DataStream for mysql read replica database

Google Cloud Database
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1

Hi there,

We are trying to setup DataStream with a read replica (we do not want to generate additional load on the production database). We already activated binary logging, but still get the following error:

“Access denied; you need (at least one of) the SUPER, REPLICATION CLIENT privilege(s) for this operation”

Did someone already create a connection from a replica db to bigquery?

Best
Philipp

2

Absolutely, Philipp! It sounds like you’re encountering a common permissions issue when setting up Datastream with a MySQL read replica. I am not an expert in this product area, however after reviewing some internal resources, here’s a breakdown of what’s happening and how to resolve it:

The Problem

The error “Access denied; you need (at least one of) the SUPER, REPLICATION CLIENT privilege(s) for this operation” means the user account used to connect Datastream to your read replica doesn’t have the necessary permissions. Even though you’ve enabled binary logging, the user still needs specific privileges for replication to work.

The Solution

Identify the Correct User: Determine which user account Datastream is using to connect to the read replica. This should be the account you specified during the Datastream setup.

Grant Privileges: Log in to your MySQL database server (the read replica) with a user account that has sufficient privileges to grant permissions to others. Then, execute the following commands, replacing ‘username’@‘hostname’ with the actual username and hostname of the Datastream connection user:

SQL

GRANT REPLICATION CLIENT ON *.* TO 'username'@'hostname';
GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'username'@'hostname';
FLUSH PRIVILEGES;
  • Explanation:
    • REPLICATION CLIENT: This privilege is essential for any user that will be involved in replication processes.
    • SELECT: Required for the user to read data from the replica.
    • REPLICATION SLAVE: Allows the user to act as a replication slave, which is necessary for Datastream to receive changes from the replica.
    • FLUSH PRIVILEGES: Refreshes the grant tables so the changes take effect immediately.
  1. Test the Connection: After granting the privileges, try setting up the Datastream connection again. The error should be resolved.

Important Considerations:

  • Security: Only grant the minimum necessary privileges to the Datastream user. Avoid granting the SUPER privilege unless absolutely required, as it gives extensive control over the database.
  • Read Replica Setup: Double-check that your read replica is configured correctly and that binary logging is indeed enabled. You can verify this by checking the MySQL configuration files or using the command SHOW MASTER STATUS;.
  • Firewall: Ensure that the MySQL server’s firewall allows incoming connections from the Datastream service. You’ll likely need to open the port used by your MySQL server (usually port 3306).

Additional Tips:

  • Datastream Documentation: Consult Google Cloud’s Datastream documentation for detailed instructions on setting up connections and troubleshooting common issues.
  • Google Cloud Support: If you’re still encountering problems, don’t hesitate to reach out to Google Cloud Support. They can provide assistance tailored to your specific setup.

Let me know if you have any more questions or need further guidance!

3 Likes
3

Hi @pla the error you’re encountering suggests that the MySQL user account used for the DataStream connection doesn’t have the necessary privileges to enable replication or access binary logs on the replica database. Here’s a clear guide to help you resolve this issue:

1. Check and Grant Required Privileges

To connect your read replica to DataStream, the user account needs specific privileges. Please ensure the following:

  • Grant the REPLICATION CLIENT Privilege:
    Run this query in your MySQL instance:

GRANT REPLICATION CLIENT ON . TO ‘your_datastream_user’@‘your_host’;
FLUSH PRIVILEGES;

Replace ‘your_datastream_user’ with the user account name and ‘your_host’ with the IP or hostname of the DataStream service.

  • Additional Privileges (if needed):
    If you still face issues, try adding these privileges:

GRANT SELECT, REPLICATION SLAVE ON . TO ‘your_datastream_user’@‘your_host’;
FLUSH PRIVILEGES;

  • Enable Binary Logging:
    Ensure that binary logging is enabled in your replica database. Check your MySQL configuration file (my.cnf or my.ini) and verify that this parameter is set:

log_bin = ON

2. Verify Replica Settings

For DataStream to work correctly, ensure your replica is configured as follows:

  • Binary Log Format: The binary log format should be set to ROW. Update your MySQL configuration with:

binlog_format = ROW

  • Retention Period: Make sure the binary logs are retained long enough for DataStream to consume them. Configure a suitable retention period like this:

binlog_expire_logs_seconds = 86400 # 1 day, adjust as needed

3. Test the Connection

After updating the privileges and configuration, test the DataStream connection. If the issue persists, consider the following:

  • Error Logs: Check the MySQL server logs for more details.
  • Network Access: Confirm that the DataStream service can connect to your replica database (firewall rules, VPC access, etc.).

4. Simplify Integration with an external tool

If configuring DataStream proves too complex or time-consuming, you might want to explore Windsor.ai as an alternative for replicating data to BigQuery.

  • Why Windsor.ai?

    • Minimal Configuration: Windsor.ai takes care of authentication and replication without requiring extensive privilege setups or binary log configuration.
    • Lightweight: It connects to your read replica, ensuring minimal impact on your production database.
    • Broad Integration: Windsor.ai supports a variety of data sources alongside MySQL.

  • How to Get Started:

    1. Visit Windsor.ai
    2. Set up the MySQL connector and provide your replica database credentials.
    3. Configure BigQuery as your data destination and schedule updates.

This approach can save you time while maintaining reliable data integration.

5. Additional Troubleshooting Tips

If the issue persists with DataStream:

  • Double-Check Permissions: Revisit the user account’s privileges to ensure they align with DataStream requirements.
  • Contact Support: Reach out to Google Cloud support for assistance with specific DataStream errors.
  • Review Logs: Check both MySQL and DataStream logs for any detailed error messages or warnings.

Hope this helps!