Logging Guide

Jobmon ships with a structlog-based logging stack that captures telemetry metadata by default while keeping host applications in control of console rendering.

For implementation details, see Logging Architecture.

Key Behaviors

Silent by default – workflow.run() produces no console output unless you explicitly enable logging.
Easy to enable – Use workflow.run(configure_logging=True) to enable console output with sensible defaults.
OTLP telemetry – When configured, workflow metadata is automatically exported to your telemetry backend.
Host-friendly – If your application already configures structlog, Jobmon integrates without disrupting your setup.

Quick Start

Enable Console Logging

The simplest way to see Jobmon logs:

from jobmon.client.api import Tool

tool = Tool("my_tool")
wf = tool.create_workflow("my_workflow")
# ... add tasks ...

wf.run(configure_logging=True)  # Enables console output

Without configure_logging=True, the workflow runs silently (telemetry is still captured if OTLP is configured).

Host Application Integration

If your application already configures structlog, Jobmon adapts automatically:

import structlog

# Your application's structlog configuration
structlog.configure(
    processors=[my_custom_processor, my_renderer],
    wrapper_class=structlog.make_filtering_bound_logger(logging.INFO),
)

from jobmon.client.api import Tool

wf = Tool("my_tool").create_workflow("my_workflow")
wf.run()  # Jobmon adapts to your structlog config

Jobmon prepends its processors to your chain but leaves your renderer in control, so logs appear in your preferred format.

Configuration

Enable OTLP Log Export

Configure OTLP log export in your jobmonconfig.yaml:

telemetry:
  deployment_environment: prod

  logging:
    enabled: true
    log_exporter: http_log

    exporters:
      http_log:
        module: opentelemetry.exporter.otlp.proto.http._log_exporter
        class: OTLPLogExporter
        endpoint: "https://otelcol.example.com/v1/logs"
        timeout: 30

Custom Logconfig File

For advanced customization, provide your own logconfig file:

# In jobmonconfig.yaml
logging:
  client_logconfig_file: "/path/to/custom_logging.yaml"

Example custom logconfig:

# custom_logging.yaml
version: 1
disable_existing_loggers: false

formatters:
  structlog_event_only:
    '()': jobmon.core.config.structlog_formatters.JobmonStructlogEventOnlyFormatter

handlers:
  console:
    class: logging.StreamHandler
    level: INFO
    formatter: structlog_event_only

  otlp:
    class: jobmon.core.otlp.JobmonOTLPLoggingHandler
    level: INFO
    exporter: {}  # Uses telemetry.logging.exporters config

loggers:
  jobmon.client:
    handlers: [console, otlp]
    level: INFO
    propagate: false

FAQ

Why don’t I see any Jobmon logs?: Console logging is disabled by default. Use workflow.run(configure_logging=True) to enable it.
Why are Jobmon logs formatted like my application logs?: Jobmon integrates with your existing structlog configuration, so your formatter controls the output style.
Can I use Jobmon without OTLP?: Yes. OTLP is optional. Without it configured, Jobmon just doesn’t export telemetry—everything else works normally.
My OTLP logs are missing workflow metadata: Ensure telemetry.logging.enabled: true in your jobmonconfig and that the OTLP handler is properly configured on jobmon.* loggers.