Error
Error Code:
1689
MySQL Error 1689: Lock Wait Aborted
Description
This error indicates that a transaction was waiting for a lock on a database resource, but its wait was terminated because another, often higher-priority, transaction requested an exclusive lock on the same resource. It commonly occurs in highly concurrent environments where multiple operations contend for the same data.
Error Message
Wait on a lock was aborted due to a pending exclusive lock
Known Causes
4 known causesHigh Concurrency and Contention
Many transactions simultaneously attempt to access and modify the same data, leading to frequent conflicts over shared resources.
Long-Running Transactions
Transactions that hold locks for extended periods increase the likelihood of other transactions waiting for those locks and potentially getting aborted.
Inefficient Indexing or Query Design
Poorly optimized queries or missing indexes can cause transactions to acquire broader or longer-held locks than necessary, increasing contention.
Conflicting Exclusive Lock Request
A critical or higher-priority operation requested an exclusive lock on a resource that a current transaction was already waiting on, forcing the wait to terminate.
Solutions
3 solutions available1. Identify and Terminate Long-Running Queries medium
Find and kill the queries holding locks for too long.
1
Connect to your MySQL server using a client like `mysql` or MySQL Workbench.
2
Execute the following SQL query to view active threads and their states. Look for threads in states like 'Locked', 'Waiting for table metadata lock', or 'Sending data' that have been running for an extended period.
SHOW FULL PROCESSLIST;3
Identify the `Id` column of the long-running query that is likely causing the lock. Then, use the `KILL` command to terminate that specific thread. Replace `[thread_id]` with the actual ID.
KILL [thread_id];4
After killing the offending query, the waiting transaction should be able to proceed. You may need to re-run the transaction that received the error.
2. Optimize Transactions and Queries advanced
Reduce the duration of transactions and the scope of locks.
1
Analyze the queries involved in the transactions that are frequently encountering this error. Identify if they are performing large updates, deletions, or selects without proper indexing.
2
Ensure that your tables have appropriate indexes on columns used in `WHERE` clauses, `JOIN` conditions, and `ORDER BY` clauses. This can significantly speed up query execution and reduce lock times.
3
Break down large transactions into smaller, more manageable ones. This reduces the time a lock is held and the likelihood of contention.
4
Avoid performing DDL operations (like `ALTER TABLE`, `DROP TABLE`) during peak hours or while critical transactions are running, as these can acquire strong metadata locks.
5
Consider using more granular locking mechanisms if applicable, such as row-level locking (default for InnoDB) instead of table-level locking. Ensure your `innodb_table_locks` setting is appropriate.
3. Adjust InnoDB Lock Wait Timeout medium
Configure how long InnoDB waits for a lock before aborting.
1
Connect to your MySQL server.
2
Check the current value of `innodb_lock_wait_timeout`. This is the maximum time in seconds that a transaction waits for a lock.
SHOW VARIABLES LIKE 'innodb_lock_wait_timeout';3
If the default value (often 50 seconds) is too short for your application's normal operation, you can increase it. This is a server-wide setting. You can set it temporarily for the current session or permanently in the MySQL configuration file (`my.cnf` or `my.ini`).
SET GLOBAL innodb_lock_wait_timeout = 120; -- Example: set to 120 seconds4
To make this change permanent, edit your MySQL configuration file. Add or modify the `innodb_lock_wait_timeout` line under the `[mysqld]` section. Restart the MySQL server for the change to take effect.
[mysqld]
innodb_lock_wait_timeout = 1205
Note: Increasing this value might mask underlying performance issues and could lead to longer blocking times if a real deadlock or a very long-running query occurs. It's often better to fix the root cause of the long locks.