The Platform Service

• Function as an "Asset Register"
• Track all the platform / system in the orgnization
• Built by the infrastructure team
• Used by:
  • Infra team
  • Tech support team
  • Engineering
  • Accounting

The Command Service

• Function as a repository of command line arguments for given Platforms
• Aid in the automation of support process
• Built by technical support team
• Used by:
  • Tech support team
  • Infra team
  • Engineering

Synchronous Messaging

• Request/Response style
• Request will "wait" for response
• Externally facing services usually synchronous(http requests)
• Services usually need to know about each other
• Here using
  • http
  • grpc

What if mark Http actions as async?

[HttpPost]
public async Task<ActionResult<PlatformService>> CreatePlatform(PlatformCreateDto platformCreateDto) 
{
    var platformModel = _mapper.Map<Platform>(platformCreateDto);
    _repository.CreatePlatform(platformModel);
    _repository.SaveChanges();
}

• From a messaging perspective this method is still synchronous
• The client has to wait for the response
• Async in this context (csharp) means that the action will not wait for a long running operation
• It will hand back it's thread to the thread pool, where it can be reused.
• When the operation finishes it will re-acquire a thread and complete, (and response back to the requester)
• So async here is about thread exhaustion - the requester still has to wait (the call is synchronous

Synchronous Messaging Between Services

• Can and do occur
• It does tend to pair services, (couple them), creating library
• Could lead to long dependency chain

Asynchronous Messaging

• No request / response circle
• Requester doesn't wait
• Event model, publish - subscribe
• Typically used between services
• Event bus is often used