Querying Wait Events

Function

This API is used to query wait events on a database instance node. Before calling this API:

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

Constraints

This API is only available for nodes with CNs or DNs (primary or standby DNs) deployed.

Debugging

You can debug this API in API Explorer.

URI

POST /v3/{project_id}/instances/{instance_id}/wait-event-list

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
project_id	Yes	String	Definition Project ID of a tenant in a region. To obtain the value, see Obtaining a Project ID. Constraints N/A Range The value can contain 32 characters. Only letters and digits are allowed. Default Value N/A
instance_id	Yes	String	Definition Instance ID, which uniquely identifies an instance. Constraints N/A Range The value can contain 36 characters. Only letters and digits are allowed. Default Value N/A

Request Parameters

**Table 2** Request header parameters
Parameter	Mandatory	Type	Description
X-Auth-Token	Yes	String	Definition User token. You can obtain the token by calling the IAM API used to obtain a user token. After the request is processed, the value of X-Subject-Token in the message header is the token value. Constraints N/A Range N/A Default Value N/A
X-Language	No	String	Definition Language. Constraints N/A Range zh-cn en-us Default Value en-us

**Table 3** Request body parameters
Parameter	Mandatory	Type	Description
node_id	Yes	String	Definition Node ID. This parameter is available only for nodes with CNs or DNs (primary or standby DNs) deployed. Constraints N/A Range N/A Default Value N/A
system	No	Boolean	Definition Whether to query data of system users. Constraints N/A Range N/A Default Value false
offset	No	Integer	Definition Index offset. The query starts from the next piece of data indexed by this parameter. Constraints The value must be a non-negative integer. Range N/A Default Value 0: The query starts from the first data record.
limit	No	Integer	Definition Number of records returned by a query. Constraints The value cannot be negative. Range [1,100] Default Value 10
order_fields	No	List<List<String>>	Definition Sorting fields. Internally represented as List<String>, where the first element specifies the field to sort by, and the second element indicates the sort order. Constraints N/A
wait_event_query_info	No	Object	Definition Filtering conditions for obtaining wait events. For details, see Table 4. Constraints N/A

**Table 4** Parameter description of the **WaitEventQueryInfo** field
Parameter	Mandatory	Type	Description
database_name	No	String	Definition Database name. Constraints N/A Range N/A Default Value N/A
user_name	No	String	Definition Username. Constraints N/A Range N/A Default Value N/A
waiting	No	String	Definition Whether it is in the waiting state. Constraints N/A Range t: yes f: no Default Value N/A
session_id	No	String	Definition Session ID. Constraints N/A Range N/A Default Value N/A

Response Parameters

**Table 5** Response body parameters
Parameter	Type	Description
total	Integer	Definition Total number of wait events. Range N/A
rows	Array of objects	Definition Wait events of the database instance. For details, see Table 6.

**Table 6** Parameter description of the **WaitEvent** field
Parameter	Type	Description
session_id	String	Definition Session ID. Range N/A
pid	String	Definition Thread ID. Range N/A
wait_event	String	Definition Wait event. For details, see the wait_event field in "Developer Guide" > "System Catalogs and System Views" > "System Views" > "Other System Views" > "PG_THREAD_WAIT_STATUS". Range N/A
wait_status	String	Definition Wait status. For details, see the wait_status field in "Developer Guide" > "System Catalogs and System Views" > "System Views" > "Other System Views" > "PG_THREAD_WAIT_STATUS". Range N/A
database_name	String	Definition Database. Range N/A
user_name	String	Definition Username. Range N/A
client_addr	String	Definition Client address. Range N/A
client_port	String	Definition TCP port number used by a client to communicate with the backend. Range N/A
session_time	String	Definition Session duration, in seconds. Range N/A
xact_start	String	Definition Session start time. Range N/A
transaction_time	String	Definition Transaction duration, in seconds. Range N/A
query_start	String	Definition Query start time. Range N/A
state_change	String	Definition Time when state was last changed. Range N/A
query_time	String	Definition Query duration, in seconds. Range N/A
backend_start	String	Definition Session start time. Range N/A
waiting	String	Definition Whether to wait for a lock. Range t: yes f: no
lockmode	String	Definition Lock mode (awaiting acquisition). Range N/A
block_sessionid	String	Definition ID of a blocked session. Range N/A
block_count	String	Definition Number of blocked sessions. Range N/A
unique_sql_id	String	Definition Normalized SQL ID. Range N/A
query_id	String	Definition Query ID. Range N/A
query	String	Definition SQL text. Range N/A
current_xid	String	Definition Current transaction ID. Range N/A
top_xid	String	Definition Top-level transaction ID. Range N/A
xlog_quantity	String	Definition Amount of Xlogs currently used by a transaction, in bytes. Range N/A
state	String	Definition Overall state of the session. Range active: The backend is executing a query. idle: The backend is waiting for a new client command. idle in transaction: The backend is in a transaction, but there is no statement being executed in the transaction. fastpath function call: The backend is executing a fast-path function. disabled: This state is displayed if track_activities is disabled in the backend.
application_name	String	Definition Application name. Range N/A
connection_info	String	Definition Connection information. Range N/A

Example Request

POST https://gaussdb-opengauss.ap-southeast-1.myhuaweicloud.com/v3/0483b6b16e954cb88930a360d2c4e663/instances/cc6fd964d93f4003851dfc29d57d30a5in14/wait-event-list
{
    "node_id": "1fafb3b79c4b41cdb2f8ecd90a80ba5eno14",
    "limit": 1,
    "offset": 10,
    "order_fields": [["query_start", "ASC"]],
    "wait_event_query_info": {
        "database_name": "postgres"
    }
}

Example Response

{
    "total": 1,
    "rows": [
        {
            "session_id": "3377",
            "database_name": "postgres",
            "user_name": "root",
            "unique_sql_id": "3545025713",
            "query_id": "1949495688698202784",
            "pid": "139646718113344",
            "client_addr": "127.0.0.1",
            "client_port": "50856",
            "state": "active",
            "query": "select pg_sleep(300);",
            "application_name": "gsql",
            "wait_event": "wait gs_sleep",
            "wait_status": "wait gs_sleep",
            "session_time": "76",
            "xact_start": "2024-12-21 14:29:38.360946+08",
            "transaction_time": "73",
            "query_start": "2024-12-21 14:29:38.360946+08",
            "state_change": "2024-12-21 14:29:38.360956+08",
            "query_time": "73934470",
            "backend_start": "2024-12-21 14:29:35.728347+08",
            "waiting": "f",
            "lockmode": "",
            "block_sessionid": "",
            "block_count": "",
            "current_xid": "0",
            "top_xid": "0",
            "xlog_quantity": "0",
            "connection_info": "{\"driver_name\":\"libpq\",\"driver_version\":\"(GaussDB Kernel 505.2.1 build 22cc96d0) compiled at 2024-11-27 02:07:13 commit 10063 last mr 20829 release\"}"
        }
    ]
}