Enforce SLAs and Alert When Workflows Miss Performance Targets
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SLAs define time or assertion-based checks on flow executions and trigger corrective actions when those checks fail.

Use the sla property at the root of a flow to declare one or more SLA checks. Each SLA specifies a type, the condition to check, and a behavior to trigger when the condition is violated.

SLA types

Kestra supports two SLA types:

  1. MAX_DURATION — the maximum allowed execution duration before the SLA is breached
  2. EXECUTION_ASSERTION — a Pebble expression that must evaluate to true during execution. If it evaluates to false, the SLA is breached.

MAX_DURATION

The following SLA cancels an execution if it runs for more than 8 hours:

id: sla_example
namespace: company.team


sla:
  - id: maxDuration
    type: MAX_DURATION
    duration: PT8H
    behavior: CANCEL
    labels:
      sla: miss
      reason: durationExceeded


tasks:
  - id: punctual
    type: io.kestra.plugin.core.log.Log
    message: Workflow started, monitoring SLA compliance


  - id: sleepyhead
    type: io.kestra.plugin.core.flow.Sleep
    duration: PT9H


  - id: never_executed_task
    type: io.kestra.plugin.core.log.Log
    message: This task will never start because the SLA was breached

EXECUTION_ASSERTION

EXECUTION_ASSERTION evaluates a Pebble expression against the execution at runtime. The following SLA fails the execution if mytask does not return expected output:

id: sla_demo
namespace: company.team


sla:
  - id: assert_output
    type: EXECUTION_ASSERTION
    assert: "{{ outputs.mytask.value == 'expected output' }}"
    behavior: FAIL
    labels:
      sla: miss
      reason: outputMismatch


tasks:
  - id: mytask
    type: io.kestra.plugin.core.debug.Return
    format: expected output

SLA behavior

The behavior property controls what happens when the SLA is breached:

  1. CANCEL — cancels the execution
  2. FAIL — fails the execution
  3. NONE — logs a message without stopping the execution

Each SLA can also set labels on the breached execution, making it easy to filter affected executions or trigger follow-up actions.

Alerts on SLA breaches

Use a Flow trigger on the sla: miss label to send an alert whenever an SLA is breached:

id: sla_miss_alert
namespace: system


tasks:
  - id: send_alert
    type: io.kestra.plugin.slack.notifications.SlackIncomingWebhook
    url: "{{ secret('SLACK_WEBHOOK') }}"
    messageText: "SLA breached for flow `{{ trigger.namespace }}.{{ trigger.flowId }}` with ID `{{ trigger.executionId }}`"


triggers:
  - id: alert_on_failure
    type: io.kestra.plugin.core.trigger.Flow
    dependsOn:
      - labels:
          sla: miss
        states: [FAILED, WARNING, CANCELLED]

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