​Task ​Runs

A Task Run is a single run of an individual task within an Execution, where an Execution is a single run of a flow. This means an Execution can have many Task Runs.

Each Task Run has associated data such as:

• Execution ID
• State
• Start Date
• End Date

Attempts

Each task run can have one or more attempts. Most task runs will have only one attempt, but you can configure retries for a task. If retries have been configured, a task failure will generate new attempts until the retry maxAttempt or maxDuration threshold is hit.

States

Similar to Executions, Task Runs cans be in a particular state.

Expression

You can access information about a taskrun using the {{ taskrun }} expression.

This example returns the information from {{ taskrun }}:

id: taskrun
namespace: company.team

tasks:
  - id: return
    type: io.kestra.plugin.core.debug.Return 
    format: "{{ taskrun }}"

The logs show the following:

{
    "id": "61TxwXQjkXfwTd4ANK6fhv",
    "startDate": "2024-11-13T14:38:38.355668Z",
    "attemptsCount": 0
}

Some Flowable Tasks, such as ForEach and ForEachItem, group tasks together. You can use the expression {{ taskrun.value }} to access the value for that task run.

In the example below, foreach will iterate twice over the values [1, 2]:

id: loop
namespace: company.team

tasks:
  - id: foreach
    type: io.kestra.plugin.core.flow.ForEach
    values: [1, 2]
    tasks:
      - id: log
        type: io.kestra.plugin.core.log.Log
        message: "{{ taskrun.value }}"

This outputs two separate log tasks, one with 1 and the other with 2.

You can also use the {{ parents }} expression to access a task run value from a parent task. Here's an example of it with ForEach:

id: loop
namespace: company.team

tasks:
  - id: foreach
    type: io.kestra.plugin.core.flow.ForEach
    values: [1, 2]
    tasks:
      - id: log
        type: io.kestra.plugin.core.log.Log
        message: "{{ taskrun.value }}"
      - id: if
        type: io.kestra.plugin.core.flow.If
        condition: "{{ true }}"
        then:
          - id: log_parent
            type: io.kestra.plugin.core.log.Log
            message: "{{ parents }}"

This will iterate through the log and if tasks twice as there are two items in values property.

The log_parent task outputs the task run value produced by foreach on the first iteration:

[
    {
        "taskrun": {
            "value": "1" 
        }
    }
]

Read more about it on the Expression Usage page.

Task Runs Page (EE)

If you have Kestra setup using the Kafka and Elasticsearch backend, you can view Task Runs in the UI.

It's similar to the Execution View but only shows Task Runs.