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While

The while step runs its nested steps repeatedly as long as a Kibana Query Language (KQL) condition evaluates to true. The condition is re-evaluated at the end of every iteration.

Use while for polling patterns: checking a status until it reaches ready, retrying an operation until it succeeds, or waiting for an external job to complete. For iterating over a known collection, use foreach instead.

Parameter Location Type Required Description
name top level string Yes Unique step identifier.
type top level string Yes Must be while.
condition top level string Yes KQL expression evaluated each iteration. The loop continues while it is true.
steps top level array Yes Loop body.
max-iterations top level number or object No Limit for number of iterations. Bare number is treated as { limit: N, on-limit: continue }. Use the object form to opt into on-limit: fail.
iteration-timeout top level duration No Per-iteration timeout.
iteration-on-failure top level object No Per-iteration error-handling policy. Same shape as on-failure.
Warning

while has no default max-iterations. Without an explicit cap, a while loop runs as long as its condition holds. Always set max-iterations on loops that depend on external state to avoid runaway executions.

# Bare number: default `on-limit` is `continue` (the step succeeds when the cap is hit)
max-iterations: 60

# Object form: opt into `on-limit: fail` to fail the workflow when the limit is reached
max-iterations:
  limit: 60
  on-limit: fail

Inside the steps block of a while, the following variables are available:

Variable Contains
while.iteration Zero-based iteration counter. 
- name: poll_job
  type: while
  condition: "steps.check.output.status : pending"
  max-iterations:
    limit: 60
    on-limit: fail
  steps:
    - name: check
      type: elasticsearch.search
      with:
        index: "jobs"
        query:
          term:
            id: "{{ inputs.job_id }}"
        size: 1

    - name: log_progress
      type: console
      with:
        message: "Attempt {{ while.iteration }}: status {{ steps.check.output.hits.hits[0]._source.status }}"

    - name: wait
      type: wait
      with:
        duration: "5s"

If the job hasn't left pending after 60 iterations (five minutes), the loop exits with failure.