Flow Logging

Overview

📘
Avilable starting from OpenLegacy Core version 5.1.0

Flow logging provides a comprehensive audit trail of metadata for every flow execution. It captures critical information such as the trigger source, execution path, step durations, and data payloads.

At the conclusion of each flow run, all metadata is emitted as a single structured JSON log entry via the logger io.openlegacy.flow.* at the INFO level.

Configuration

You can customize the depth of your logs using two independent dimensions. These can be defined in your application.yaml or via environment variables.

Logging Dimensions

Setting	Controls
`log-input-output`	Determines if the trigger payload and flow response body are included.
`step-level`	Determines the level of detail captured for each individual step.

Configuration Examples

YAML Setup

flow:
  logging:
    log-input-output: false   # Default
    step-level: none          # Options: none, basic, full

Environment Variables

OL_FLOW_LOGGING_LOG_INPUT_OUTPUT=true
OL_FLOW_LOGGING_STEP_LEVEL=full

Step-Level Detail Values

Value	Steps in Log?	Runtime Data Included?	Details Captured
`none`	No	No	Only top-level flow metadata.
`basic`	Yes	No	Name, type, duration, path, and status.
`full`	Yes	Yes	All runtime data (inputs, outputs, connections).

Log Structure

Each log entry follows a consistent schema, allowing for easy parsing by monitoring tools.

Example Schema

{
  "flowName": "get-customer-flow",
  "durationMs": 142,
  "success": true,
  "errorMessage": null,
  "input": { ... },
  "output": { ... },
  "steps": [ ... ]
}

Field Reference

Field	Always Present	Description
`flowName`	Yes	Unique identifier for the flow.
`durationMs`	Yes	Total execution time in milliseconds.
`success`	Yes	`true` if the status code is 2xx.
`errorMessage`	On failure	Detailed exception or error description.
`input`	Optional*	Request metadata (depends on `log-input-output`).
`output`	Optional*	Response metadata (depends on `log-input-output`).
`steps`	Optional**	List of step metadata (depends on `step-level`).

Input & Output Structure

The shape of the input and output objects varies based on the trigger type used to start the flow.

Trigger Type	Input Example	Output Example
HTTP (WebFlux)	Method, URL, ContentType, Origin, Headers, Body	httpCode, Headers, Body
Kafka	Topic, Body	Topic, Body
IBM / ActiveMQ	Queue, Mode, Body	Queue, Body
AS/400 CDC	Tables, Body	N/A
VSAM Dataset	vsamPath, Body	N/A

Note on Data Privacy: When log-input-output is set to false (the default), the body field is always returned as an empty object {}. All other technical metadata (URLs, topics, queues) remains visible for diagnostic purposes.