Debezium Won't Start? The Whitespace Bug That Stumped Our Client

We recently got a support ticket that looked simple at first. A client's Debezium MySQL connector kept failing at startup. The error pointed to message.key.columns . The config looked reasonable. But nothing worked.

Here's what happened — and how we fixed it without touching the database schema.

The Problem

The client had a MySQL table with a space in its name: dbo.Sourcing Id Master .

They configured the connector like this:

"message.key.columns" : "dbo.Sourcing Id Master:id"

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Connector validation failed immediately. They tried escaping — backslashes, quotes, every combination. Same error every time.

Why Escaping Doesn't Work Here

The problem isn't at runtime. It's at config validation time.

Debezium's validator for message.key.columns requires the fully-qualified table identifier to contain no whitespace. The validator rejects it before the connector even connects to MySQL.…