Using Web Services to Load Customer Orders using .Net - json

Question

I would like to create web service(s) that I can publish to external facing network to allow our customers team to send us CRUD operations on customer orders.
What would be the best practice in this case of using Microsoft or Open-Source technologies to serve the customer reqeusts?
Option1:
The web service accepts data XML/JSON
Stores the data locally in a file
A task picks up the file and attempts data load it in the background
Send an email for records that failed
Drawback here is the response from the web service will not be realtime and validation will be limited.
Option2:
The web service accepts data XML/JSON
Attempt data load
Respond immediately if load was success or failure
Drawback here is if the volume of orders increases increases several folds in near future if the infrastructure can handle it.
I am open to using REST with WCF or Web API and any other helpful technologies that can be scaled when demand grows.

Answer 1

Have you tried message queueing?
Basically, in this architecture, there is a client application (called producer) that submits a message to the message broker (message queue), and there is another application (called consumer) that connects to the broker and subscribes for the message to be processed.
The message can be just simple information or a task that will be processed by another application.
The application can act both as producer and consumer.
There are many message queue software, one of them is rabbitmq.
Here is the complete intro about this: https://www.cloudamqp.com/blog/2015-05-18-part1-rabbitmq-for-beginners-what-is-rabbitmq.html
Since the communication is done through the middleman (aka the message queue) it will not provide an immediate response. But you don't need to send the process result (i.e. Order processing in your case) to the email since the application can subscribe for the message of the result.
It is perfect to handle a huge load of processes. As always you can start small (even free) and scale up in the future.
Take a look at the pricing details https://www.cloudamqp.com/ that provides rabbitmq software as a service.

Answer 2

I do this using ActiveMQ as a central message broker (you can also use Azure Service Bus if you have an Azure subscription) and pre-baked domain objects. For your scenario it might look like:
The web service accepts data XML/JSON
yes, you have a REST service that accepts multipart requests, lets say JSON as it's easier to work with on the client side. Before you can send messages it's usually best to convert the incoming client message to a domain message, so all message consumers know the exact format to expect and can therefore validate the message. I usually create these using xsd.exe on Windows using an XSD file that describes the format of the object. xsd.exe turns that XSD into a C# class. It's then just a process of taking the JSON fields and populating an Order class. That Order then gets sent as a message to the broker. At that point you're now in guaranteed messaging land as JMS will take care of that and ActiveMQ will take care of message persistence.
Stores the data locally in a file
rather than a file, you convert the incoming JSON to a domain class, e.g. an Order instance. You'll never see JSON or XML beyond this point as it's all domain classes from here.
A task picks up the file and attempts data load it in the background
yes, the broker has routes defined in a Camel config that tells it to, for example, send messages coming in on the /client topic to the /orders topic. The task is set up as a durable topic subscriber so automatically gets that Order domain object.
Send an email for records that failed
if the Order object contains information about the client (email etc) then the task can send the email on failure but a better pattern is to route the failed Order to the /error topic where a different task, which again is a durable topic subscriber picks it up and logs/sends email/audits etc
if the volume of orders increases increases several folds in near
future
you can cluster the brokers and run multiple Order consumers. If you separate the failure handling into another route, all the order task has to do is process the order and route the message to either the /error or /success topic depending on the outcome. So each route provides a small piece of the puzzle and you can scale up the pieces if the puzzle gets too big.