> ## Documentation Index
> Fetch the complete documentation index at: https://docs.planasonix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Control flow

> Add conditional logic, error handling, and iteration to your pipelines.

**Control flow** nodes orchestrate *how* and *when* parts of the graph execute—branching on data, isolating failures, looping over sets, fanning out partitions, and kicking off other pipelines.

## Conditional

**Conditional** implements **if / else** branching based on expressions or parameter values.

**Configuration:**

* **Predicate**: Boolean expression or rule set evaluated at the decision point.
* **True / false paths**: Distinct downstream subgraphs wired from each branch output.

**Typical use:** When `load_type = 'full_refresh'`, run a truncate-and-load subgraph; otherwise run incremental merge logic.

<Info>
  Clearly label branch outputs in large graphs so reviewers know which path corresponds to which business case.
</Info>

## Error Handler

**Error Handler** wraps a **try / catch** region around a subgraph.

**Configuration:**

* **Protected region**: Nodes whose failures should not abort the entire run (when configured).
* **Catch path**: Steps for logging, notifications, dead-letter writes, or compensating actions.
* **Retry policy** (when available): Backoff and max attempts for transient failures.

**Typical use:** Isolate calls to flaky partner APIs—on failure, write the payload to a quarantine table and alert on-call.

## ForEach

**ForEach** iterates over **records** or a list parameter, executing a child graph per item.

**Configuration:**

* **Iterator source**: Query, parameter list, or column collection.
* **Loop body**: Downstream nodes referencing the current item via variables.
* **Parallelism**: Limit concurrent iterations to protect shared systems.

**Typical use:** Process ten regional exports with the same logic—parameterize bucket names per row instead of cloning pipelines.

## Split

**Split** **partitions** a dataset into multiple outputs by predicate, hash, or key ranges—useful for parallel writes or A/B processing paths.

**Configuration:**

* **Rules per output**: Mutually exclusive filters or modulo buckets.
* **Default branch**: Catch-all for unexpected values.

**Typical use:** Send `country = 'US'` rows to one warehouse share and `EU` rows to another while keeping one authoring graph.

## Trigger Pipeline

**Trigger Pipeline** starts another Planasonix pipeline by reference.

**Configuration:**

* **Target pipeline** and **version** or label (per product).
* **Parameters / variables** passed into the child run.
* **Wait behavior**: Fire-and-forget vs wait for completion for chaining SLAs.

**Typical use:** A lightweight orchestrator graph that sequences domain-specific jobs after a shared staging refresh completes.

## Trigger Reverse ETL

**Trigger Reverse ETL** kicks off a **reverse ETL sync** or related outbound job defined in your workspace.

**Configuration:**

* **Sync identifier**: Which reverse ETL configuration to run.
* **Rowset or keys** (when supported): Limit the sync to a cohort produced upstream.

**Typical use:** After curated metrics land in the warehouse, push refreshed segments to Salesforce or an ads platform on demand.

<Warning>
  Chained triggers can amplify load. Rate-limit downstream SaaS APIs and respect partner daily quotas.
</Warning>

## Modeling patterns

<AccordionGroup>
  <Accordion title="Prefer small orchestrator graphs">
    Keep “traffic cop” pipelines thin—Trigger Pipeline nodes and parameters—while heavy transforms live in dedicated graphs you can test independently.
  </Accordion>

  <Accordion title="Combine with notifications">
    Pair **Error Handler** catch paths with [Notification](/nodes/data-quality) nodes so failures become tickets, not silent skips.
  </Accordion>
</AccordionGroup>

## Related reading

<CardGroup cols={2}>
  <Card title="Orchestration" icon="clock" href="/orchestration/overview">
    Schedules, triggers, and platform-level execution.
  </Card>

  <Card title="Pipeline canvas" icon="diagram-project" href="/pipelines/canvas">
    Wire control-flow outputs like any other node.
  </Card>
</CardGroup>