Error
Error Code:
1864
MySQL Error 1864: Replication Event Size Exceeded
Description
This error occurs in MySQL replication, specifically with Multi-Threaded Slave (MTS), when a single event from the relay log is too large to be scheduled for execution by a worker thread. It indicates that the event's size has surpassed the configured `replica_pending_jobs_size_max` limit, preventing its processing and potentially halting replication.
Error Message
Cannot schedule event %s, relay-log name %s, position %s to Worker thread because its size %lu exceeds %lu of replica_pending_jobs_size_max.
Known Causes
3 known causesLarge Transaction Event
A single operation on the source server, such as a massive `INSERT` or `UPDATE`, generates a replication event larger than the configured limit on the replica.
Insufficient `replica_pending_jobs_size_max`
The `replica_pending_jobs_size_max` system variable on the replica is set too low, preventing even moderately large events from being processed by worker threads.
Unexpected Workload Spike
An unpredicted surge of large data modifications on the source server produces replication events that exceed the replica's current capacity settings for pending jobs.
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