SUBMIT TASK
Description
Submits an ETL statement as an asynchronous task. This feature has been supported since StarRocks v2.5.
Currently, StarRocks supports submitting asynchronous tasks for CREATE TABLE AS SELECT and INSERT.
You can drop an asynchronous task using DROP TASK.
Syntax
SUBMIT TASK [task_name] AS <etl_statement>
Parameters
| Parameter | Description |
|---|---|
| task_name | The task name. |
| etl_statement | The ETL statement that you want to submit as an asynchronous task. StarRocks currently supports submitting asynchronous tasks for CREATE TABLE AS SELECT and INSERT. |
Usage notes
This statement creates a Task, which is a template for storing a task that executes the ETL statement. You can check the information of the Task by querying the metadata table tasks in Information Schema.
SELECT * FROM INFORMATION_SCHEMA.tasks;
SELECT * FROM information_schema.tasks WHERE task_name = '<task_name>';
After you run the Task, a TaskRun is generated accordingly. A TaskRun indicates a task that executes the ETL statement. A TaskRun has the following states:
PENDING: The task waits to be run.RUNNING: The task is running.FAILED: The task failed.SUCCESS: The task runs successfully.
You can check the state of a TaskRun by querying the metadata table task_runs in Information Schema.
SELECT * FROM INFORMATION_SCHEMA.task_runs;
SELECT * FROM information_schema.task_runs WHERE task_name = '<task_name>';
Configure via FE configuration items
You can configure asynchronous ETL tasks using the following FE configuration items:
| Parameter | Default value | Description |
|---|---|---|
| task_ttl_second | 86400 | The period during which a Task is valid. Unit: seconds. Tasks that exceed the validity period are deleted. Here, a Task indicates a non-periodic task that is performed only once. |
| task_check_interval_second | 3600 | The time interval to delete invalid Tasks. Unit: seconds. |
| task_runs_ttl_second | 86400 | The period during which a TaskRun is valid. Unit: seconds. TaskRuns that exceed the validity period are deleted automatically. Additionally, TaskRuns in the FAILED and SUCCESS states are also deleted automatically. A TaskRun is an individual run of a periodic task. |
| task_runs_concurrency | 4 | The maximum number of TaskRuns that can be run in parallel. |
| task_runs_queue_length | 500 | The maximum number of TaskRuns that are pending for running. If the number exceeds the default value, the incoming tasks will be suspended. |
| task_runs_max_history_number | 10000 | The maximum number of TaskRun records to retain. |
Examples
Example 1: Submit an asynchronous task for CREATE TABLE tbl1 AS SELECT * FROM src_tbl, and specify the task name as etl0:
SUBMIT TASK etl0 AS CREATE TABLE tbl1 AS SELECT * FROM src_tbl;
Example 2: Submit an asynchronous task for INSERT INTO tbl2 SELECT * FROM src_tbl, and specify the task name as etl1:
SUBMIT TASK etl1 AS INSERT INTO tbl2 SELECT * FROM src_tbl;
Example 3: Submit an asynchronous task for INSERT OVERWRITE tbl3 SELECT * FROM src_tbl:
SUBMIT TASK AS INSERT OVERWRITE tbl3 SELECT * FROM src_tbl;
Example 4: Submit an asynchronous task for INSERT OVERWRITE insert_wiki_edit SELECT * FROM source_wiki_edit without specifying the task name, and extend the query timeout to 100000 seconds using the hint:
SUBMIT /*+set_var(query_timeout=100000)*/ TASK AS
INSERT OVERWRITE insert_wiki_edit
SELECT * FROM source_wiki_edit;