Error Catalog

Error Catalog

Comprehensive catalog of all platform error codes with causes, examples, and resolution steps.

Table of Contents

• Handler Discovery Errors
• Authentication & Authorization Errors
• Contract Validation Errors
• Message Bus Errors
• Event Store Errors
• Read Model Errors
• CQRS Errors
• Domain Modeling Errors
• Client System Errors
• Service Discovery Errors
• SSE Errors

---

Handler Discovery Errors

HANDLER_NOT_FOUND

Error Code: HANDLER_NOT_FOUND

Error Message:

No handler registered for message type: CreateUserCommand

Cause:

• Handler class not discovered during service startup
• Handler not in correct folder (/commands/, /queries/, /events/)
• Missing @CommandHandler, @QueryHandler, or @EventHandler decorator
• Handler class not exported from module

Example:

// ❌ WRONG: Missing decorator
export class CreateUserHandler {
  async handle(command: CreateUserCommand) {
    // ...
  }
}

// ✓ CORRECT: With decorator
@CommandHandler(CreateUserCommand)
export class CreateUserHandler {
  async handle(command: CreateUserCommand) {
    // ...
  }
}

Solution:

1. Ensure handler has correct decorator
2. Place handler file in correct folder:
   • Commands: /src/commands/SomethingHandler.ts
   • Queries: /src/queries/SomethingHandler.ts
   • Events: /src/events/SomethingHandler.ts
3. Verify handler is exported: export class CreateUserHandler
4. Check service logs for handler discovery messages

Quick Fix:

# Check handler discovery logs
grep "Discovered.*Handler" service.log

# Verify folder structure
ls -R src/commands src/queries src/events

Related:

• Handler Discovery Pattern

---

Authentication & Authorization Errors

AUTHORIZATION_ERROR (Layer 1)

Error Code: AUTHORIZATION_ERROR

Error Message:

Access denied to operation 'CreateUser'. Required permissions: [users:create],
User permissions: [users:read]

Cause:

• User lacks required permissions at API Gateway level
• JWT token missing required permission claims
• Permission decorator requires permissions user doesn’t have

Example:

@CommandHandler(CreateUserCommand)
@RequiresPermissions(['users:create'])
export class CreateUserHandler {
  // User needs 'users:create' permission
}

Solution:

1. Verify user has required permissions in JWT token
2. Check permission requirements in handler decorator
3. Grant required permissions to user/role in auth service
4. Verify permission format matches exactly (case-sensitive)

Quick Fix:

# Decode JWT token to check permissions
echo "YOUR_JWT_TOKEN" | base64 -d | jq '.permissions'

# Check handler permission requirements
grep "@RequiresPermissions" src/commands/CreateUserHandler.ts

---

POLICY_VIOLATION (Layer 2)

Error Code: POLICY_VIOLATION

Error Message:

Policy 'OwnershipPolicy' violation for user 'user-123' on operation 'UpdateUser':
User can only update their own profile

Cause:

• User failed policy-based authorization check
• Business rule violation (e.g., editing someone else’s resource)
• Policy logic returned false for current user

Example:

@CommandHandler(UpdateUserCommand)
@RequiresPermissions(['users:update'])
export class UpdateUserHandler {
  async handle(command: UpdateUserCommand, context: ExecutionContext) {
    // Layer 2: Policy check
    if (command.userId !== context.user.userId && !context.user.isAdmin) {
      throw new PolicyViolationError(
        'OwnershipPolicy',
        context.user.userId,
        'UpdateUser',
        'User can only update their own profile'
      );
    }
  }
}

Solution:

1. Review policy violation reason in error message
2. Verify user meets business rule requirements
3. Check if user needs admin/special role for operation
4. Validate command parameters match user context

Quick Fix:

// Add policy check logging
console.log('Policy check:', {
  userId: context.user.userId,
  targetUserId: command.userId,
  isAdmin: context.user.isAdmin
});

---

POLICY_AUTH_REQUIRED

Error Code: POLICY_AUTH_REQUIRED

Error Message:

Authentication required: Operation requires authenticated user

Cause:

• Handler requires authentication but user is not authenticated
• JWT token missing or invalid
• Anonymous access attempted on protected operation

Solution:

1. Include JWT token in request
2. Verify token is valid and not expired
3. Check if operation allows anonymous access
4. Refresh expired token

---

POLICY_PERMISSION_DENIED

Error Code: POLICY_PERMISSION_DENIED

Error Message:

Insufficient permissions for UpdateUser.
Required: users:update OR users:admin, Actual: users:read

Cause:

• User lacks any of the required permissions for policy check
• Policy requires at least one permission from list

Solution:

1. Grant one of the required permissions to user
2. Review policy permission requirements
3. Verify permission names match exactly

---

Contract Validation Errors

CONTRACT_VALIDATION_ERROR

Error Code: CONTRACT_VALIDATION_ERROR

Error Message:

Contract validation failed for service 'user-service': Invalid input schema

Cause:

• Contract input/output schema invalid
• Missing required contract fields
• Type definition errors in contract

Example:

// ❌ WRONG: Missing input schema
export const CreateUserCommand = {
  messageType: 'CreateUserCommand',
  // Missing: inputSchema
};

// ✓ CORRECT: Complete contract
export const CreateUserCommand = {
  messageType: 'CreateUserCommand',
  inputSchema: {
    email: 'string',
    password: 'string'
  },
  outputSchema: {
    userId: 'string'
  }
};

Solution:

1. Ensure contract has valid inputSchema and outputSchema
2. Use TypeScript types for compile-time validation
3. Verify all required fields present in schema
4. Check contract syntax matches platform requirements

Quick Fix:

// Validate contract structure
const contract = {
  messageType: 'CreateUserCommand',
  inputSchema: { /* ... */ },
  outputSchema: { /* ... */ },
  requiredPermissions: ['users:create']
};

---

PERMISSION_VALIDATION_ERROR

Error Code: PERMISSION_VALIDATION_ERROR

Error Message:

Invalid permission format: 'users-create' (must use 'resource:action' format)

Cause:

• Permission string doesn’t match required format
• Missing colon separator in permission
• Invalid characters in permission string

Solution:

1. Use format: resource:action (e.g., users:create)
2. Lowercase resource and action names
3. Verify permission names in contract declarations

Quick Fix:

// ❌ WRONG
@RequiresPermissions(['users-create', 'USERS:DELETE'])

// ✓ CORRECT
@RequiresPermissions(['users:create', 'users:delete'])

---

SCHEMA_GENERATION_ERROR

Error Code: SCHEMA_GENERATION_ERROR

Error Message:

Failed to generate GraphQL schema: Duplicate type name 'User'

Cause:

• Type name conflicts in schema generation
• Invalid GraphQL type definitions
• Circular type references

Solution:

1. Ensure unique type names across contracts
2. Check for naming conflicts in domain types
3. Review GraphQL schema generation logs
4. Use type aliases to resolve conflicts

---

Message Bus Errors

MESSAGE_BUS_ERROR

Error Code: MESSAGE_BUS_ERROR

Error Message:

Message bus operation 'publish' failed: Connection closed

Cause:

• RabbitMQ connection lost
• Network issues between service and message bus
• Message bus server unavailable
• Connection timeout

Solution:

1. Check RabbitMQ server status
2. Verify network connectivity
3. Review connection configuration
4. Check for firewall/proxy issues
5. Verify credentials and vhost access

Quick Fix:

# Check RabbitMQ status
docker ps | grep rabbitmq

# Test connection
curl http://localhost:15672/api/overview

# Check logs
docker logs rabbitmq

---

CIRCUIT_BREAKER_OPEN

Error Code: CIRCUIT_BREAKER_OPEN

Error Message:

Circuit breaker is open for service 'user-service' after 5 failures

Cause:

• Service has failed repeatedly
• Circuit breaker protecting against cascade failures
• Target service unhealthy or unavailable

Solution:

1. Wait for circuit breaker to reset (half-open state)
2. Fix underlying service issues causing failures
3. Check target service health
4. Review circuit breaker configuration

Quick Fix:

// Circuit breaker will auto-reset after timeout
// Check circuit breaker status in logs
[CircuitBreaker] State transition: open -> half-open

Related:

• Circuit Breaker Pattern

---

RETRY_EXHAUSTED

Error Code: RETRY_EXHAUSTED

Error Message:

Operation 'SendEmail' failed after 3 retry attempts: SMTP connection refused

Cause:

• All retry attempts failed
• Persistent error condition
• Target service consistently unavailable

Solution:

1. Fix underlying error causing failures
2. Check target service availability
3. Review retry policy configuration
4. Investigate root cause of repeated failures

Quick Fix:

// Adjust retry policy
const retryPolicy = {
  maxAttempts: 5,
  initialDelayMs: 1000,
  maxDelayMs: 30000,
  backoffMultiplier: 2
};

---

REQUEST_TIMEOUT

Error Code: REQUEST_TIMEOUT

Error Message:

Operation 'GetUser' timed out after 5000ms

Cause:

• Target service too slow to respond
• Network latency issues
• Service overloaded
• Timeout configured too low

Solution:

1. Increase timeout if operation legitimately slow
2. Optimize slow handler logic
3. Check service performance metrics
4. Review database query performance

Quick Fix:

// Adjust timeout
await queryBus.execute(new GetUserQuery(userId), {
  timeout: 10000 // 10 seconds
});

---

OPERATION_TIMEOUT

Error Code: OPERATION_TIMEOUT

Error Message:

query 'GetUserQuery' timed out after 5000ms

Cause:

• Query handler execution too slow
• Database query performance issues
• Network latency to dependencies
• Timeout value too low for operation complexity

Solution:

1. Optimize query handler performance
2. Add database indexes for query
3. Increase timeout for complex operations
4. Review query execution plan

---

Event Store Errors

EVENT_STORE_ERROR

Error Code: EVENT_STORE_ERROR

Error Message:

Failed to save aggregate user-123: Database connection lost

Cause:

• Database connection issues
• Event serialization failures
• Concurrency conflicts
• Database constraints violated

Solution:

1. Check PostgreSQL database status
2. Verify database connectivity
3. Review event data for serialization issues
4. Check for concurrent updates to same aggregate

Quick Fix:

# Check PostgreSQL status
pg_isready -h localhost -p 5432

# Check connections
psql -c "SELECT count(*) FROM pg_stat_activity;"

# Review recent errors
tail -f postgresql.log

---

AGGREGATE_CONCURRENCY_ERROR

Error Code: AggregateConcurrencyError

Error Message:

Concurrency conflict for aggregate user-123.
Expected version 5, but actual version is 6

Cause:

• Multiple commands modifying same aggregate concurrently
• Optimistic locking conflict
• Command executed against stale aggregate version

Example:

// Two concurrent updates to same user
// First update succeeds, second fails with concurrency error
await commandBus.execute(new UpdateUserEmailCommand(userId, 'new1@example.com'));
await commandBus.execute(new UpdateUserEmailCommand(userId, 'new2@example.com'));

Solution:

1. Retry the command to load latest version
2. Implement retry logic for concurrency conflicts
3. Review command ordering and execution patterns
4. Consider using saga for coordinated updates

Quick Fix:

// Auto-retry on concurrency error
try {
  await commandBus.execute(command);
} catch (error) {
  if (error instanceof AggregateConcurrencyError) {
    // Reload aggregate and retry
    await commandBus.execute(command);
  }
}

---

AGGREGATE_NOT_FOUND

Error Code: AggregateNotFoundError

Error Message:

User with ID user-123 not found

Cause:

• Aggregate ID doesn’t exist in event store
• Attempting to load non-existent aggregate
• Typo in aggregate ID
• Aggregate deleted or never created

Solution:

1. Verify aggregate ID is correct
2. Check if aggregate was created successfully
3. Use exists check before loading
4. Handle not found case in application logic

Quick Fix:

// Check if aggregate exists first
const exists = await aggregateAccess.exists(userId);
if (!exists) {
  throw new NotFoundError('User', userId);
}

const user = await aggregateAccess.getById(userId);

---

AGGREGATE_OPERATION_ERROR

Error Code: AggregateOperationError

Error Message:

Failed to apply event UserCreated to aggregate user-123

Cause:

• Error in event application logic
• Invalid event data
• Event handler throwing exception
• State transition validation failure

Solution:

1. Review event handler implementation
2. Validate event data structure
3. Check business rule violations
4. Add error handling in event handlers

---

Read Model Errors

ReadModelBase not initialized

Error Message:

ReadModelBase not initialized. Call ReadModelBase.initialize() first.

Cause:

• Read model base class not initialized with database config
• Missing initialization call during service startup

Solution:

import { ReadModelBase } from '@banyanai/platform-event-sourcing';

// Initialize before using read models
ReadModelBase.initialize(dbConfig, 'my-service');

Quick Fix: Add initialization to service startup:

await BaseService.start({ /* ... */ });
ReadModelBase.initialize(config.database, config.serviceName);

Related:

• Read Model Issues

---

Projections table not found

Error Message:

Projections table not found in public schema.
Ensure PostgresEventStore.initializeSchema() has been called first.

Cause:

• Event store schema not initialized
• Database migrations not run
• Wrong database selected

Solution:

// Initialize event store schema BEFORE read models
const eventStore = new PostgresEventStore(dbConfig);
await eventStore.initializeSchema();

// Then initialize read models
await readModelManager.initialize([UserReadModel]);

Quick Fix:

-- Manually create projections table
CREATE TABLE IF NOT EXISTS projections (
  id TEXT NOT NULL,
  projection_name TEXT NOT NULL,
  data JSONB NOT NULL,
  version INTEGER NOT NULL DEFAULT 1,
  created_at TIMESTAMP DEFAULT NOW(),
  updated_at TIMESTAMP DEFAULT NOW(),
  PRIMARY KEY (id, projection_name)
);

CREATE INDEX IF NOT EXISTS idx_projections_name ON projections(projection_name);
CREATE INDEX IF NOT EXISTS idx_projections_data ON projections USING GIN (data);

---

Failed to persist projection

Error Message:

Failed to persist projection user_read_model.email for aggregate user-123:
duplicate key value violates unique constraint "idx_user_email"

Cause:

• Unique constraint violation
• Duplicate data in projection
• Event replay creating duplicates

Solution:

1. Check for duplicate records in projections table
2. Review unique indexes on read model
3. Ensure projection handlers are idempotent
4. Clean up duplicate data before replay

Quick Fix:

-- Find duplicates
SELECT data->>'email', COUNT(*)
FROM projections
WHERE projection_name = 'user_read_model'
GROUP BY data->>'email'
HAVING COUNT(*) > 1;

-- Remove duplicates (keep newest)
DELETE FROM projections p1
WHERE projection_name = 'user_read_model'
  AND EXISTS (
    SELECT 1 FROM projections p2
    WHERE p2.projection_name = p1.projection_name
      AND p2.data->>'email' = p1.data->>'email'
      AND p2.updated_at > p1.updated_at
  );

Related:

• Read Model Issues - Projection Failures

---

CQRS Errors

VALIDATION_ERROR

Error Code: VALIDATION_ERROR (CQRS)

Error Message:

Validation failed for fields: email, password

Cause:

• Command or query input validation failed
• Required fields missing
• Field values don’t meet constraints

Example:

// Validation error with field details
throw new CQRSValidationError(
  'Validation failed',
  correlationId,
  [
    { field: 'email', message: 'Invalid email format', value: 'not-an-email' },
    { field: 'password', message: 'Password too short', value: '123' }
  ]
);

Solution:

1. Verify all required fields provided
2. Check field value constraints
3. Review validation rules in handler
4. Ensure input data types match schema

Quick Fix:

// Client-side validation before sending
function validateCreateUser(input: CreateUserInput) {
  const errors = [];

  if (!input.email || !input.email.includes('@')) {
    errors.push({ field: 'email', message: 'Valid email required' });
  }

  if (!input.password || input.password.length < 8) {
    errors.push({ field: 'password', message: 'Password must be at least 8 characters' });
  }

  return errors;
}

---

UNKNOWN_ERROR

Error Code: UNKNOWN_ERROR

Error Message:

An unknown error occurred

Cause:

• Unexpected exception in handler
• Unhandled error type
• Error not properly wrapped

Solution:

1. Check service logs for full error details
2. Add proper error handling in handler
3. Wrap errors in domain-specific error types
4. Review stack trace for root cause

---

Domain Modeling Errors

DOMAIN_ERROR

Error Message:

Cannot send invoice with no line items

Cause:

• Business rule violation in domain logic
• Invalid state transition
• Precondition not met

Example:

@AggregateRoot()
class Invoice {
  send() {
    if (this.lineItems.length === 0) {
      throw new DomainError('Cannot send invoice with no line items');
    }

    if (this.status !== 'draft') {
      throw new DomainError('Can only send draft invoices');
    }

    // Apply business logic
  }
}

Solution:

1. Review business rule that was violated
2. Ensure aggregate in correct state before operation
3. Validate preconditions met
4. Check domain invariants

---

DOMAIN_ASSERTION_FAILED

Error Code: DOMAIN_ASSERTION_FAILED

Error Message:

Assertion failed: Amount must be positive

Cause:

• Domain assertion check failed
• Invariant violation
• Invalid argument to domain method

Solution:

1. Review assertion requirements
2. Validate input parameters
3. Check domain constraints
4. Ensure valid state before operation

---

Client System Errors

SERVICE_UNAVAILABLE

Error Code: SERVICE_UNAVAILABLE

Error Message:

user-service: Service is currently unavailable

Cause:

• Target service not running
• Service not registered in service discovery
• Network connectivity issues
• Service in unhealthy state

Solution:

1. Check if target service is running
2. Verify service discovery registration
3. Check service health endpoint
4. Review service logs for errors

Quick Fix:

# Check service status
docker ps | grep user-service

# Check service discovery
curl http://localhost:3001/health

# Restart service
docker restart user-service

---

SERVICE_DEGRADED

Error Code: SERVICE_DEGRADED

Error Message:

user-service: Service is operating in degraded mode

Cause:

• Service partially functional
• Some dependencies unavailable
• Performance degradation
• Resource constraints

Solution:

1. Check service health metrics
2. Review dependency status
3. Monitor resource usage
4. Consider graceful degradation in calling code

---

CLIENT_GENERATION_FAILED

Error Code: CLIENT_GENERATION_FAILED

Error Message:

Client generation failed for service 'user-service' at step 'type-generation':
Invalid type definition

Cause:

• Contract type definitions invalid
• Code generation errors
• TypeScript compilation failures

Solution:

1. Review contract definitions
2. Check type generation logs
3. Validate TypeScript syntax
4. Ensure all types properly exported

---

CONTRACT_VIOLATION

Error Code: CONTRACT_VIOLATION

Error Message:

Contract violation in operation 'CreateUser':
Response missing required field 'userId'

Cause:

• Handler returned data not matching output schema
• Missing required fields in response
• Type mismatch between handler and contract

Solution:

1. Verify handler return type matches output schema
2. Ensure all required fields included in response
3. Check contract definition accuracy
4. Add runtime validation in handler

Quick Fix:

// Ensure response matches contract
@CommandHandler(CreateUserCommand)
export class CreateUserHandler {
  async handle(command: CreateUserCommand): Promise<CreateUserResult> {
    const userId = await this.createUser(command);

    // ✓ Return matches output schema
    return {
      userId, // Required field
      email: command.email
    };
  }
}

---

CORRELATION_CONTEXT_MISSING

Error Code: CORRELATION_CONTEXT_MISSING

Error Message:

Correlation context not available for operation 'CreateUser'

Cause:

• AsyncLocalStorage context not set
• Context lost during async operation
• Missing context propagation

Solution:

1. Ensure operation called within async context
2. Check context propagation through async boundaries
3. Verify BaseService initialized correctly
4. Review async middleware setup

---

Service Discovery Errors

SERVICE_NOT_REGISTERED

Error Message:

Service 'user-service' not found in service discovery

Cause:

• Service not started
• Service discovery registration failed
• Service name mismatch
• Service crashed before registration

Solution:

1. Start the service
2. Check service discovery logs
3. Verify service name configuration
4. Review service health checks

Quick Fix:

# Check registered services
curl http://localhost:3001/api/services | jq '.services[].name'

# Restart service to re-register
docker restart user-service

---

CONTRACT_NOT_FOUND

Error Message:

No contracts found for service 'user-service'

Cause:

• Service started but contracts not broadcast
• Contract registration failed
• Service discovery not receiving contracts

Solution:

1. Check service logs for contract broadcasting
2. Verify message bus connectivity
3. Ensure contracts properly exported
4. Review service discovery subscription

---

SSE Errors

SSE_CONNECTION_UNAUTHORIZED

HTTP Status: 401 Unauthorized

Error Message:

{
  "error": "Unauthorized",
  "message": "Authentication required for SSE connection"
}

Cause:

• No JWT token provided
• Invalid JWT token
• Token expired

Solution:

1. Include JWT token in request:
   • Query param: ?token=YOUR_JWT_TOKEN
   • Header: Authorization: Bearer YOUR_JWT_TOKEN
2. Refresh expired token
3. Verify token format and signature

Quick Fix:

// Include token in connection
const token = localStorage.getItem('jwt');
const eventSource = new EventSource(`/api/events?token=${token}`);

---

SSE_CONNECTION_FORBIDDEN

HTTP Status: 403 Forbidden

Error Message:

{
  "error": "Forbidden",
  "message": "Insufficient permissions for requested event types",
  "deniedEvents": ["AdminEvent", "SystemEvent"]
}

Cause:

• User lacks permissions for requested event types
• Subscription to protected events without authorization

Solution:

1. Subscribe to events user has permissions for
2. Grant required permissions to user
3. Filter event types based on user permissions

Quick Fix:

// Subscribe only to allowed events
const eventSource = new EventSource(
  `/api/events?token=${token}&events=UserCreated,OrderPlaced`
);

---

SSE_CONNECTION_LIMIT

HTTP Status: 503 Service Unavailable

Error Message:

{
  "error": "Service Unavailable",
  "message": "Connection limit exceeded. Please close existing connections."
}

Cause:

• User exceeded maximum concurrent connections (default: 5)
• Browser tabs with open SSE connections
• Connections not properly closed

Solution:

1. Close unused SSE connections
2. Implement proper cleanup on page unload
3. Limit connections per user session
4. Configure higher connection limit if needed

Quick Fix:

// Close connection on page unload
window.addEventListener('beforeunload', () => {
  eventSource.close();
});

// Track and limit connections
const connections = new Set();
function createSSE() {
  if (connections.size >= 3) {
    console.warn('Maximum connections reached');
    return;
  }

  const es = new EventSource('/api/events');
  connections.add(es);

  es.addEventListener('close', () => {
    connections.delete(es);
  });
}

---

Error Handling Best Practices

1. Always Include Correlation ID

import { getCorrelationId } from '@banyanai/platform-core';

try {
  await commandBus.execute(command);
} catch (error) {
  const correlationId = getCorrelationId(error) || 'unknown';
  console.error(`Error processing command [${correlationId}]:`, error);
}

2. Wrap External Errors

try {
  await externalApi.call();
} catch (error) {
  throw new RemoteOperationError(
    'Failed to call external API',
    correlationId,
    'external-service',
    error
  );
}

3. Log Context with Errors

catch (error) {
  Logger.error('Command execution failed', error, {
    commandType: command.constructor.name,
    userId: context.user.userId,
    correlationId: context.correlationId,
    timestamp: new Date().toISOString()
  });
}

4. Return Appropriate HTTP Status

// In API Gateway error handler
if (error instanceof CQRSValidationError) {
  return { status: 400, body: { error: 'Validation failed', details: error.validationErrors } };
}

if (error instanceof CQRSAuthorizationError) {
  return { status: 403, body: { error: 'Access denied' } };
}

if (error instanceof NotFoundError) {
  return { status: 404, body: { error: 'Resource not found' } };
}

// Default to 500 for unexpected errors
return { status: 500, body: { error: 'Internal server error' } };

5. Implement Retry Logic for Transient Errors

import { RetryManager } from '@banyanai/platform-message-bus-client';

const retryManager = new RetryManager({
  maxAttempts: 3,
  initialDelayMs: 1000,
  maxDelayMs: 10000,
  backoffMultiplier: 2
});

await retryManager.executeWithRetry(
  async () => await messageBus.publish(event),
  {
    operation: 'publishEvent',
    serviceName: 'user-service',
    correlationId
  }
);

Error Code Quick Reference

Code	Category	Severity	Action
HANDLER_NOT_FOUND	Discovery	Error	Check handler registration
AUTHORIZATION_ERROR	Auth	Error	Grant permissions
POLICY_VIOLATION	Auth	Error	Review business rules
VALIDATION_ERROR	Input	Error	Fix input data
CONTRACT_VALIDATION_ERROR	Contract	Error	Fix contract definition
MESSAGE_BUS_ERROR	Infrastructure	Error	Check RabbitMQ
CIRCUIT_BREAKER_OPEN	Resilience	Warning	Wait or fix service
RETRY_EXHAUSTED	Resilience	Error	Fix underlying issue
REQUEST_TIMEOUT	Performance	Error	Optimize or increase timeout
EVENT_STORE_ERROR	Storage	Error	Check PostgreSQL
AGGREGATE_CONCURRENCY_ERROR	Concurrency	Warning	Retry operation
AGGREGATE_NOT_FOUND	Data	Error	Verify ID exists
SERVICE_UNAVAILABLE	Discovery	Error	Start service
SERVICE_DEGRADED	Health	Warning	Monitor service
DOMAIN_ERROR	Business Logic	Error	Check business rules

Related Documentation

• Read Model Issues
• Message Bus Issues
• Error Handling Patterns
• Monitoring & Debugging

Getting Help

If you encounter an error not listed here:

1. Check service logs for detailed error messages and stack traces
2. Search codebase for error message
3. Review related component documentation
4. Check issue tracker for similar errors
5. File a detailed bug report with:
   • Error message and code
   • Steps to reproduce
   • Service logs
   • Configuration details
   • Expected vs actual behavior