Troubleshoot OAuth/OIDC Issues on Confluent Cloud

This guide helps you diagnose and resolve common OAuth/OIDC authentication issues when connecting to Confluent Cloud.

Common issues and solutions

Authentication failures

Symptoms

  • Client fails to connect with authentication errors
  • Invalid credentials or Authentication failed messages
  • Connection timeouts during authentication

Common causes and solutions

  1. Invalid client credentials

    Cause: Incorrect client ID or client secret

    Solution: - Verify client ID and secret match your identity provider configuration - Check for typos or extra whitespace in credentials - Ensure credentials are properly URL-encoded if needed

    Debug Steps: - Enable debug logging to see the exact credentials being sent - Test credentials directly with your identity provider’s token endpoint

  2. Incorrect token endpoint URL

    Cause: Wrong or inaccessible OAuth token endpoint

    Solution:

    • Verify the token endpoint URL is correct and accessible
    • Check network connectivity to the endpoint
    • Ensure the endpoint supports the client_credentials grant type

    Debug steps:

    • Test the endpoint with curl or Postman
    • Check firewall rules and network access

  3. Token expiration issues

    Cause: Tokens expiring before refresh or invalid expiration handling

    Solution:

    • Implement proper token refresh logic
    • Set appropriate buffer time before token expiration
    • Monitor token lifecycle and refresh cycles

    Debug steps: - Check token expiration times in JWT payload - Verify refresh logic is working correctly

Network and connectivity issues

Symptoms:

  • Connection timeouts
  • Network unreachable errors
  • SSL/TLS handshake failures

Common causes and solutions:

  1. Firewall or network restrictions

    Cause: Network policies blocking OAuth endpoint access

    Solution: - Configure firewall rules to allow access to OAuth endpoints - Check corporate proxy settings - Verify DNS resolution for OAuth domains

    Debug Steps: - Test connectivity with ping, telnet, or curl - Check network logs for blocked connections

  2. SSL/TLS certificate issues

    Cause: Invalid or expired SSL certificates on OAuth endpoints

    Solution: - Verify SSL certificate validity - Update certificate authorities if needed - Check for certificate chain issues

    Debug Steps: - Test SSL connection with openssl - Check certificate expiration dates

  3. DNS resolution problems

    Cause: Unable to resolve OAuth endpoint hostnames

    Solution: - Verify DNS configuration - Check for DNS caching issues - Ensure proper hostname resolution

    Debug Steps: - Test DNS resolution with nslookup or dig - Check /etc/hosts file for incorrect entries

Configuration issues

Symptoms: - Configuration parsing errors - Missing required parameters - Invalid parameter values

Common causes and solutions:

  1. Missing required parameters

    Cause: Incomplete OAuth configuration

    Solution: - Ensure all required parameters are specified - Check parameter names and values - Verify logical cluster ID and identity pool ID

    Debug Steps: - Review configuration against parameter reference - Check for typos in parameter names

  2. Invalid parameter values

    Cause: Incorrect parameter formats or values

    Solution: - Verify parameter value formats - Check for proper URL encoding - Ensure boolean values are correct

    Debug Steps: - Validate parameter values against expected formats - Check for encoding issues

  3. JAAS configuration errors

    Cause: Malformed JAAS configuration string

    Solution: - Verify JAAS configuration syntax - Check for proper escaping of special characters - Ensure all required JAAS parameters are present

    Debug Steps: - Parse JAAS configuration manually - Check for syntax errors

Identity provider issues

Symptoms: - Identity provider authentication failures - Incorrect token claims or scopes - Authorization denied errors

Common causes and solutions:

  1. Incorrect identity provider configuration

    Cause: Mismatch between client and identity provider settings

    Solution: - Verify identity provider configuration - Check client registration settings - Ensure proper redirect URIs and scopes

    Debug Steps: - Review identity provider logs - Check client registration details

  2. Token claim issues

    Cause: Missing or incorrect JWT claims

    Solution: - Verify required claims are present in tokens - Check claim values and formats - Ensure proper audience and issuer values

    Debug Steps: - Decode and inspect JWT tokens - Verify claim values against expectations

  3. Scope and permission issues

    Cause: Insufficient permissions or incorrect scopes

    Solution: - Verify required scopes are requested - Check identity provider permission settings - Ensure proper role assignments

    Debug Steps: - Check token scope values - Verify identity provider permissions

Debugging techniques

Enable debug logging

Java client debug logging:

// Enable SASL debug logging
System.setProperty("sun.security.krb5.debug", "true");
System.setProperty("javax.security.auth.debug", "true");

// Enable Kafka client debug logging
props.put("log4j.logger.org.apache.kafka", "DEBUG");
props.put("log4j.logger.org.apache.kafka.common.security", "DEBUG");

Python client debug logging:

import logging

# Enable librdkafka debug logging
logging.basicConfig(level=logging.DEBUG)

# Enable OAuth callback debugging
def debug_oauth_callback(args, config):
    print(f"OAuth callback called with args: {args}")
    # ... rest of callback implementation

C# client debug logging:

// Enable debug logging
var config = new ProducerConfig
{
    // ... other config
    Debug = "all"  // Enable all debug categories
};

Token inspection

Decode JWT tokens:

import jwt
import json

def inspect_token(token):
    """Decode and inspect JWT token."""
    try:
        # Decode without verification for inspection
        decoded = jwt.decode(token, options={"verify_signature": False})
        print("Token Header:", json.dumps(decoded['header'], indent=2))
        print("Token Payload:", json.dumps(decoded['payload'], indent=2))
        return decoded
    except Exception as e:
        print(f"Error decoding token: {e}")
        return None

Check token expiration:

import time

def check_token_expiration(token_data):
    """Check if token is expired or near expiration."""
    exp = token_data.get('exp')
    if exp:
        current_time = int(time.time())
        time_until_expiry = exp - current_time
        print(f"Token expires in {time_until_expiry} seconds")
        return time_until_expiry > 300  # 5 minute buffer
    return False

Network diagnostics

Test OAuth endpoint connectivity:

# Test basic connectivity
curl -I https://your-oauth-endpoint.com/oauth2/token

# Test token endpoint with credentials
curl -X POST https://your-oauth-endpoint.com/oauth2/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials&client_id=your-client-id&client_secret=your-client-secret"

Check SSL certificate:

# Check SSL certificate
openssl s_client -connect your-oauth-endpoint.com:443 -servername your-oauth-endpoint.com

# Check certificate chain
openssl s_client -connect your-oauth-endpoint.com:443 -showcerts

DNS resolution:

# Check DNS resolution
nslookup your-oauth-endpoint.com
dig your-oauth-endpoint.com

# Check for DNS issues
traceroute your-oauth-endpoint.com

Error analysis

Common error messages and solutions:

  1. “Invalid credentials”
    • Check client ID and secret
    • Verify identity provider configuration
    • Ensure proper URL encoding
  2. “Token endpoint not found”
    • Verify token endpoint URL
    • Check network connectivity
    • Ensure endpoint supports client_credentials grant
  3. “Token expired”
    • Implement proper token refresh
    • Check token expiration handling
    • Monitor token lifecycle
  4. “Invalid token format”
    • Verify JWT token structure
    • Check token encoding
    • Validate token claims
  5. “Authorization denied”
    • Check identity pool configuration
    • Verify token claims match pool filters
    • Ensure proper permissions

Monitoring and alerting

Key metrics to monitor:

  1. Authentication success rate
    • Track successful vs failed authentication attempts
    • Monitor authentication latency
    • Alert on authentication failures
  2. Token refresh cycles
    • Monitor token refresh frequency
    • Track token expiration times
    • Alert on token refresh failures
  3. Network connectivity
    • Monitor OAuth endpoint availability
    • Track connection latency
    • Alert on connectivity issues
  4. Error rates
    • Monitor authentication error types
    • Track configuration errors
    • Alert on increased error rates

Recommended alerts:

  • Authentication failure rate > 5%
  • Token refresh failure rate > 1%
  • OAuth endpoint response time > 5 seconds
  • Network connectivity failures
  • Configuration parsing errors

Log analysis:

# Search for authentication errors
grep "authentication failed" kafka-client.log

# Search for token refresh issues
grep "token refresh" kafka-client.log

# Search for network errors
grep "connection timeout" kafka-client.log

Getting help

If you’re unable to resolve OAuth issues using this troubleshooting guide:

  1. Collect diagnostic information:
    • Enable debug logging
    • Gather error messages and logs
    • Document configuration settings
    • Note the exact steps to reproduce the issue
  2. Check documentation:
    • Review identity provider documentation
    • Consult Confluent Cloud OAuth documentation
    • Check for known issues or limitations
  3. Contact support:
    • Provide detailed error information
    • Include relevant logs and configuration
    • Describe the troubleshooting steps already taken
  4. Community resources:
    • Check Confluent Community forums
    • Review GitHub issues for similar problems
    • Consult OAuth/OIDC community resources

Information to include in support requests:

  • Client type and version (Java, Python, C#, etc.)
  • Identity provider type and version
  • Complete error messages and stack traces
  • Relevant configuration (with sensitive data redacted)
  • Steps to reproduce the issue
  • Debug logs and token inspection results
  • Network connectivity test results