SHOW PROCESSLIST

Grammar Description

SHOW PROCESSLIST is used to view the currently executing list of threads (also known as process lists) and provides information about all active connections and queries in execution on the MatrixOne Intelligence server.

SHOW PROCESSLIST is used to monitor and manage activities in databases, identify potential problems, help query performance problems, and help decision-making to optimize the database’s operation:

• Monitor database activity: By executing SHOW PROCESSLIST, you can view the currently running queries and operations in the database in real time. This is useful for monitoring database activity and promptly detecting possible performance issues. You can learn which queries are running, how they are in status, and whether there are long-running or blocking queries, or locking, deadlocking, or resource contention, etc.

• Terminate query: By viewing the process list, you can determine the query ID to be terminated and use the KILL command to terminate the specific query. This is very useful for stopping long-running queries or solving deadlock problems.

Grammar Structure

> SHOW PROCESSLIST;

The query table structure fields are explained as follows:

Column Name	Type	Constraints	Notes
node_id	varchar	not null	Node ID, used to uniquely identify different nodes in the database cluster. In MatrixOne Intelligence, a node is a CN (Compute Node). Note: - In MatrixOne Intelligence, each node has a unique node_id. System tenants can view the node_id corresponding to the node where all executing threads are located, while system tenants can only see the node_id corresponding to the node that belongs to the threads that are executing under their tenants.
conn_id	uint32	not null	Connection ID, used to identify different database connections. If you need to terminate a database connection, you can use the KILL CONNECTION conn_id; command to terminate the connection. In the database, each connection is assigned a unique conn_id to identify the connection. Note: System tenants can view all conn_ids, while non-system tenants can only see conn_ids under the tenant. ID
session_id	varchar	not null	session ID
account	varchar	not null	Tenant Note: The sessions and tenant names of all tenants can be seen under the system tenant, while non-system tenants can only see the sessions and tenant names of their own tenants.
user	varchar	not null	user
host	varchar	not null	client side host name
db	varchar		Database Name
session_start	varchar		session start time
command	varchar	not null	Command type, such as COM_QUERY
info	varchar		Current or previous SQL statement
txn_id	varchar	not null	Current or previous transaction ID
statement_id	varchar		Current or previous statement ID
statement_type	varchar		Current or previous statement type
query_type	varchar		query types, such as DDL, DML, etc
sql_source_type	varchar		SQL source types, such as external_sql, internal_sql, etc.
query_start	varchar		query start time

Example

mysql> SHOW PROCESSLIST;
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| node_id | conn_id | session_id | account | user | host | db | session_start | command | info | txn_id | statement_id | statement_type | query_type | sql_source_type | query_start |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| dd1dccb4-4d3c-41f8-b482-5251dc7a41bf |       1 | 97f85f80-2a5c-11ee-ae41-5ad2460dea4f | sys     | mo_logger                            | 127.0.0.1:6001 |         | 2023-07-24 19:59:27.005755 | COM_QUERY | COMMIT                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                  |                                      |                  |            | internal_sql    |                            |
| dd1dccb4-4d3c-41f8-b482-5251dc7a41bf |       8 | a056b7c6-2a5c-11ee-ae42-5ad2460dea4f | sys     | root                                 | 127.0.0.1:6001 | aab     | 2023-07-24 19:59:41.045851 | COM_QUERY | SHOW PROCESSLIST                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | c207acc30a19432f8d3cbac387c6e520 | 421aadaa-2a68-11ee-ae5b-5ad2460dea4f | Show Processlist | Other      | external_sql    | 2023-07-24 21:22:56.907266 |
| dd1dccb4-4d3c-41f8-b482-5251dc7a41bf |      24 | 0915f91a-2a63-11ee-ae4d-5ad2460dea4f | sys     | 3bf028e0-aa43-4917-b82f-ed533c0f401e | 127.0.0.1:6001 | mo_task | 2023-07-24 20:45:33.762679 | COM_QUERY | select
                                                task_id,
                                                        task_metadata_id,
                                                        task_metadata_executor,
                                                        task_metadata_context,
                                                        task_metadata_option,
                                                        task_parent_id,
                                                        task_status,
                                                        task_runner,
                                                        task_epoch,
                                                        last_heartbeat,
                                                        result_code,
                                                        error_msg,
                                                        create_at,
                                                        end_at
                                                from mo_task.sys_async_task where task_id>17 AND task_runner='dd1dccb4-4d3c-41f8-b482-5251dc7a41bf' AND task_status=1 order by task_id limit 3 |                                  |                                      |                  |            | internal_sql    |                            |
| dd1dccb4-4d3c-41f8-b482-5251dc7a41bf |      36 | d8aa4060-2a67-11ee-ae59-5ad2460dea4f | sys     | 3bf028e0-aa43-4917-b82f-ed533c0f401e | 127.0.0.1:6001 | mo_task | 2023-07-24 21:20:00.009746 | COM_QUERY | select
                                                cron_task_id,
                                                task_metadata_id,
                                                task_metadata_executor,
                                                task_metadata_context,
                                                task_metadata_option,
                                                cron_expr,
                                                next_time,
                                                trigger_times,
                                                create_at,
                                                update_at
                                                from mo_task.sys_cron_task                                                                                                                                                                        |                                  |                                      |                  |            | internal_sql    |                            |+--------------------------------------+---------+--------------------------------------+---------+--------------------------------------+----------------+---------+----------------------------+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+--------------------------------------+------------------+------------+-----------------+----------------------------+
4 rows in set (0.01 sec)