Scaling Considerations for Food Delivery Service
Horizontal Scaling
class AutoScaling:
services = {
'order_service': {'min': 20, 'max': 100, 'target_cpu': 70},
'location_service': {'min': 30, 'max': 150, 'target_cpu': 70},
'matching_service': {'min': 15, 'max': 80, 'target_cpu': 75}
}Database Scaling
-- Sharding by order_id
CREATE TABLE orders_shard_0 PARTITION OF orders
FOR VALUES WITH (MODULUS 16, REMAINDER 0);
-- Time-based partitioning
CREATE TABLE orders_2024_01 PARTITION OF orders
FOR VALUES FROM ('2024-01-01') TO ('2024-02-01');
-- Read replicas
CREATE REPLICA orders_replica_1 FROM orders_primary;Caching Strategy
class CacheHierarchy:
# L1: Local cache (100ms)
# L2: Redis cluster (5ms)
# L3: Database (50ms)
async def get_restaurant_menu(self, restaurant_id):
# Check L1
if menu := self.local_cache.get(f'menu:{restaurant_id}'):
return menu
# Check L2
if menu := await self.redis.get(f'menu:{restaurant_id}'):
self.local_cache.set(f'menu:{restaurant_id}', menu, ttl=300)
return menu
# Query L3
menu = await self.db.get_menu(restaurant_id)
await self.redis.setex(f'menu:{restaurant_id}', 3600, menu)
return menuReal-time Location Scaling
class LocationScaling:
# Use Redis Geo for spatial queries
async def update_location(self, driver_id, lat, lon):
await self.redis.geoadd('drivers', lon, lat, driver_id)
async def find_nearby(self, lat, lon, radius_km):
return await self.redis.georadius('drivers', lon, lat, radius_km, unit='km')Message Queue Scaling
kafka:
topics:
order_events:
partitions: 24
replication: 3
location_updates:
partitions: 48
replication: 3Load Balancing
load_balancer:
algorithm: least_connections
health_check:
path: /health
interval: 10s
sticky_sessions: trueGlobal Distribution
class MultiRegion:
regions = {
'us_east': {'primary': True, 'latency_target': '50ms'},
'us_west': {'primary': False, 'latency_target': '50ms'},
'eu_west': {'primary': False, 'latency_target': '100ms'}
}This scaling document covers key strategies for handling growth. The next document will cover tradeoffs.