DocumentationAdobe PassAdobe Pass Concurrency Monitoring

Handling 409 Conflict Errors handling-409-errors

Last update: Thu Feb 05 2026 00:00:00 GMT+0000 (Coordinated Universal Time)

When a user tries to start a new stream and hits a concurrent usage limit, Concurrency Monitoring returns a 409 Conflict response. Understanding how to handle this error is crucial for providing a good user experience.

What is a 409 Conflict? what-is-a-409-conflict

A 409 Conflict occurs when:

  1. User tries to start a new stream
  2. Policy evaluation determines the request would exceed limits
  3. System returns 409 with detailed conflict information
  4. Application must decide how to handle the conflict

409 Response Structure

{
  "status": "error",
  "error": {
    "code": "POLICY_VIOLATION",
    "message": "Concurrent usage limit exceeded"
  },
  "evaluationResult": {
    "decision": "DENY",
    "associatedAdvice": [
      {
        "id": "advice-1",
        "adviceType": "rule-violation",
        "attributes": {
          "rule": "max_streams",
          "threshold": 3,
          "current": 4,
          "conflicts": [
            {
              "sessionId": "session-123",
              "terminationCode": "term-456",
              "metadata": {
                "deviceId": "device-789",
                "channel": "Channel1",
                "contentType": "live"
              }
            }
          ]
        }
      }
    ]
  }
}

Understanding the Response understanding-the-response

Key Fields

  • decision: Always “DENY” for 409 conflicts
  • associatedAdvice: Array of advice objects explaining the violation
  • conflicts: List of active sessions that are causing the conflict
  • terminationCode: Unique code to terminate a specific session

Advice Types

Rule Violation Advice

{
  "adviceType": "rule-violation",
  "attributes": {
    "rule": "max_streams",
    "threshold": 3,
    "current": 4,
    "conflicts": [...]
  }
}

Remote Termination Advice

{
  "adviceType": "remote-termination",
  "attributes": {
    "terminatedBy": "session-456",
    "reason": "New session requested with X-Terminate header"
  }
}

Handling Strategies handling-strategies

  • In FIFO mode, CM allows the new session to start by terminating an existing one.
  • In LIFO mode, CM blocks the new session and informs the user

Best Practices best-practices

1. Clear User Communication

  • Explain the limit - Users should understand why they’re blocked
  • Show available options - What they can do to resolve the conflict
  • Provide context - Show which sessions are active

2. Graceful Error Handling

  • Don’t crash - Handle 409 errors gracefully
  • Provide alternatives - Offer ways to resolve the conflict
  • Save user state - Don’t lose their content selection

3. User Experience Considerations

  • Quick resolution - Make it easy to resolve conflicts
  • Clear choices - Users should understand their options
  • Consistent behavior - Handle conflicts the same way every time

4. Technical Considerations

  • Parse response carefully - Extract all relevant information
  • Handle edge cases - What if no conflicts are returned?
  • Log conflicts - Track policy violations for analysis
recommendation-more-help
42139a1e-84f9-43e7-9581-d6e1d65973da