Tenancy Laravel Package

Technical Evaluation

Architecture Fit

• Multi-tenancy Pattern: The package implements database-per-tenant isolation with minimal code changes, aligning with Laravel’s ecosystem. It leverages middleware-based tenant resolution (e.g., hostname, subdomains, or custom logic) without requiring model traits or custom database connections.
• Laravel Integration: Designed for deep Laravel integration (e.g., Eloquent, Queues, Cache, Storage, Vite, Filesystem), reducing friction for existing applications.
• Centralized Tenant Management: Supports tenant identification via middleware, route parameters, or custom resolvers, enabling flexible tenant switching.
• Isolation Scope: Automatically isolates database connections, cache, storage, and queues per tenant, ensuring data and resource segregation.

Integration Feasibility

• Zero Code Changes: Claims to require no model trait modifications or Laravel class replacements, though validation is needed for edge cases (e.g., custom query scopes, global scopes).
• Middleware-Based: Tenant resolution happens via middleware (TenantMiddleware), making it easy to integrate into existing Laravel routing.
• Database Agnostic: Supports MySQL, PostgreSQL, SQLite, and MariaDB, with schema management for tenant-specific databases.
• Asset Isolation: Built-in Vite and Filesystem support for tenant-specific assets (e.g., tenant-assets:publish).

Technical Risk

• Performance Overhead: Tenant resolution adds middleware latency. Benchmarking required for high-traffic applications.
• Queue Handling: Queue jobs must be tenant-aware (e.g., QueueTenancyBootstrapper). Serialization of model instances may require adjustments (e.g., using IDs instead of objects).
• Cache Invalidation: Tenant-specific cache tags must be managed carefully to avoid stale data.
• Migration Complexity: Tenant database creation/destruction requires careful handling of migrations and rollbacks.
• Legacy Compatibility: Dropped support for Laravel <9 and PHP <8 may impact older stacks.

Key Questions

1. Tenant Identification Strategy:
   • How will tenants be identified (hostname, subdomain, custom logic)?
   • Will custom tenant resolvers be needed (e.g., API keys, JWT claims)?
2. Database Schema:
   • Will shared tables (e.g., users, roles) be used across tenants, or will all data be tenant-isolated?
   • How will initial tenant database setup be automated (e.g., migrate-fresh --tenant)?
3. Queue and Job Handling:
   • Are jobs tenant-specific, or will a central queue be used with tenant context?
   • How will job retries and failures be managed across tenants?
4. Asset and Storage Isolation:
   • Will tenant-specific storage (e.g., S3 buckets, local paths) be required?
   • How will Vite assets be scoped per tenant?
5. Performance:
   • What is the expected tenant resolution latency under load?
   • Will tenant database connections be connection-pooled or reused?
6. Fallbacks and Errors:
   • How will unrecognized tenants or resolution failures be handled (e.g., 404, redirect to central app)?
   • What’s the strategy for tenant deletion (e.g., cascading drops, data archiving)?

Integration Approach

Stack Fit

• Laravel Versions: Officially supports Laravel 10–13 (PHP 8+). Laravel 9 support dropped in v3.9.0.
• Database Support: MySQL, PostgreSQL, SQLite, and MariaDB via custom schema managers.
• Queue Systems: Supports Laravel Queues (Redis, Database, SQS) with tenant-aware bootstrapping.
• Asset Pipelines: Vite and Laravel Mix integration for tenant-scoped assets.
• Cache Backends: Redis, Memcached, and file-based cache with tenant-specific tags.

Migration Path

1. Pre-Integration:
   • Audit existing code for global scopes, query builders, or middleware that assumes a single database connection.
   • Plan tenant identification strategy (e.g., subdomains like tenant.example.com).
2. Installation:
   • Install via Composer: composer require stancl/tenancy.
   • Publish config: php artisan vendor:publish --provider="Stancl\Tenancy\TenancyServiceProvider".
   • Configure tenancy.php (tenant model, resolvers, database connections).
3. Database Setup:
   • Create a central database for tenant metadata (e.g., tenants table).
   • Use php artisan tenancy:migrate to scaffold tenant databases.
   • Seed initial tenants if needed (--force flag for production).
4. Middleware Integration:
   • Add TenantMiddleware to app/Http/Kernel.php (typically in $middlewareGroups['web']).
   • Configure tenant resolvers (e.g., HostnameTenantResolver).
5. Testing:
   • Test tenant resolution with Tenant::resolve() and Tenant::impersonate().
   • Validate queue jobs, cache, and storage isolation.
6. Deployment:
   • Use php artisan tenancy:setup for initial tenant database creation.
   • Monitor tenant database performance and connection pooling.

Compatibility

• Existing Code: Most Laravel features (Eloquent, Queues, Cache) work out-of-the-box. Customizations may be needed for:
  • Global query scopes (wrap in Tenant::resolve()).
  • Custom Eloquent events (ensure tenant context is set).
  • Third-party packages (check for tenancy support).
• Shared vs. Isolated Data:
  • Shared tables (e.g., users) require careful design (e.g., tenant_id foreign keys).
  • Isolated tables (e.g., posts) are auto-scoped to the tenant’s database.
• Legacy Systems: May require wrappers or adapters for non-Laravel components.

Sequencing

1. Phase 1: Central Tenant Management
   • Implement tenant model, resolvers, and middleware.
   • Set up central database for tenant metadata.
2. Phase 2: Database Isolation
   • Migrate existing data into tenant-specific databases.
   • Test migrate-fresh --tenant for new tenant onboarding.
3. Phase 3: Feature Isolation
   • Isolate queues, cache, and storage per tenant.
   • Validate asset pipelines (Vite, Mix).
4. Phase 4: Rollout
   • Gradually route tenants to isolated databases.
   • Monitor performance and errors.
5. Phase 5: Optimization
   • Tune database connections, cache strategies, and queue workers.
   • Implement tenant-specific monitoring (e.g., New Relic, Datadog).

Operational Impact

Maintenance

• Tenant Lifecycle Management:
  • Creation: Automated via tenancy:migrate or custom commands.
  • Deletion: Use tenancy:drop or cascade drops in migrations.
  • Backup/Restore: Tenant databases must be backed up independently (e.g., mysqldump --databases tenant_db).
• Schema Updates:
  • Run php artisan migrate for central schema changes.
  • Use migrate-fresh --tenant for tenant-specific migrations.
• Configuration:
  • Tenant-specific configs (e.g., .env overrides) can be managed via tenant:config or filesystem paths.
• Logging:
  • Centralized logging (e.g., Laravel Log) with tenant context (e.g., tenant_id in log channels).

Support

• Debugging:
  • Tenant resolution issues can be debugged with Tenant::resolve() logs.
  • Queue job failures require checking QueueTenancyBootstrapper context.
  • Use Tenant::impersonate() for admin debugging across tenants.
• Common Issues:
  • Connection Leaks: Ensure database connections are closed (e.g., DB::disconnect() in middleware).
  • Cache Stale Data: Invalidate tenant-specific cache tags on tenant updates.
  • Queue Context Loss: Verify jobs are dispatched with tenant context (e.g., Tenant::resolve()).
• Documentation:
  • Official docs are comprehensive but may require internal supplements for custom setups.

Scaling

• Database Scaling:
  • Tenant databases can be sharded or moved to separate servers.
  • Read replicas can be configured per tenant.
• Connection Pooling:
  • Laravel’s database connection pooling works per tenant.
  • Monitor connection limits (e.g., max_connections in MySQL).
• Queue Scaling:
  • Tenant-aware queue workers can be scaled horizontally.
  • Use separate queue connections for high-throughput tenants.
• Asset Delivery:
  • Vite and Filesystem isolation may require CDN or edge caching per tenant.

Failure Modes