Bird
0
0
LLDsystem_design~12 mins

Emergency handling in LLD - Architecture Diagram

Choose your learning style9 modes available
LearnWhyDeepArchPracticeChallengeDesignRecallScale
System Overview - Emergency handling

This system manages emergency situations by receiving alerts from users or sensors, processing them quickly, and dispatching appropriate responders. It must handle high volumes of requests reliably and ensure timely communication to save lives.

Architecture Diagram
User/Sensor
   |
   v
Load Balancer
   |
   v
API Gateway
   |
   v
Emergency Service
  /    \
 v      v
Cache   Message Queue
  |        |
  v        v
Database  Notification Service
            |
            v
       Responder Devices
Components
User/Sensor
client
Initiates emergency alerts or status updates
Load Balancer
load_balancer
Distributes incoming requests evenly to prevent overload
API Gateway
api_gateway
Routes requests to the emergency service and handles authentication
Emergency Service
service
Processes emergency alerts, checks cache, and triggers notifications
Cache
cache
Stores recent emergency data for quick access
Message Queue
queue
Manages asynchronous notification tasks to responders
Database
database
Stores persistent emergency records and user data
Notification Service
service
Sends alerts to responder devices asynchronously
Responder Devices
client
Receive emergency notifications and respond accordingly
Request Flow - 9 Hops
User/Sensor → Load Balancer
Load Balancer → API Gateway
API Gateway → Emergency Service
Emergency Service → Cache
Emergency Service → Database
Emergency Service → Message Queue
Message Queue → Notification Service
Notification Service → Responder Devices
Emergency Service → Load Balancer
Failure Scenario
Component Fails:Database
Impact:New emergency alerts cannot be stored persistently; historical data access is unavailable
Mitigation:System continues to serve from cache for recent emergencies; alerts are still processed and notifications sent; database replication and failover restore service quickly
Architecture Quiz - 3 Questions
Test your understanding
Which component ensures that incoming emergency alerts are distributed evenly to prevent overload?
ACache
BAPI Gateway
CLoad Balancer
DMessage Queue
Design Principle
This architecture uses caching to speed up repeated emergency data access and a message queue to handle notifications asynchronously, ensuring the system remains responsive and scalable under high load.