Details
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Bug
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Status: Needs Feedback (View Workflow)
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Major
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Resolution: Unresolved
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11.8.3
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None
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Related to performance
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Q1/2026 Server Maintenance
Description
Environment:
MariaDB SkySQL - Serverless DB – dbtbf04949730
Server vestion : 11.8.2
While scaling a Serverless instance (dbtbf04949730), a background operation executed
SET GLOBAL innodb_buffer_pool_size=67108864, which triggered a complete system lock.
During the resize, multiple user sessions became blocked on system table locks , and the database became unresponsive for ~6 minutes before the container crashed and restarted.
Both CREATE TABLE statements are blocked by the buffer pool resize.Both CREATE TABLE statements need to write to SYS_TABLES (InnoDB’s data dictionary), but they can’t because the buffer pool resize holds an exclusive lock on it.
Eventually the service crashes and restarts, unblocking operations.
SET GLOBAL innodb_buffer_pool_size=67108864; |
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Observe via SHOW PROCESSLIST:
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| 30053 | skysql_admin | Query | 384s | SET GLOBAL innodb_buffer_pool_size=67108864 | |
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| 30057 | dbtbf04949730 | Query | 384s | CREATE TABLE test123455 (...) | |
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| 30165 | dbtbf04949730 | Query | 244s | CREATE TABLE test_users (...) |
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i
nformation_schema.innodb_locks shows exclusive (X) locks on SYS_TABLES.
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SELECT * FROM information_schema.innodb_locks;
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| lock_id | lock_trx_id | lock_mode | lock_type | lock_table | lock_index | lock_space | lock_page | lock_rec | lock_data |
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+---------+-------------+-----------+-----------+--------------+------------+------------+-----------+----------+-----------+
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| 46713:1 | 46713 | X | TABLE | `SYS_TABLES` | NULL | NULL | NULL | NULL | NULL | |
| 46712:1 | 46712 | X | TABLE | `SYS_TABLES` | NULL | NULL | NULL | NULL | NULL | |
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SELECT
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-> trx_id,
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-> trx_state,
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-> trx_started,
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-> trx_requested_lock_id,
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-> trx_wait_started,
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-> trx_mysql_thread_id,
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-> trx_query
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-> FROM information_schema.innodb_trx
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-> ORDER BY trx_started;
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| trx_id | trx_state | trx_started | trx_requested_lock_id | trx_wait_started | trx_mysql_thread_id | trx_query |
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| 46712 | RUNNING | 2025-10-17 11:47:33 | NULL | NULL | 30057 | CREATE TABLE test123455 ( |
id BIGINT PRIMARY KEY,
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dane VARCHAR(255) NOT NULL |
) |
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| 46713 | LOCK WAIT | 2025-10-17 11:49:53 | 46713:1 | 2025-10-17 11:49:53 | 30165 | CREATE TABLE IF NOT EXISTS test_users ( |
id INT AUTO_INCREMENT PRIMARY KEY,
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username VARCHAR(50) NOT NULL, |
email VARCHAR(100) NOT NULL, |
first_name VARCHAR(50), |
last_name VARCHAR(50), |
age INT,
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salary DECIMAL(10,2), |
department VARCHAR(50), |
hire_date DATE,
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is_active BOOLEAN DEFAULT TRUE,
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created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
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INDEX idx_username (username),
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INDEX idx_email (email),
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INDEX idx_department (department),
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INDEX idx_hire_date (hire_date)
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) ENGINE=InnoDB |
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-----------------------------+
Attachments
Issue Links
- relates to
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- Open
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MDEV-29445 reorganise innodb buffer pool (and remove buffer pool chunks)
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- Closed
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- causes
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DEV-2452 Loading...