MEMORY_USAGE
The MEMORY_USAGE table describes the current memory usage of the current TiDB instance.
USE information_schema;
DESC memory_usage;
+--------------------+-------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------------+-------------+------+------+---------+-------+
| MEMORY_TOTAL | bigint(21) | NO | | NULL | |
| MEMORY_LIMIT | bigint(21) | NO | | NULL | |
| MEMORY_CURRENT | bigint(21) | NO | | NULL | |
| MEMORY_MAX_USED | bigint(21) | NO | | NULL | |
| CURRENT_OPS | varchar(50) | YES | | NULL | |
| SESSION_KILL_LAST | datetime | YES | | NULL | |
| SESSION_KILL_TOTAL | bigint(21) | NO | | NULL | |
| GC_LAST | datetime | YES | | NULL | |
| GC_TOTAL | bigint(21) | NO | | NULL | |
| DISK_USAGE | bigint(21) | NO | | NULL | |
| QUERY_FORCE_DISK | bigint(21) | NO | | NULL | |
+--------------------+-------------+------+------+---------+-------+
11 rows in set (0.000 sec)
SELECT * FROM information_schema.memory_usage;
+--------------+--------------+----------------+-----------------+-------------+---------------------+--------------------+---------------------+----------+------------+------------------+
| MEMORY_TOTAL | MEMORY_LIMIT | MEMORY_CURRENT | MEMORY_MAX_USED | CURRENT_OPS | SESSION_KILL_LAST | SESSION_KILL_TOTAL | GC_LAST | GC_TOTAL | DISK_USAGE | QUERY_FORCE_DISK |
+--------------+--------------+----------------+-----------------+-------------+---------------------+--------------------+---------------------+----------+------------+------------------+
| 33674170368 | 10737418240 | 5097644032 | 10826604544 | NULL | 2022-10-17 22:47:47 | 1 | 2022-10-17 22:47:47 | 20 | 0 | 0 |
+--------------+--------------+----------------+-----------------+-------------+---------------------+--------------------+---------------------+----------+------------+------------------+
2 rows in set (0.002 sec)
The columns in the MEMORY_USAGE table are described as follows:
- MEMORY_TOTAL: The total available memory of TiDB, in bytes.
- MEMORY_LIMIT: The memory usage limit of TiDB, in bytes. The value is the same as that of the system variable
tidb_server_memory_limit. - MEMORY_CURRENT: The current memory usage of TiDB, in bytes.
- MEMORY_MAX_USED: The maximum memory usage of TiDB from the time it is started to the current time, in bytes.
- CURRENT_OPS: "shrinking" | null. "shrinking" means that TiDB is performing operations that shrink memory usage.
- SESSION_KILL_LAST: The timestamp of the last time a session is terminated.
- SESSION_KILL_TOTAL: The number of times sessions are terminated, from the time TiDB is started to the current time.
- GC_LAST: The timestamp of the last time Golang GC is triggered by memory usage.
- GC_TOTAL: The number of times Golang GC is triggered by memory usage, from the time TiDB is started to the current time.
- DISK_USAGE: The disk usage for the current data spill operation, in bytes.
- QUERY_FORCE_DISK: The number of times data is spilled to disk, from the time TiDB is started to the current time.