This guide shows you how to set up Postgres change data capture (CDC) and stream changes to Azure Event Hubs using Sequin.

With Postgres data streaming to Event Hubs, you can trigger workflows, keep services in sync, build audit logs, maintain caches, and more.

By the end of this how-to, you’ll have database changes flowing to an Event Hub.

This is the how-to guide for streaming Postgres to Azure Event Hubs. See the quickstart for a step-by-step walkthrough or the reference for details on all configuration options.

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Prerequisites

If you’re self-hosting Sequin, you’ll need:

  1. Sequin installed
  2. A database connected
  3. An Azure account

If you’re using Sequin Cloud, you’ll need:

  1. A Sequin Cloud account
  2. A database connected
  3. An Azure account

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Basic setup

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Create an Event Hubs namespace

If you don’t already have an Event Hubs namespace:

  1. Navigate to the Create Event Hubs namespace page in Azure Portal
  2. Fill in the required details:
    • Subscription
    • Resource group
    • Namespace name
    • Location
    • Pricing tier (Basic is fine for getting started)
  3. Click “Review + create”
  4. Click “Create”

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Create an Event Hub

  1. Once your namespace is created, navigate to it in the Azure Portal
  2. Click ”+ Event Hub” at the top
  3. Enter a name for your Event Hub
  4. Leave the default settings or adjust as needed
  5. Click “Create”

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Create a Shared Access Policy

While you can use the default RootManageSharedAccessKey policy, it’s recommended to create a dedicated policy for Sequin:

  1. In your Event Hubs namespace, click “Shared access policies”
  2. Click ”+ Add”
  3. Enter a name (e.g., “sequin-publisher”)
  4. Select only the “Send” permission
  5. Click “Create”
  6. Click on the new policy
  7. Copy either the “Primary key” or “Secondary key”

Make note of your:

  • Event Hubs namespace (e.g., “my-namespace”)
  • Event Hub name (e.g., “postgres-changes”)
  • Shared Access Policy name (e.g., “sequin-publisher”)
  • Shared Access Key

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Create Event Hub sink

In Sequin, navigate to the “Sinks” tab, click “Create Sink”, and select “Azure Event Hub”.

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Configure the source

1

Select source table or schema

Under “Source”, select the table or schema you want to stream data from.

2

Add filters (optional)

Add filters to the sink to control which database changes are sent to your Event Hub.

3

Specify backfill

You can optionally indicate if you want Event Hubs to receive a backfill of all or a portion of the table’s existing data. Backfills are useful if you want to use Event Hubs to process historical data.

You can backfill at any time. If you don’t want to backfill, toggle “Backfill” off.

4

Specify message grouping

Under “Message grouping”, you can specify how messages should be grouped for ordering. Messages in the same group will be delivered in order according to their commit timestamp.

By default, Sequin uses the source row’s primary key(s) for message grouping. You can override this by specifying one or more columns.

Currently, Sequin does not set the partition key when sending messages to Event Hubs. This means that even messages with the same group may be sent to different partitions. If you need partition key support, please upvote the feature request.

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Configure Event Hub

1

Enter Event Hub details

Fill in your Event Hub connection details:

  • Namespace (required): Your Event Hubs namespace (e.g., “my-namespace”)
  • Event Hub Name (required): The name of your Event Hub (e.g., “postgres-changes”)
  • Shared Access Key Name (required): The name of your Shared Access Policy (e.g., “sequin-publisher”)
  • Shared Access Key (required): The primary or secondary key from your Shared Access Policy
2

Test the connection

Click “Test Connection” to verify that Sequin can connect to your Event Hub.

3

Create the sink

Give your sink a name, then click “Create Event Hub Sink”.

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Verify & debug

To verify that your Event Hub sink is working:

  1. Make some changes in your source table
  2. Verify that the count of messages for your sink increases in the Sequin web console
  3. In the Azure Portal:
    • Navigate to your Event Hub
    • Click “Process Data”
    • Select “Data Explorer” in the left sidebar
    • Click “View events”
    • You should see the messages from Sequin appear

If messages don’t seem to be flowing:

  1. Click the “Messages” tab to view the state of messages for your sink
  2. Click any failed message
  3. Check the delivery logs for error details, including any Event Hubs API errors

Common issues to check:

  • Shared Access Key is valid and not expired
  • Shared Access Policy has “Send” permission
  • Namespace and Event Hub name match exactly
  • Event Hub exists in the specified namespace

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Next steps

  • Setup a processor

    Now that your Postgres data is flowing into Event Hubs, you can setup a consumer to read from the Event Hub and process the data. See the Event Hubs documentation for details on consuming events.

  • Deploy your implementation

    When you’re ready to deploy your implementation, see “How to deploy to production”.

  • Advanced configuration

    For more about how Event Hub sinks work, see the Event Hub sink reference.