Queue
Push items into a queue and pull them out in order.
Do things in Queue
Add a Queue step and choose an Operation. Choose the row to see the fields of each.
Later steps read a step’s output by its name: see Use data from earlier steps.
Limits
- Queues are kept for the workspace, in the database. Test step uses its own copy, apart from published runs.
- One item holds at most 16 MB.
- One pull or peek takes at most 10,000 items.
Not in your list? See When an app isn’t here.
For developers
In the API, which calls apps pieces, Queue is pieceId: "queue" with actionId: "operate", set by operation. Get an app returns every field.
It can change something outside the run (writes_external). See How versions and side effects work.
Queue › Queue Operation
Push to, pull from, peek, measure, or clear a FIFO queue. The Test step uses its own copy of the queues, separate from published runs.
Push items
- Queue Name · Required
Name of the queue (its key).
- Items · Optional
Item to push. A JSON array pushes each element as a separate item; any other value pushes one item.
Pull items (removes) and Peek items (keeps)
- Queue Name · Required
Name of the queue (its key).
- Number of Items · Optional
How many items to pull/peek from the front of the queue. A pull whose items are more than one step may pass on (MAX_STEP_OUTPUT_BYTES, 16 MB by default) takes none and fails, so pull fewer at a time.
Default: 1.
Queue length and Clear queue
- Queue Name · Required
Name of the queue (its key).