Microservice architecture consists of multiple independent services that often need to communicate with each other.
This communication can be achieved in two primary ways:
Synchronous communication
Synchronous communication follows a client-server model, where one service sends a request to another and waits for a response before proceeding.
Common protocols
Pros & Cons
Pros:
Cons:
Use cases
Asynchronous communication
Asynchronous communication uses message brokers as an intermediate service for communication between services. Instead of waiting for an immediate response, a service sends a message to a broker, which another service later processes.
Pros & Cons
Pros:
Cons:
Use cases
More...
This communication can be achieved in two primary ways:
- Synchronous
- Asyncronous
Synchronous communication
Synchronous communication follows a client-server model, where one service sends a request to another and waits for a response before proceeding.
Common protocols
- REST APIs – resource-based communication using HTTP methods (GET, POST, PUT, DELETE)
- RPC - Remote Procedure Call. Allows invoking methods on remote services as if they were local. Examples:
- SOAP - XML-based
- gRPC - uses binary format for payloads, high performance,
Pros & Cons
Pros:
- Simple to use and implement
- Immediate data retrieval
Cons:
- Tightly coupled - if one service depends on another that is down, the entire operation fails
- Scalability issues - high traffic can overload serivces
- Latency - slow response times can create bottlenecks
Use cases
- External API calls
- Need immediate response (e.g. authentication)
- Data consistency is critical (e.g. order processing)
Asynchronous communication
Asynchronous communication uses message brokers as an intermediate service for communication between services. Instead of waiting for an immediate response, a service sends a message to a broker, which another service later processes.
Pros & Cons
Pros:
- Loosely coupled - services operate independently, improving scalability
- High availability and resilience - a service can continue operating even if other services are temporarily down
Cons:
- Increased complexity and maintenance - requires additional infrastructure and message handling
- Messages ordering & duplication - messages may arrive out of order or be duplicated, requiring deduplication strategies
Use cases
- Event-driven architecture
- Background processing - immediate response is not required
- High-load systems - where scalability is a priority
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