeyStore file.
  • PREFIX_OF_THE_KEYSTORE_ENTRY: The prefix of your KeyStore entries. You can create entries in the credential store using a prefix that preceeds each credential alias. For example, you can create KeyStore entries with aliases sqlserver_username and sqlserver_password. You can then set key-prefix to sqlserver_.
  • KEYSTORE_PASSWORD: The KeyStore password. This parameter is optional. If you don’t want to specify the KeyStore password here, then you must use the UUID from your license file as the KeyStore password. Remember to keep your license file somewhere safe in order to keep the KeyStore password secure.

III. Create the heartbeat table #

For full mode replication, you need to create a heartbeat table. For example:

CREATE TABLE "tpcc"."dbo"."replicate_io_cdc_heartbeat"("timestamp" BIGINT NOT NULL, PRIMARY KEY("timestamp"))

IV. Set up Extractor configuration #

To configure real-time replication according to your requirements, specify your configuration in the Extractor configuration file. You can find a sample sqlserver.yaml in the $REPLICANT_HOME/conf/src directory.

All configuration parameters for realtime mode live under the realtime section. The following is a sample configuration:

realtime:
  threads: 4
  fetch-size-rows: 10000
  fetch-duration-per-extractor-slot-s: 3
  heartbeat:
    enable: true
    catalog: "tpcc"
    schema: "dbo"
    interval-ms: 10000

For more information about the configuration parameters in realtime mode, see Realtime Mode.

Replicate tables without primary keys #

To use Arcion CDC Agent as CDC Extractor, we recommend that all replicated tables have primary keys. However, it’s possible to replicate tables without primary keys if the tables meet the following criteria:

The tables must have a set of non-nullable columns that uniquely identifies each row.

Replicant replicates a table without a primary key by creating a view of that table and then replicating that view instead. By default, each view Replicant creates has the following two properties:

  • Each view belongs to the dbo schema.
  • The name of each view starts with the prefix replicant_.

However, you can change these default properties by specifying the following respective parameters in the SQL Server source connection configuration file:

auxiliary-object-schema #

The name of the schema to which the view belongs to.

auxiliary-object-prefix #

The prefix to use for the name of each view.

For example, the following connection configuration for SQL Server uses the preceeding parameters to set the view properties:

type: SQLSERVER

host: localhost
port: 1433

username: 'alex'
password: 'alex1995'
database: 'tpcc'

extractor: LOG

max-connections: 30

auxiliary-object-schema: 'admin'
auxiliary-object-prefix: 'price_'