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Containerization without a microservices approach

The current trends are clear. We should develop software applications using only microservice approach. This sounds goods for new application, where system requirements guides us to go with a microservice approach.
But what happens for the other types of systems. We might need to develop a normal web application, with some backend processing behind it. No crazy NFR, no need to scale to 100.000 RPS or similar stuff.

Monolithic application
As an example let us imagine that, we need to develop a web application that resize our pictures to Instagram size (1x1). There are no special requirements related to availability or scalability and the load on the system is a low. The system is used just by our employees (less than 5.000) for company images that needs to be published on commercial web sites.
Of course, we can imagine a state of the art microservice implementation, with different services that scale by themselves. What if we do not need something like this, but is very appealing for us to deploy the solution in a container using microservice architecture because we want to be able to scale easily and use the benefits that a container offer at CD (Continuous Delivery) level.
The so-called monolithic solution would contain a web application with a dashboard where user can submit their pictures and their email address. Some background process would receive the resize requests and do the hard work. With the new features of .NET we can manage background tasks inside the web application without any issues.

Nothing special, right? If we would go on microservice approach we would have many other services, but we do not want to go on this path. Let’s stay on the monolithic approach and see what we can do.

We can take this two-layer application and deploy as one or to container, as presented below. Things can become too complex and hit scalability issues, but as long the load of the system not increase, nothing stop us to go on this approach.

In the end, if we look closer we have a standard application deployed inside a container and not inside a VM or an App Service. Nothing more than this, but with some additional benefits.

Scaling: When we need to scale-up it is much faster by increasing the number of container instances, than creating a new VM. You do not need to manage the VM creation; the new instance is created automatically using the existing image and can be spin off in a few second.
Combined with a Load Balancer that stays in front of our container instances, things should look very good.
Better integration: No need to different deployments for each environment. The same configuration goes on all environnement.
No custom configuration: Because we use the same image container and we don’t care about the hardware configuration, there are no issues running our system. There is only one image that will run in the same virtualized environment. No specific configuration for deployment in location A or B.
Same environment: Development, testing, integration and production environments are the same. You don’t need to remember to set the flag XXYYZZ with value ‘Magic’ for production environment.
Orchestration: The current management solution that exist for containers are more powerful than the ones that we had until now. You can use out-of-the-box orchestration systems with notification and scaling mechanism that offers a much better availability time without having to configure complex clusters.

Closer to microservices
Yes, we said that we do not need a microservice solution, but we already know that microservices are here to stay. Using an approach like this you already done step 1, hosting your application inside a container. From there, based on your need you can split your application into services inside other containers when requirements will request this.
For example if you realize that, the background process, which make the picture resize consumes too many resources and you want to be able to scale it separately.  You can extract it to a separate container as an independent service.

From development perspective, most of us we would like to work with the latest technologies and architecture patterns. Even so, this is not possible all the time. Nothing stop us to use the power of containerization where we really need it.
Baby step!


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