Querying the Top I/O Threads

Function

This API is used to query top I/O statistics of instance database processes and return the results associated with session information. Before calling this API:

Learn how to authenticate this API.
Obtain the required region and endpoint.

Constraints

The resource types and operating systems of instances must support the pidstat command.

URI

GET https://{Endpoint}/v3/{project_id}/instances/{instance_id}/top-io-traffics?node_id={node_id}&component_id={component_id}&top_io_num={top_io_num}&sort_condition={sort_condition}

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
project_id	Yes	String	Explanation: Project ID of a tenant in a region. For details about how to obtain the project ID, see Obtaining a Project ID. Restrictions: None Value range: The value can contain 32 characters. Only letters and digits are allowed. Default value: None
instance_id	Yes	String	Instance ID.
node_id	Yes	String	Node ID. It must be a DN node of a non-log role or a CN node, and the node status must be normal. To obtain the value, see Querying the Components of a DB Instance.
component_id	Yes	String	Component ID. It must be a CN or a DN component of a non-log role. To obtain the value, see Querying the Components of a DB Instance. Data node (DN): stores and queries table data. Coordinator node (CN): stores database metadata, distributes and executes query tasks, and then returns the query results from DNs to applications.
top_io_num	No	Integer	Number of top I/O threads to be queried in the database process. The default value is 20. The returned result includes information about the top I/O threads with associated session information. The number of records returned in the result cannot exceed the value of this parameter.
sort_condition	No	String	Top I/O sorting condition. Value: read write

Request Parameters

None

Response Parameters

**Table 2** Parameter description
Parameter	Type	Description
top_io_infos	Array of objects	I/O information. Each element in the list indicates an I/O record. For details, see Table 3.

**Table 3** top_io_infos field data structure description
Parameter	Type	Description
thread_id	String	Thread ID.
thread_type	String	Thread type. The value can be worker or background. To use this parameter, set enable_thread_pool to on. Value: worker background
disk_read_rate	Integer	Rate of reading data from disks, in KB/s.
disk_write_rate	Integer	Rate of writing data to the disk, in KB/s.
session_id	String	Session ID.
unique_sql_id	String	SQL ID.
database_name	String	Database.
client_ip	String	IP address of the client.
user_name	String	Username.
state	String	Status.
sql_start	Integer	Start time of the statement.

Example Request

Top I/Os queried.

GET https://gaussdb-opengauss.ap-southeast-1.myhuaweicloud.com/v3/0483b6b16e954cb88930a360d2c4e663/instances/{instance_id}/top-io-traffics?node_id=42cbf784585e419d9eb33c005f4ced94no14&component_id=dn_6001&top_io_num=20&sort_condition=write

Example Response

{ 
  "top_io_infos" : [ { 
    "thread_id" : "55067", 
    "thread_type" : "worker", 
    "disk_read_rate" : 0, 
    "disk_write_rate" : 1.43, 
    "session_id" : "725", 
    "unique_sql_id" : "3545025713", 
    "database_name" : "postgres", 
    "client_ip" : "23.100.74.131", 
    "user_name" : "root", 
    "state" : "active", 
    "sql_start" : 1690448618689 
  } ] 
}