#Global Rate Limiting for Services

#Introduction

Global rate limiting protects services from overload in high-concurrency scenarios by:

• Maintaining request volumes within service capacity
• Preventing resource exhaustion through traffic shaping
• Enabling precise access control via conditional policies

Core value: Ensures service stability while maximizing resource utilization

#Features

• Global and conditional policy modes
• Multi-dimension rule matching (Path/Method/Headers)
• Shadow mode for policy validation
• Real-time monitoring dashboard

#Advantages

• ​Precision Control: Granular API-level throttling
• ​Risk Mitigation: Dry-run capability via shadow mode
• ​Flexible Matching: Regex/equality/inequality operators
• ​Visual Validation: Instant policy effectiveness feedback

#Creating Rate Limiting Policies

#Step 1: Access Policy Interface

1. Navigate: ​Service List > ​Target Service
2. Select ​Rate Limiting tab
3. Click ​Create Rate Limiting Policy

#Step 2: Policy Type Selection

Type	Constraints
Global Policy	• Single policy per service OR relationship with conditional policies
Conditional Policy	• Multiple policies allowed AND relationship between rules

#Step 3: Configure Policy Rules

Rule Components

Category	Example	Matching Methods
API PATH	/api/v1	Equal/Not Equal/Regex
HTTP METHOD	POST	Equal/Not Equal
Headers	User-Agent: Mobile	Equal/Not Equal/Regex

Configuration Notes

• Regex matching follows RE2 syntax
• Header matching requires full key:value format
• Multiple rules are AND-combined

#Step 4: Set Rate Threshold

Parameter	Description
Requests/Unit Time	Maximum allowed requests
ShadowMode	• Disabled: Enforces limit Enabled: Audit-only mode

#Rate Limiting Monitoring

#Key Metrics

Metric	ShadowMode Disabled	ShadowMode Enabled
Requests	Actual served	Matched requests
Limited	Rejected requests	Potential rejects

#Data Interpretation

1. Select policy from dropdown
2. Choose time range (last 1h/24h/7d)
3. Compare allowed vs limited curves
4. Validate policy effectiveness

#Policy Management

• ​Global-Conditional Relationship: Requests matching either policy type get limited
• ​Rule Precedence: First-match principle in conditional policies
• ​Policy Editing: Immediate effect after modification