Spring Boot Logging Best Practices for BPM Applications

Logging is critical in BPM systems because workflows are long-running, asynchronous, and multi-service.

In a normal web app, you debug a request.
In a BPM system you debug a process instance.

Without proper logging:

• You cannot trace workflow path

• Incidents are hard to diagnose

• External tasks fail silently

• Business teams cannot understand failures

This guide explains production-grade logging for Spring Boot apps integrated with BPM engines like Camunda Platform.

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📌 Why BPM Logging Is Different

BPM applications involve:

• Workflow engine

• Workers

• External services

• Human tasks

• Message events

A single business transaction may span hours or days.

So we must log by Process Instance, not HTTP request.

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🖼️ BPM Logging Architecture

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🧠 Core Principle: Correlation ID Logging

Every process instance must carry a trace ID.

Use:
processInstanceKey or businessKey

Example log:

[ORDER-92812] Payment authorized
[ORDER-92812] Invoice generated
[ORDER-92812] Email sent

Now you can trace entire workflow.

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🛠 Step 1: Add Correlation ID Filter

@Component
public class LoggingFilter extends OncePerRequestFilter {

    @Override
    protected void doFilterInternal(HttpServletRequest request,
                                    HttpServletResponse response,
                                    FilterChain chain)
            throws ServletException, IOException {

        String correlationId = UUID.randomUUID().toString();
        MDC.put("cid", correlationId);

        chain.doFilter(request, response);
        MDC.clear();
    }
}

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🛠 Step 2: Configure Log Pattern

application.yml

logging:
  pattern:
    level: "%5p [${spring.application.name:},%X{cid}]"

Now every log prints correlation id.

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🛠 Step 3: Propagate BPM Variables

In worker:

String businessKey = externalTask.getBusinessKey();
MDC.put("cid", businessKey);

Now logs map to workflow.

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🖼️ Log Trace Example

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🔁 Logging Levels Strategy

Level	Usage
INFO	Business events
DEBUG	Technical details
WARN	Recoverable issues
ERROR	Incidents

Example:

INFO  Order submitted
INFO  Payment requested
WARN  Payment retry 2
ERROR Payment failed after retries

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🛠 Step 4: Structured JSON Logging (Recommended)

Use JSON logs for observability tools.

Add dependency:

<artifactId>logstash-logback-encoder</artifactId>

logback-spring.xml

<encoder class="net.logstash.logback.encoder.LogstashEncoder"/>

Now logs integrate with ELK / Grafana.

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🔐 What To Log in BPM Apps

Always log:

✔ process start
✔ task completion
✔ retries
✔ incidents
✔ external API calls

Avoid logging:

❌ sensitive data
❌ full payloads
❌ passwords

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⚠️ Common Mistakes

❌ Logging without business key
❌ Using DEBUG in production
❌ Logging entire JSON payload
❌ Missing retry logs

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🏆 Production Best Practices

✔ Use correlation id
✔ Centralized log storage
✔ Structured logging
✔ Separate business vs technical logs
✔ Monitor incidents

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🎯 Example BPM Log Flow

[ORDER-1001] Process started
[ORDER-1001] Payment requested
[ORDER-1001] Payment success
[ORDER-1001] Shipping triggered
[ORDER-1001] Process completed

Readable for both dev & business teams.

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🎯 Conclusion

Good logging turns BPM systems from:

❌ Black box → ✅ Observable system

With proper correlation and structured logs, diagnosing production issues becomes fast and reliable.

💼 Professional Support Available

If you are facing issues in real projects related to enterprise backend development or workflow automation, I provide paid consulting, production debugging, project support, and focused trainings.

Technologies covered include Java, Spring Boot, PL/SQL, Azure, CMS and workflow automation (jBPM, Camunda BPM, RHPAM).

📧 Contact: ishikhanirankari@gmail.com | info@realtechnologiesindia.com

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