# Source: https://neon.com/llms/guides-logical-replication-airbyte.txt

# Replicate data with Airbyte

> The document guides Neon users on setting up data replication from Neon to other destinations using Airbyte, detailing the configuration of sources, destinations, and connections for seamless data transfer.

## Source

- [Replicate data with Airbyte HTML](https://neon.com/docs/guides/logical-replication-airbyte): The original HTML version of this documentation

Neon's logical replication feature allows you to replicate data from your Neon Postgres database to external destinations.

[Airbyte](https://airbyte.com/) is an open-source data integration platform that moves data from a source to a destination system. Airbyte offers a large library of connectors for various data sources and destinations.

In this guide, you will learn how to define your Neon Postgres database as a data source in Airbyte so that you can stream data to one or more of Airbyte's supported destinations.

## Prerequisites

- An [Airbyte account](https://airbyte.com/)
- A [Neon account](https://console.neon.tech/)
- Read the [important notices about logical replication in Neon](https://neon.com/docs/guides/logical-replication-neon#important-notices) before you begin

## Prepare your source Neon database

This section describes how to prepare your source Neon database (the publisher) for replicating data to your destination Neon database (the subscriber).

### Enable logical replication in Neon

   **Important**: Enabling logical replication modifies the Postgres `wal_level` configuration parameter, changing it from `replica` to `logical` for all databases in your Neon project. Once the `wal_level` setting is changed to `logical`, it cannot be reverted. Enabling logical replication also restarts all computes in your Neon project, meaning active connections will be dropped and have to reconnect.

To enable logical replication in Neon:

1. Select your project in the Neon Console.
2. On the Neon **Dashboard**, select **Settings**.
3. Select **Logical Replication**.
4. Click **Enable** to enable logical replication.

You can verify that logical replication is enabled by running the following query from the [Neon SQL Editor](https://neon.com/docs/get-started/query-with-neon-sql-editor):

```sql
SHOW wal_level;
 wal_level
-----------
 logical
```

### Create a Postgres role for replication

It's recommended that you create a dedicated Postgres role for replicating data. The role must have the `REPLICATION` privilege. The default Postgres role created with your Neon project and roles created using the Neon CLI, Console, or API are granted membership in the [neon_superuser](https://neon.com/docs/manage/roles#the-neonsuperuser-role) role, which has the required `REPLICATION` privilege.

Tab: CLI

The following CLI command creates a role. To view the CLI documentation for this command, see [Neon CLI commands — roles](https://api-docs.neon.tech/reference/createprojectbranchrole)

```bash
neon roles create --name replication_user
```

Tab: Console

To create a role in the Neon Console:

1. Navigate to the [Neon Console](https://console.neon.tech).
2. Select a project.
3. Select **Branches**.
4. Select the branch where you want to create the role.
5. Select the **Roles & Databases** tab.
6. Click **Add Role**.
7. In the role creation dialog, specify a role name.
8. Click **Create**. The role is created, and you are provided with the password for the role.

Tab: API

The following Neon API method creates a role. To view the API documentation for this method, refer to the [Neon API reference](https://neon.com/docs/reference/cli-roles).

```bash
curl 'https://console.neon.tech/api/v2/projects/hidden-cell-763301/branches/br-blue-tooth-671580/roles' \
  -H 'Accept: application/json' \
  -H "Authorization: Bearer $NEON_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "role": {
    "name": "replication_user"
  }
}' | jq
```

### Grant schema access to your Postgres role

If your replication role does not own the schemas and tables you are replicating from, make sure to grant access. For example, the following commands grant access to all tables in the `public` schema to Postgres role `replication_user`:

```sql
GRANT USAGE ON SCHEMA public TO replication_user;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO replication_user;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO replication_user;
```

Granting `SELECT ON ALL TABLES IN SCHEMA` instead of naming the specific tables avoids having to add privileges later if you add tables to your publication.

### Create a replication slot

Airbyte requires a dedicated replication slot. Only one source should be configured to use this replication slot.

Airbyte uses the `pgoutput` plugin in Postgres for decoding WAL changes into a logical replication stream. To create a replication slot called `airbyte_slot` that uses the `pgoutput` plugin, run the following command on your database using your replication role:

```sql
SELECT pg_create_logical_replication_slot('airbyte_slot', 'pgoutput');
```

`airbyte_slot` is the name assigned to the replication slot. You will need to provide this name when you set up your Airbyte source.

### Create a publication

Perform the following steps for each table you want to replicate data from:

1. Add the replication identity (the method of distinguishing between rows) for each table you want to replicate:

   ```sql
   ALTER TABLE <table_name> REPLICA IDENTITY DEFAULT;
   ```

   In rare cases, if your tables use data types that support [TOAST](https://www.postgresql.org/docs/current/storage-toast.html) or have very large field values, consider using `REPLICA IDENTITY FULL` instead:

   ```sql
   ALTER TABLE <table_name> REPLICA IDENTITY FULL;
   ```

2. Create the Postgres publication. Include all tables you want to replicate as part of the publication:

   ```sql
   CREATE PUBLICATION airbyte_publication FOR TABLE <tbl1, tbl2, tbl3>;
   ```

   The publication name is customizable. Refer to the [Postgres docs](https://www.postgresql.org/docs/current/logical-replication-publication.html) if you need to add or remove tables from your publication.

   **Note**: The Airbyte UI currently allows selecting any table for Change Data Capture (CDC). If a table is selected that is not part of the publication, it will not be replicated even though it is selected. If a table is part of the publication but does not have a replication identity, the replication identity will be created automatically on the first run if the Postgres role you use with Airbyte has the necessary permissions.

## Create a Postgres source in Airbyte

1. From your Airbyte Cloud account, select **Sources** from the left navigation bar, search for **Postgres**, and then create a new Postgres source.
2. Enter the connection details for your Neon database. You can find your database connection details by clicking the **Connect** button on your **Project Dashboard** to open the **Connect to your database** modal.

      **Important**: Use a **direct connection** to your compute endpoint, not a pooled connection. Logical replication requires a persistent connection and is not compatible with connection poolers. When copying your connection string from Neon, make sure it does not include `-pooler` in the hostname. For more information about connection pooling and when to use direct connections, see [Connection pooling](https://neon.com/docs/connect/connection-pooling).

   For example, given a connection string like this:

   ```bash
   postgresql://alex:AbC123dEf@ep-cool-darkness-123456.us-east-2.aws.neon.tech/dbname?sslmode=require&channel_binding=require
   ```

   Enter the details in the Airbyte **Create a source** dialog as shown below. Your values will differ.
   - **Host**: ep-cool-darkness-123456.us-east-2.aws.neon.tech
   - **Port**: 5432
   - **Database Name**: dbname
   - **Username**: replication_user
   - **Password**: AbC123dEf

3. Under **Optional fields**, list the schemas you want to sync. Schema names are case-sensitive, and multiple schemas may be specified. By default, `public` is the only selected schema.
4. Select an SSL mode. You will most frequently choose `require` or `verify-ca`. Both of these options always require encryption. The `verify-ca` mode requires a certificate. Refer to [Connect securely](https://neon.com/docs/connect/connect-securely) for information about the location of certificate files you can use with Neon.
5. Under **Advanced**:
   - Select **Read Changes using Write-Ahead Log (CDC)** from available replication methods.
   - In the **Replication Slot** field, enter the name of the replication slot you created previously: `airbyte_slot`.
   - In the **Publication** field, enter the name of the publication you created previously: `airbyte_publication`.
     

## Allow inbound traffic

If you are on Airbyte Cloud, and you are using Neon's **IP Allow** feature to limit IP addresses that can connect to Neon, you will need to allow inbound traffic from Airbyte's IP addresses. You can find a list of IPs that need to be allowlisted in the [Airbyte Security docs](https://docs.airbyte.com/operating-airbyte/security). For information about configuring allowed IPs in Neon, see [Configure IP Allow](https://neon.com/docs/manage/projects#configure-ip-allow).

## Complete the source setup

To complete your source setup, click **Set up source** in the Airbyte UI. Airbyte will test the connection to your database. Once this succeeds, you've successfully configured an Airbyte Postgres source for your Neon database.

## Configure a destination

To complete your data integration setup, you can now add one of Airbyte's many supported destinations, such as [Snowflake](https://neon.com/docs/guides/logical-replication-airbyte-snowflake), BigQuery, or Kafka, to name a few. After configuring a destination, you'll need to set up a connection between your Neon source database and your chosen destination. Refer to the Airbyte documentation for instructions:

- [Add a destination](https://docs.airbyte.com/using-airbyte/getting-started/add-a-destination)
- [Set up a connection](https://docs.airbyte.com/using-airbyte/getting-started/set-up-a-connection)

## References

- [What is an ELT data pipeline?](https://airbyte.com/blog/elt-pipeline)
- [Logical replication - PostgreSQL documentation](https://www.postgresql.org/docs/current/logical-replication.html)
- [Publications - PostgreSQL documentation](https://www.postgresql.org/docs/current/logical-replication-publication.html)