Quota Service (Port 6380)

The quota-service is a high-performance service responsible for real-time tracking of resource usage and enforcing plan-based limits across the MQUAD platform.

Infrastructure

Port: 6380 (Internal & External)
Primary Cache: Redis (Shared with core services)
Mode: Real-time counter-based enforcement

Core Responsibility

The service tracks consumption for key resources:

Surveys: Total count of surveys per tenant.
Responses: Monthly submission counts.
Storage: Total binary storage used (MB).
Webhooks: Count of active webhook subscriptions.
Team Members: Count of active users per tenant.

Integration Flow

A domain service (e.g., data-service) receives a request (e.g., POST /responses).
The domain service calls GET /check-quota/{tenant_id}/{feature_key} on the quota-service.
The quota-service retrieves the tenant's plan tier from feature-flags-service.
The quota-service checks the current usage counter in Redis.
If under the limit, a success code is returned; otherwise, a 403 Forbidden (Quota Exceeded) is issued.
After the action is completed, the domain service calls POST /increment/{tenant_id}/{feature_key} to update the count.

Redis Counter Keys

Usage counters are stored in Redis using the following pattern:

quota:{tenant_id}:{feature_key}:{period_suffix}

Example: quota:550e8400-e29b-41d4-a716-446655440000:responses:2025-05

Key Endpoints

Method	Path	Purpose
GET	`/check/{tenant_id}/{key}`	Check if tenant has remaining quota
POST	`/increment/{tenant_id}/{key}`	Increment usage for a specific feature
POST	`/decrement/{tenant_id}/{key}`	Decrement usage (e.g., on survey deletion)
GET	`/usage/{tenant_id}`	Get summary of all usage for a tenant
POST	`/reset/{tenant_id}`	Manual reset of tenant quotas (e.g., on plan upgrade)

Configuration

Standard plan limits are managed via the feature-flags-service, but the quota-service handles the atomic increment/decrement logic to ensure consistency across distributed microservice instances.