apache/seatunnel · info

MySQL-CDC diagnostic: variable

Error message

MySQL-CDC diagnostic: variable {} not found

What it means

Diagnostic WARN from logMySqlVariable: a SHOW VARIABLES LIKE '<name>' query for a specific MySQL variable (used by logMySqlBinlogRetentionVariables, e.g. binlog_expire_logs_seconds or expire_logs_days) returned no rows, meaning the variable does not exist on this server version. This indicates the retention analysis cannot be based on that variable.

Solutions

  1. Verify which retention variable your MySQL version supports (binlog_expire_logs_seconds for 8.0, expire_logs_days for 5.7) and read it manually
  2. Upgrade SeaTunnel/Debezium connector version if it needs to cover the other variable name
  3. Treat the warning as benign if the counterpart variable was found
Defensive patterns

Strategy: fallback

Validate before calling

SELECT @@version; -- 8.0+: binlog_expire_logs_seconds, 5.7: expire_logs_days
SHOW VARIABLES LIKE 'binlog_expire%';
SHOW VARIABLES LIKE 'expire_logs_days';

Try / catch

try (ResultSet rs = stmt.executeQuery("SHOW VARIABLES LIKE 'binlog_expire_logs_seconds'")) {
    if (!rs.next()) {
        // fallback for MySQL 5.7
        query("SHOW VARIABLES LIKE 'expire_logs_days'");
    }
}

Prevention

When it happens

Trigger: logMySqlBinlogRetentionVariables calls logMySqlVariable for a retention variable and rs.next() is false — typically because the MySQL version names the variable differently (binlog_expire_logs_seconds on 8.0 vs expire_logs_days on 5.7) or the variable was removed.

Common situations: Mixed MySQL 5.7/8.0 environments; Percona/MariaDB variants lacking a variable; checking both names and seeing one 'not found' warning per missing name.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/a6c397893341fd32. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-cdc/connector-cdc-mysql/src/main/java/org/apache/seatunnel/connectors/seatunnel/cdc/mysql/source/reader/fetch/MySqlSourceFetchTaskContext.java:497

                    e.getMessage());
        }
    }

    private void logMySqlBinlogRetentionVariables() {
        logMySqlVariable("log_bin");
        logMySqlVariable("binlog_format");
        logMySqlVariable("binlog_expire_logs_seconds");
        logMySqlVariable("expire_logs_days");
    }

    private void logMySqlVariable(String variableName) {
        final String sql = String.format("SHOW VARIABLES LIKE '%s'", variableName);
        try {
            connection.query(
                    sql,
                    rs -> {
                        if (!rs.next()) {
                            LOG.warn("MySQL-CDC diagnostic: variable {} not found", variableName);
                            return;
                        }
                        LOG.warn(
                                "MySQL-CDC diagnostic: variable {}={}",
                                rs.getString(1),
                                rs.getString(2));
                    });
        } catch (SQLException e) {
            LOG.warn(
                    "MySQL-CDC diagnostic: failed to query variable {}: {}",
                    variableName,
                    e.getMessage());
        }
    }

    private void logMySqlMasterStatus() {
        try {
            connection.query(

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