EachParallel
type: "io.kestra.core.tasks.flows.EachParallel"
For each value in the list, execute one or more tasks in parallel.
The list of tasks
will be executed for each item in parallel. The value must be a valid JSON string representing an array, e.g. a list of strings ["value1", "value2"]
or a list of dictionaries [{"key": "value1"}, {"key": "value2"}]
.
You can access the current iteration value using the variable null
.
The task list will be executed in parallel for each item. For example, if you have a list with 3 elements and 2 tasks defined in the list of tasks
, all 6 tasks will be computed in parallel without any order guarantee.
If you want to execute a group of sequential tasks for each value in parallel, you can wrap the list of tasks
with the Sequential task.
If your list of values is large, you can limit the number of concurrent tasks using the concurrent
property.
We highly recommend triggering a subflow for each value instead of specifying many tasks wrapped in a Sequential
task. This allows much better scalability and modularity. Check the flow best practices documentation and the following Blueprint for more details.
Examples
id: "each_parallel"
type: "io.kestra.core.tasks.flows.EachParallel"
value: '["value 1", "value 2", "value 3"]'
tasks:
- id: each-value
type: io.kestra.core.tasks.debugs.Return
format: "{{ task.id }} with current value '{{ taskrun.value }}'"
id: "each_parallel"
type: "io.kestra.core.tasks.flows.EachParallel"
value:
- value 1
- value 2
- value 3
tasks:
- id: each-value
type: io.kestra.core.tasks.debugs.Return
format: "{{ task.id }} with current value '{{ taskrun.value }}'"
Handling each value in parallel but only 1 child task for each value at the same time.
id: "each_parallel"
type: "io.kestra.core.tasks.flows.EachParallel"
value: '["value 1", "value 2", "value 3"]'
tasks:
- id: seq
type: io.kestra.core.tasks.flows.Sequential
tasks:
- id: t1
type: io.kestra.plugin.scripts.shell.Commands
commands:
- 'echo "{{task.id}} > {{ parents[0].taskrun.value }}
- 'sleep 1'
- id: t2
type: io.kestra.plugin.scripts.shell.Commands
commands:
- 'echo "{{task.id}} > {{ parents[0].taskrun.value }}
- 'sleep 1'
Properties
concurrent
- Type: integer
- Dynamic: ❌
- Required: ✔️
- Default:
0
Number of concurrent parallel tasks
If the value is 0
, no limit exist and all the tasks will start at the same time
tasks
- Type: array
- SubType: Task
- Dynamic: ❌
- Required: ✔️
- Min items:
1
value
- Type:stringarray
- Dynamic: ✔️
- Required: ✔️
The list of values for this task
The value car be passed as a String, a list of String, or a list of objects
errors
- Type: array
- SubType: Task
- Dynamic: ❌
- Required: ❌
List of tasks to run if any tasks failed on this FlowableTask