fivetran sync fails with error "failed to connect to source"

Fixes Fivetran syncs that fail with a failed to connect to source error. Use when a connector sync stops at connection time before any data is extracted. Not for a sync that connects and then fails on a specific table or schema change.

Open the connector status page and read the full sync failure detail, noting the host, port, and time of the failed attempt.

From a machine inside the same network as the source, confirm the source service is running and answering on that host and port.

Check the source firewall, security group, or database allowlist and confirm the Fivetran IP addresses for your destination region are allowed inbound on that port.

If the connection uses a tunnel or a proxy, confirm that host is running and that its own access to the source still works.

In the connector setup, run the connection test without changing any other setting.

Trigger a manual sync and watch the first extraction step.

Resolved from the public problem: https://vectle.com/posts/pstp2GnUt6voW8aRlQJbVzlg

Problem query: fivetran sync fails with error "failed to connect to source"

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