Task Lifecycle

Applies to both editions

This page describes the Conductor engine that powers both open-source Conductor and Orkes Conductor. Operational defaults mentioned here, such as Redis or Elasticsearch, are specifics of the open-source distribution; Orkes Conductor deployments run the Orkes platform stack.

State diagram

Every task starts in SCHEDULED when it enters its queue. A worker poll moves it to IN_PROGRESS, and a successful result moves it to COMPLETED. The other transitions cover failure: FAILED and TIMED_OUT tasks return to SCHEDULED for retry until their retries are exhausted, and every other state is terminal.

%%{init: {'look': 'handDrawn', 'theme': 'base', 'themeVariables': {'primaryColor': '#eef2ff', 'primaryBorderColor': '#1e40af', 'primaryTextColor': '#1e293b', 'lineColor': '#1e3a8a', 'edgeLabelBackground': '#ffffff', 'clusterBkg': '#fbfcff', 'clusterBorder': '#2563eb', 'fontFamily': '-apple-system, system-ui, Segoe UI, Roboto, Helvetica, Arial, sans-serif', 'fontSize': '15px'}, 'flowchart': {'nodeSpacing': 50, 'rankSpacing': 58, 'padding': 14, 'htmlLabels': true, 'curve': 'basis'}}}%%
stateDiagram-v2
    [*] --> SCHEDULED
    SCHEDULED --> IN_PROGRESS : Worker polls task
    SCHEDULED --> TIMED_OUT : Poll timeout exceeded
    SCHEDULED --> CANCELED : Workflow terminated
    IN_PROGRESS --> COMPLETED : Worker reports success
    IN_PROGRESS --> FAILED : Worker reports failure
    IN_PROGRESS --> FAILED_WITH_TERMINAL_ERROR : Non-retryable failure
    IN_PROGRESS --> TIMED_OUT : Response/task timeout exceeded
    IN_PROGRESS --> COMPLETED_WITH_ERRORS : Optional task fails
    SCHEDULED --> SKIPPED : Skip Task API called
    FAILED --> SCHEDULED : Retry (after delay)
    TIMED_OUT --> SCHEDULED : Retry (after delay)
    COMPLETED --> [*]
    FAILED --> [*] : Retries exhausted or totalTimeoutSeconds exceeded
    FAILED_WITH_TERMINAL_ERROR --> [*]
    TIMED_OUT --> [*] : Retries exhausted or totalTimeoutSeconds exceeded
    CANCELED --> [*]
    SKIPPED --> [*]
    COMPLETED_WITH_ERRORS --> [*]

Task statuses

Status	Description
SCHEDULED	Task is queued and waiting for a worker to poll it.
IN_PROGRESS	A worker has picked up the task and is executing it.
COMPLETED	Task completed successfully.
FAILED	Task failed due to an error. Conductor will retry based on the task definition's retry configuration.
FAILED_WITH_TERMINAL_ERROR	Task failed with a non-retryable error. No retries will be attempted.
TIMED_OUT	Task exceeded its configured timeout. Conductor will retry based on the retry configuration.
CANCELED	Task was canceled because the workflow was terminated.
SKIPPED	Task was skipped via the Skip Task API. The workflow continues to the next task.
COMPLETED_WITH_ERRORS	Task failed but is marked as optional in the workflow definition. The workflow continues.

Retry behavior

When a task fails with a retryable error, Conductor automatically reschedules it after the configured delay.

%%{init: {'look': 'handDrawn', 'theme': 'base', 'themeVariables': {'primaryColor': '#eef2ff', 'primaryBorderColor': '#1e40af', 'primaryTextColor': '#1e293b', 'lineColor': '#1e3a8a', 'edgeLabelBackground': '#ffffff', 'clusterBkg': '#fbfcff', 'clusterBorder': '#2563eb', 'fontFamily': '-apple-system, system-ui, Segoe UI, Roboto, Helvetica, Arial, sans-serif', 'fontSize': '15px'}, 'flowchart': {'nodeSpacing': 50, 'rankSpacing': 58, 'padding': 14, 'htmlLabels': true, 'curve': 'basis'}}}%%
sequenceDiagram
    participant W as Worker
    participant C as Conductor Server

    C->>W: Task T1 available for polling
    W->>C: Poll task T1
    C-->>W: Return T1 (IN_PROGRESS)
    W->>W: Process task...
    W->>C: Report FAILED (after 10s)
    C->>C: Persist failed execution
    Note over C: Wait retryDelaySeconds (5s)
    C->>C: Schedule new T1 execution
    C->>W: T1 available for polling again
    W->>C: Poll task T1
    C-->>W: Return T1 (IN_PROGRESS)
    W->>W: Process task...
    W->>C: Report COMPLETED

Retry behavior is controlled by the task definition:

Parameter	Description
retryCount	Maximum number of retry attempts.
retryLogic	FIXED, EXPONENTIAL_BACKOFF, or LINEAR_BACKOFF. See Retry Logic.
retryDelaySeconds	Base delay between retries.
maxRetryDelaySeconds	Caps the computed delay. Prevents exponential growth from becoming arbitrarily large.
backoffJitterMs	Adds random milliseconds to each delay to spread concurrent retries over time.
totalTimeoutSeconds	Hard wall-clock budget across all attempts. See Total timeout.

Timeout scenarios

Poll timeout

If no worker polls the task within pollTimeoutSeconds, it is marked as TIMED_OUT.

%%{init: {'look': 'handDrawn', 'theme': 'base', 'themeVariables': {'primaryColor': '#eef2ff', 'primaryBorderColor': '#1e40af', 'primaryTextColor': '#1e293b', 'lineColor': '#1e3a8a', 'edgeLabelBackground': '#ffffff', 'clusterBkg': '#fbfcff', 'clusterBorder': '#2563eb', 'fontFamily': '-apple-system, system-ui, Segoe UI, Roboto, Helvetica, Arial, sans-serif', 'fontSize': '15px'}, 'flowchart': {'nodeSpacing': 50, 'rankSpacing': 58, 'padding': 14, 'htmlLabels': true, 'curve': 'basis'}}}%%
sequenceDiagram
    participant W as Worker
    participant C as Conductor Server

    C->>C: Schedule task T1
    Note over C,W: No worker polls within 60s
    C->>C: Mark T1 as TIMED_OUT
    C->>C: Schedule retry (if retries remain)

This typically indicates a backlogged task queue or insufficient workers.

Response timeout

If a worker polls a task but doesn't report back within responseTimeoutSeconds, the task is marked as TIMED_OUT. This handles cases where a worker crashes mid-execution.

%%{init: {'look': 'handDrawn', 'theme': 'base', 'themeVariables': {'primaryColor': '#eef2ff', 'primaryBorderColor': '#1e40af', 'primaryTextColor': '#1e293b', 'lineColor': '#1e3a8a', 'edgeLabelBackground': '#ffffff', 'clusterBkg': '#fbfcff', 'clusterBorder': '#2563eb', 'fontFamily': '-apple-system, system-ui, Segoe UI, Roboto, Helvetica, Arial, sans-serif', 'fontSize': '15px'}, 'flowchart': {'nodeSpacing': 50, 'rankSpacing': 58, 'padding': 14, 'htmlLabels': true, 'curve': 'basis'}}}%%
sequenceDiagram
    participant W as Worker
    participant C as Conductor Server

    C->>W: Task T1 available
    W->>C: Poll T1
    C-->>W: Return T1 (IN_PROGRESS)
    W->>W: Processing...
    Note over W: Worker crashes
    Note over C: responseTimeoutSeconds (20s) elapsed
    C->>C: Mark T1 as TIMED_OUT
    Note over C: Wait retryDelaySeconds (5s)
    C->>C: Schedule new T1 execution

Workers can extend the response timeout by sending IN_PROGRESS status updates with a callbackAfterSeconds value.

Task timeout

timeoutSeconds is the overall SLA for task completion. Even if a worker keeps sending IN_PROGRESS updates, the task is marked as TIMED_OUT once this duration is exceeded.

%%{init: {'look': 'handDrawn', 'theme': 'base', 'themeVariables': {'primaryColor': '#eef2ff', 'primaryBorderColor': '#1e40af', 'primaryTextColor': '#1e293b', 'lineColor': '#1e3a8a', 'edgeLabelBackground': '#ffffff', 'clusterBkg': '#fbfcff', 'clusterBorder': '#2563eb', 'fontFamily': '-apple-system, system-ui, Segoe UI, Roboto, Helvetica, Arial, sans-serif', 'fontSize': '15px'}, 'flowchart': {'nodeSpacing': 50, 'rankSpacing': 58, 'padding': 14, 'htmlLabels': true, 'curve': 'basis'}}}%%
sequenceDiagram
    participant W as Worker
    participant C as Conductor Server

    C->>W: Task T1 available
    W->>C: Poll T1
    C-->>W: Return T1 (IN_PROGRESS)
    W->>W: Processing...
    W->>C: IN_PROGRESS (callback: 9s)
    Note over C: Task back in queue, invisible 9s
    W->>C: Poll T1 again
    W->>C: IN_PROGRESS (callback: 9s)
    Note over C: Cycle repeats...
    Note over C: timeoutSeconds (30s) elapsed
    C->>C: Mark T1 as TIMED_OUT
    C->>C: Schedule retry (if retries remain)
    W->>C: Report COMPLETED (at 32s)
    Note over C: Ignored — T1 already terminal

Total timeout

totalTimeoutSeconds limits the total wall-clock time across all retry attempts. Once this budget is consumed, no further retries are scheduled regardless of how many remain in retryCount.

%%{init: {'look': 'handDrawn', 'theme': 'base', 'themeVariables': {'primaryColor': '#eef2ff', 'primaryBorderColor': '#1e40af', 'primaryTextColor': '#1e293b', 'lineColor': '#1e3a8a', 'edgeLabelBackground': '#ffffff', 'clusterBkg': '#fbfcff', 'clusterBorder': '#2563eb', 'fontFamily': '-apple-system, system-ui, Segoe UI, Roboto, Helvetica, Arial, sans-serif', 'fontSize': '15px'}, 'flowchart': {'nodeSpacing': 50, 'rankSpacing': 58, 'padding': 14, 'htmlLabels': true, 'curve': 'basis'}}}%%
sequenceDiagram
    participant W as Worker
    participant C as Conductor Server

    Note over C: totalTimeoutSeconds = 30s
    C->>W: Task T1 (attempt 1)
    W->>C: FAILED (at t=5s)
    Note over C: Retry delay 5s
    C->>W: Task T1 (attempt 2, at t=10s)
    W->>C: FAILED (at t=20s)
    Note over C: Retry delay 5s
    C->>W: Task T1 (attempt 3, at t=25s)
    W->>C: FAILED (at t=28s)
    Note over C: t=28s ≥ 30s → total budget exhausted
    C->>C: Mark workflow FAILED — no more retries

This is useful when you need a hard SLA on how long a task can run across all its attempts, independent of how many retries are configured.

Timeout configuration summary

Parameter	Description	Default
pollTimeoutSeconds	Max time for a worker to poll the task.	No timeout
responseTimeoutSeconds	Max time for a worker to respond after polling.	600s
timeoutSeconds	SLA per individual attempt (from first IN_PROGRESS to terminal).	No timeout
totalTimeoutSeconds	Hard budget across all attempts combined. Overrides retryCount.	No timeout
timeoutPolicy	Action on timeout: RETRY, TIME_OUT_WF (fail workflow), or ALERT_ONLY.	TIME_OUT_WF

Related pages

• Core Concepts
• Why Conductor
• Architecture Overview
• Durable Execution Semantics
• JSON + Code Native Workflow Orchestration