MySQL CDC Source Configuration

Use this page when MySQL is the source for a CDC workflow.

CDC mode reads changes from the MySQL binary log. It is different from Load mode, which reads tables directly without binlog setup.

If you only need a bounded load, use MySQL Load Mode Guide instead.

For the canonical setup flow, combine this page with:

Check CDC readiness

There are two places in the UI that surface CDC readiness:

Database Overview in Data Explorer — open the database in the sidebar. The CDC readiness card shows whether CDC is enabled along with the current binlog format, row image, and server ID.

Stream wizard — when creating a new stream, the Data Transfer Mode step checks the source automatically. If binlog is not configured for CDC, the Stream (Change Data Capture) option shows a warning and is disabled.

If both show CDC as ready, the source is configured. If not, apply the settings below and restart MySQL.

Required server settings

For a self-managed MySQL instance, add or update these in the MySQL configuration:

[mysqld]
server_id             = 1
log_bin               = mysql-bin
binlog_format         = row
binlog_row_image      = full
binlog_checksum       = none
expire_logs_days      = 3

Setting	Purpose
`server_id`	Unique identifier for replication. Each replica client needs a distinct value.
`log_bin`	Enables the binary log.
`binlog_format`	Must be `ROW` — statement-based or mixed logging is not supported.
`binlog_row_image`	Must be `FULL` — partial row images can miss column values.
`binlog_checksum`	Set to `NONE` to avoid checksum-related parsing issues.
`expire_logs_days`	Binlog retention period. Set high enough that the stream can start before logs are purged. On MySQL 8.0+, use `binlog_expire_logs_seconds` instead.

Restart MySQL after changing these settings.

Required privileges

The CDC user needs SELECT for reading table metadata and REPLICATION CLIENT + REPLICATION SLAVE for consuming the binlog:

GRANT SELECT, REPLICATION CLIENT, REPLICATION SLAVE ON *.* TO 'cdc_user'@'%';
FLUSH PRIVILEGES;

Verify with:

SHOW GRANTS FOR 'cdc_user'@'%';

Use a dedicated CDC user where practical instead of reusing a broad administrative account.

Cloud-hosted MySQL CDC sources

If the source is provider-managed, use the provider page for network and parameter group setup, then return here for the DBConvert Streams-side CDC requirements:

Validation checklist

Test the MySQL connection from the Data Explorer sidebar (right-click → Test connection) or from the connection editor.
Open the database in Data Explorer and check the CDC readiness card — it should show enabled with BINARY LOG: ON, FORMAT: ROW, and ROW IMAGE: FULL.
Run SHOW GRANTS for the CDC user and confirm REPLICATION CLIENT and REPLICATION SLAVE are granted.
Start with a narrow CDC stream (one or two tables) before scaling to a larger scope.

Troubleshooting

Symptom	Likely cause	Fix
Stream fails to start with binlog error	`log_bin` is OFF	Enable binary logging and restart MySQL
Events missing column values	`binlog_row_image` is not `FULL`	Set to `FULL` and restart
Checksum parse errors	`binlog_checksum` is not `NONE`	Set to `NONE` and restart
Permission denied on binlog	CDC user lacks replication privileges	Run the `GRANT` statement above
Stream starts but misses old events	Binlog retention is too short	Increase `expire_logs_days` or `binlog_expire_logs_seconds`
Provider-managed settings not taking effect	Parameter group change pending reboot	Reboot the instance from the cloud console

For background on how binlog-based CDC works — trigger vs query vs binlog methods, their trade-offs, and common production pitfalls — see MySQL Change Data Capture: a practical guide.