STAR - Mysql - how to check for record locks

That’s a sharp observation — and your timing catching the rdsadmin cleanup process mid-import is telling. Here's what’s likely going on:

🧹 What Is the rdsadmin "cleanup" Process?

In Amazon RDS for MySQL, rdsadmin is a system-level user created by AWS to handle internal maintenance tasks. You can’t modify or use this account directly, but it performs operations that a superuser might do on a standalone MySQL instance.

The "cleanup" process you saw is probably part of:

• Temporary table cleanup

• Connection cache flushing

• Buffer pool or memory management

• Log file rotation or purging

These tasks are triggered automatically based on usage patterns, thresholds, or scheduled maintenance. They’re designed to optimize performance and free up resources, especially when large queries or imports are underway.

🐢 Why Was That One Table Slow?

Here are some likely culprits:

• Indexes: If the table has complex or fragmented indexes, importing can be slower until MySQL optimizes them.

• Triggers or constraints: Any logic tied to inserts (like foreign key checks or triggers) can slow things down.

• Storage engine overhead: If the table uses InnoDB and has a lot of uncommitted transactions or row-level locks, performance can degrade.

• Buffer pool saturation: Large imports can fill up memory buffers, causing MySQL to slow down until cleanup frees space.

• Statistics recalculation: MySQL may pause to update internal stats mid-import, especially if the table is large or recently altered.

⚡ Why Did It Speed Up After Cleanup?

Once the rdsadmin cleanup process ran, it likely:

• Freed up memory or disk I/O bottlenecks

• Cleared stale locks or temp tables

• Flushed caches or optimized internal buffers

That gave your import the breathing room it needed to finish quickly.

If you want to dig deeper, you could:

• Check the MySQL slow query log (if enabled in RDS)

• Run SHOW ENGINE INNODB STATUS before and after imports

• Monitor buffer pool usage and I/O stats during large operations

Want help tuning that table or optimizing the import process further?

You can’t manually run the rdsadmin cleanup process in Amazon RDS for MySQL — it’s an internal maintenance task managed by AWS. Unlike Oracle RDS, which exposes some rdsadmin procedures for DBA tasks, MySQL RDS doesn’t provide direct access to trigger these system-level operations.

That said, here’s what you can do to encourage cleanup-like behavior:

🛠️ Practical Workarounds

• Restart the RDS instance: This can flush caches, reset connections, and trigger internal housekeeping.

• Optimize the table: Run OPTIMIZE TABLE your_table; to defragment and reclaim space.

• Analyze table stats: Use ANALYZE TABLE your_table; to refresh query planner statistics.

• Check for temp tables or locks: Use SHOW ENGINE INNODB STATUS; or SHOW FULL PROCESSLIST; to spot lingering processes.

🔍 Monitor Performance

• Enable Performance Insights in RDS to track query bottlenecks.

• Use CloudWatch metrics to monitor CPU, memory, and IOPS — spikes may correlate with cleanup events.

If you’re consistently seeing performance issues with that one table, we could dig into its schema, indexes, or query patterns. Want to go there next?

To check for table locks in MySQL—especially relevant if you're troubleshooting slow imports into FileMaker—there are a few handy techniques that work even in an Amazon RDS environment:

🔍 View Current Locks

Use the following queries to inspect lock status:

1. Check Active Processes

SHOW FULL PROCESSLIST;

• Reveals active threads, including queries holding or waiting on locks.

• Look for entries with "Locked" in the State column.

2. Inspect InnoDB Engine Status

SHOW ENGINE INNODB STATUS;

• Returns a detailed dump including locking information.

• Search within the output for sections like LATEST DETECTED DEADLOCK or TRANSACTIONS showing lock waits.

3. Analyze Metadata Locks

SELECT * FROM performance_schema.metadata_locks
WHERE LOCK_STATUS = 'PENDING';

• If performance_schema is enabled, this table shows pending metadata locks (e.g. schema-level locks preventing table access).

4. Check Table-Level Lock Info

SELECT 
    object_schema, 
    object_name, 
    lock_type, 
    lock_duration, 
    lock_status 
FROM performance_schema.table_lock_waits;

• Offers insight into which sessions are waiting for locks on specific tables.

⚠️ Important Notes for Amazon RDS:

• Some diagnostics may require enabling performance_schema or modifying parameter group settings.

• You won’t have SUPER privileges, so some commands might return limited info.

• For persistent lock issues, AWS Performance Insights can help highlight queries causing bottlenecks.

If you share the structure of the slow table or its typical usage patterns, I can help pinpoint potential schema-level lock risks or suggest optimizations. Want to take a peek at its indexes or constraints next?