MongoDB CDC (Change Data Capture)

Change Data Capture (CDC) streams document-level inserts, updates, and deletes from MongoDB into Weld. Weld consumes the change stream and applies it to your destination with low latency and reliable propagation of updates and deletes.

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Prerequisites

Before enabling CDC in Weld, ensure the following are true in your MongoDB environment:

• Network access: Weld can reach your MongoDB deployment.
• Authentication: A MongoDB user for Weld with the required permissions.
• Collections & identifiers:
  • Identify the databases/collections you plan to replicate.
  • Ensure documents have a stable identifier (MongoDB’s _id typically satisfies this).
• Operational readiness:
  • You have a plan to monitor and maintain CDC-related resources/retention (where applicable).

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🔧 Enable CDC in Weld (once available)

Step 1 — Connect MongoDB in Weld

Create or open your MongoDB connection in Weld.

Step 2 — Choose CDC as the sync mode

Select CDC in the connector settings.

Step 3 — Select collections

Pick the collections to replicate and enable CDC for them.

Step 4 — Configure destination

Choose the destination dataset/schema and naming pattern. Configure apply frequency/latency targets as needed.

Weld will begin consuming change events and applying them to your destination.

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Housekeeping

If you stop or permanently delete a sync, ensure any CDC-related resources created for that sync are cleaned up (where applicable) to avoid unnecessary retention or overhead.