Error
Error Code:
4012
MySQL Error 4012: Replica Monitor Thread Start Failure
Description
This error indicates that MySQL was unable to launch the internal thread responsible for monitoring replica (slave) activities. It typically occurs during MySQL server startup or when attempting to initiate replication, preventing the replica from properly connecting to or tracking the primary.
Error Message
The Replica Monitor thread failed to start.
Known Causes
4 known causesInsufficient System Resources
The server may lack adequate memory or CPU capacity to allocate and start new threads, including the Replica Monitor.
Incorrect Replication Configuration
Misconfigurations in `my.cnf` or `my.ini` related to replication parameters can prevent the monitor thread from initializing correctly.
File System or User Permissions
The MySQL user account might lack the necessary read/write permissions for essential directories or files required to start the thread.
Corrupted Replication Data
Damaged relay logs, master info files, or other replication-specific data can hinder the Replica Monitor thread's successful startup.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service