Resolving MySQL Deadlock Detected Error

Diagnosis

A deadlock in MySQL occurs when two or more transactions are waiting for each other to release locks, causing a standstill. This is often due to poorly designed queries or transaction management.

Solution

1. Identify the Deadlock: Use MySQL's SHOW ENGINE INNODB STATUS to identify the transactions involved in the deadlock.
2. Analyze Queries: Review the queries and transactions involved to understand the locking behavior.
3. Optimize Transactions: Ensure transactions are as short as possible and access tables in a consistent order.
4. Use Indexes: Ensure proper indexing to avoid full table scans which can lead to deadlocks.
5. Retry Logic: Implement retry logic in your application to handle deadlocks gracefully.

Verification

After implementing the solutions, monitor the system for any recurrence of deadlocks using MySQL logs and performance metrics.