How Microcontainers Gain Against Large Containers

The best practices of modern development, especially when implementing a microservices architecture, involve the use of Docker, Kubernetes, and other container technologies. 

Containers are transforming how enterprises deploy and use applications. The main biggest draws of containers as such are increased efficiency and portability. Сontainers allow running software without worrying about operating systems or dependencies.  So, the container simplifies your software architecture, allowing you to skip building a production environment with the right settings and libraries, as the container already has that built-in. 

What Do You Need to Know About the Containerization of Java Applications?

At first sight, it seems to be very simple - we wrap the application in a container, run it, and it's done. But then you might notice that application performance has decreased, and the cost of cloud infrastructure has increased too. To build your application effectively without expanding the memory it occupies in the cloud; you need to know two important metrics of the containers that have consequences on your future application. These metrics are: 

• Container RAM consumption; 

• Size of container images and how it is linked to the application performance.

Setting up the right architecture for your software application is one of the most critical steps in product development. The subject is not very easy to grasp, especially that the technology of microservices continues to evolve. The most provisional way towards setting the perfect structure for the app includes the latest innovations in the industry, so your app is secure for a few years from now on and does not need replacement. From this angle, one piece of advice for choice and deployment in cloud-based apps is to find the smallest microcontainer available. 

How Do Microcontainers Differ From Large Containers, and Why Do They Perform More Efficiently in the App?

As the popularity of containers grew and software structures moved toward microservices and clouds, there were some disadvantages of large containers that were discovered in the ongoing business environments. 

The software industry made an effort to diminish the deficiencies of large containers by optimization. Historically, when migrating, we take containers corresponding to the OS that was in the original application before containers. Such an approach is correct, as it provides a safe step-by-step migration. This container OS still has all the components that were needed to run on the server and are no longer required. So the next step in this migration would be to move to microcontainers.

A microcontainer is an optimized container modified toward better efficiency. It still contains all the files to provide more scaling, isolation, and parity to the software application. However, it is an improved container, with an optimized number of files kept in the image. Important files left in the microcontainer are shell, package manager, and standard C library.

In parallel, there exists a concept of ‘distroless’ in a field of containers, where all the unused files are fully extracted from the image. It is worth emphasizing the distinction between the concept of microcontainer and distroless. Microcontainer still contains unused files, as they are required for the system to stay completed.  Microcontainer is based on the same system of operation as the regular container and performs all the same functions, with the only difference that its internal files have been enhanced and its size got smaller due to the improvements done by developers. 

Microcontainer contains an optimized number of files, so it still includes all files and dependencies required for application run, but in a lighter and smaller format. For BellSoft Alpaquita, for example, a microcontainer carries all necessary files for launching OpenJDK applications and standard instruments for OpenJDK run. This microcontainer has gone through a magnificent enhancement by the BellSoft team, and its small size provides a higher level of security than Alpine Linux. 

In summary main features of microcontainer are reflected in: 

• Its smaller size;

• Its higher speed for distribution, download, and scaling;

• Security. Microcontainer security is much improved against those containers of larger sizes.  Removing extra files not needed from the image helps to diminish the potential for an external attack.

Microcontainers Choice

There are quite a few basic images existing today among the smallest containers. A good example would be Debian Slim. Debian Slim is one of the most popular Linux distributions and originates from the larger Debian docker. The other well-known microcontainer is Alpine Linux. 

Both these universal base images still contain all the internal components as the large containers do, though they perform better due to the improved sizes of files they carry and some being removed. Universal base images also differ from distroless, as despite the reduced size, they act the same way as large containers. Distroless container images, in turn, usually carry only your application and its runtime dependencies. Distroless images are drastically minimized and considered to be package manager-less, and their practical use and operation differ.  

Returning to the microcontainers, you can make them even smaller and improve their metrics even further. BellSoft did this with Alpine Linux and is releasing this summer a new smaller than Alpine image - Alpaquita Linux. It is lighter and smaller and fully bridged to working with OpenJDK. BellSoft being the author of the integration of the port on musl into OpenJDK, used this muscle advancement further and improved Alpine Linux, creating on its basis Alpaquita Linux. Alpaquita Linux, in addition to the smaller sizes, will gain guaranteed timely updates and fully working standard tools for OpenJDK. 

Microcontainers are the obvious win for your cloud-based application. The ongoing modernization of large-size containers definitely will present to the market new better solutions for universal basic images.