What does “monolithic” mean?

Question

I\'ve seen it in the context of classes. I suspect it means that the class could use being broken down into logical subunits, but I can\'t find a good definition. Could you give

Answer 1

My definition of a Monolithic design in software development, is a design which requires additional functionality to be added to a single indivisible block of code.

PRO:

• Everything is in one place, and therefore easy to find
• Can be simpler, given there less relations to consider (can also be more complex see cons)

CONS:

• Over time as functionality is added the complexity of the system may exponentially increase, to the point new features are extremely hard or impossible to implement
• Can make it difficult for multiple developers to work with e.g Entity Framework EDMX files have the entire database in a single file which can be extremely difficult for multiple developers to work on.
• Reduced re-usability, by definition it does not have smaller components which can be then reused and re-purposed to solve other problems, unless a complete copy of the code is made and then modified.

Answer 2

If you look up the etymology of the word you'll see it comes from the Greek monos (single) and lithos (stone). In the context of software as you mention it, it describes a single-tiered application in which the code for the user interface and the data access are combined into a single program from a single platform.

Answer 3

It means something is the opposite of modular. A modular application can have parts, referred to as modules, replaced without requiring replacement of the entire application. Whereas a monolithic application, after having a part fixed or upgraded, must be replaced in it's entirety.

From Wikipedia: "Modularity is desirable, in general, as it supports reuse of parts of the application logic and also facilitates maintenance by allowing repair or replacement of parts of the application without requiring wholesale replacement."

So in the context of a monolithic class, all its features are self-contained and if you want to add or alter a feature to the class you would need to alter/add code in the class and recompile it. Conversely a modular class exposes access to functionality which is implemented externally. For example a "Calculator" class may use a separate "Add" class for actually adding numbers; call a "Multiply" function from a separate library; or even call an "Amortize" function from a web service. As long as the each of these functional parts can be altered externally from the class, it is modular.

Answer 4

Interesting question. I don't think there are any formal definitions of what a monolithic class is, but you've got the idea. A class that contains multiple components that are logically unconnected, or pointlessly coupled, is a monolithic class.

If you've read The Pragmatic Programmer, which I strongly recommend, you can define a monolithic class as an anti-pattern that goes against almost everything from that book.

As for examples, you'll find more in the realm of chip and OS design, where there are formal definitions of monolithic chips/kernels, which are similar to a monolithic class. Here are some examples, although each of them can be argued against being on this list:

1. JOGL - Java bindings for OpenGL. This could be arguable, and with good reason.
2. Most academic projects - For obvious reasons.

If you started programming alone, rather than joining a team, then chances are you can open one of your first projects, and there will be a class that is monolithic.

Answer 5

"Monolithic" is a term that has been used to flame succesful software. This link exposes the assumptions inherent in the term, and their limited usefulness.

The basic assumption is that a system works better if it is built from software components that each have an individual, well-defined task. Intuitively, this seems right. If each component works, the entire system must work, right?

In reality, it's not that easy. A larger, compositional (non-monolithic) system can miss a critical function, even when there is no single component to blame. This happens when the architectural design fails to allocate a function to any specific component. This can happen especially if it's a function which doesn't map cleanly to a single component.

Now Linux (to continue with the linked example) in reality is not monolithic. It has a modular userspace on top of a monolithic kernel, a userspace that comes with many separate utilities. Except when it doesn't.

Answer 6

A monolithic architecture is a model of software structure which is created as one piece where all Rails tools (ActionMailer, ActiveJob, ActionCable, etc.) can be gathered together with the code that these tools applies. The tools are not connected with each other but they are also not autonomous.

If one feature needs changes, it will influence the work of the whole process and other features because they are parts of one process.

Let’s recall what Ruby on Rails is, what it can offer, its pros and cons. Its most important benefit is that it is easy to work with.

If you write rails new you immediately get a new application at once, then you can create any REST API you want and use Rails helpers and generators, which makes development even easier.

If you need to send emails in your Rails app, then use Rails ActionMailer. When you need to do some hard processing, ActiveJob will help you. With Rails 5 you will also be able to use websockets out of the box. Thus, it will be easy to create chats or make your application more interactive.

In case you use correct DSL syntax, you can use all that and even more immediately. Moreover, you don’t have to know everything about the internal implementation of these tools, consider it’s DSL, and receive the expected result.