Hello
i'm wondring when i use microservices pattern in laravel & when to use
DDD?
i searched about it without no results
It depends. What kind of domain are you dealing with? How complex should the application be?
From your question, there are three things to consider: 1. Should you use microservice pattern? 2. Should you use DDD? 3. Should you use Laravel?
Microservices are usually used when you have clear organizational structure consisting of large teams. Microservices enable independent deployment, so that a deployment of a service have minimal effect on another. Microservices are usually divided using DDD approach, although you don't have to. Check out this video in which it discusses when to use microservice: https://www.youtube.com/watch?v=GBTdnfD6s5Q&t=1559s
Domain-driven design is an approach which you design a system based on domain knowledge. If you have a small project, and/or you are also the domain expert, you probably don't have to use DDD. However, DDD might be useful to tackle more complex domain which you may not be the domain expert, because it enables smooth communication between your domain experts and your developers. You can also define boundaries of ubiquitous language, which may be useful to divide your microservices.
Laravel is a PHP framework. For your usecase, can PHP fulfill your requirements? PHP is usually great at a more intensive computation task, but slows down noticeably compared to NodeJS. You can find out more about the benchmarks out there. For a framework, Laravel comes with robust features and great code and support, although it comes at a cost of performance. If you want to use microservice, Lumen might be a better choice (it's a lightweight version of Laravel). But then again, if PHP can't fulfill your requirements, you might probably be better off with another language and another frameworks, probably ExpressJS/Spring.
Personally, I have used Laravel in a monolithic-modular fashion, with Onion Architecture for each modules, and design and implement the model of all of them with DDD. It works great so far for my usecase.
Microservice is architecture style but DDD is architecture pattern.
in other words, You can use Microservice for external architecture and DDD or Simple CRUD, or Onion for internal architecture as a service inside your microservice.
You can read more here from Microsoft
In below picture you can figure out this concept better:
Related
I am a completely fresher for Spring Boot. I had learn to perform Basic CRUD operations using REST API. That basic knowledge is enough to working with Spring Boot Project. Can I able to work with that?
No one is technically perfect!
Every day we are exploring new things and implement new solutions as per the new business requirements. The developer should possess a good set of problem-solving skills. That’s because it’s common for developers to come across multiple programming problems while building just about any solution.
If your lead assigned a task to you explore quarkus and implement a simple CRUD operation using go language what you will do?
"I don't know golang", Is this your answer?
Qualities of a good junior software programmer
Learn new things daily which must be useful to the growth of the company, your team and you.
Problem Solving and Logical Thinking
Written and Verbal Communication
Teamwork
Interpersonal skills
Time management
How do I search for answers from StackOverflow like a PRO? This is a very important skill set, Really, I am not joking.
Health - Health(Physical/Mental) is an important asset, don't take official things personally. Manage stress etc...
Coming to technical side
It would be good if you know at least one programming language, in your case java is fine. But if you have the listed skill sets you can learn anything very easily.
Regarding Spring boot
Do you want to become an expert in the Spring framework? Work with one big project, whatever domain.
Refer - https://www.baeldung.com/
Once you become pro - Refer - https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/
As a starter this is fine, but if your application is going to face real customers/users and want to evolve your application over time, then you would need to consider concepts like below
Login/logout security with Spring Security (if stateless then JWT is a good choice)
Evolving code and database with versions of your software (can use Liquibase to evolve and maintain DB changes ).
Handling exceptions as Aspects from Spring.
Having coded business errors so your team can resolve them and classify them accordingly.
I just finished reading Uncle Bob's "Clean Architecture" and now wondering how to apply it in the context of microservices!
On one hand, I think that microservices fall in the "Framework-Drivers" layer since it's an implementation on top of use-cases (they are ways to serve use-cases.) This way, we focus on the core of the app (Entities and Use-cases) and stay flexible in the implementation of the outer layers (including microservices). But since each microservice can be maintained by a different developer/team of developers, they will have a bad time when use-cases change (harder to predict who will be impacted).
On the other hand, we can split our app into multiple microservices, decoupled from each other, and apply Clean Architecture inside each microservice. The pro of this approach is that we can focus on each microservice doing one thing, and doing it well. But the problem is that we started designing using technical separations (microservices) which violates the main Clean Architecture principle of focusing on the business. Also, it will be hard to not duplicate code if two microservices uses the same entity or use-case!
I think the first scenario is the best, but I would like to have feedback from fellow developers on the long-term benefits of both scenarios, and potential troubles.
My two cents:
From Uncle Bob's words, "Micro-services are deployment option, not an architecture". Each micro-service should be deployable, maintainable by different teams (which can be in different geographical locations). Each team can choose their own architecture, programming language, tools, frameworks etc... And forcing each team to use single/same programming language or tool or architecture does not sound good. So each micro-service team must be able to pick their architecture.
How can each team code/maintain/deploy their own micro-service without conflicting with other teams code? This question brings us to how to separate micro-services. IMHO it should be separated on feature based (same principle applies to modularization of mobile application projects where independent teams should be able to work on separate modules/micro-services).
After separating micro-services, the communication between them is implementation detail. It can be done through web-socket/REST API etc... Inside each micro-service, if team decides to follow Clean Architecture, they can have multiple layers based on Clean Arch Principles (Domain/Core - Interface Adapters - Presentation/API & Data & Infrastructure). There can/will be duplicate codes on micro-services, which are OK for micro-services.
As #lww-pai-long said in his answer here splitting based on the Domain responsibilities and DDD is in most cases the best solution.
Still if you worked with a system using micro-services you soon realize that there are other things involved here as well.
DDD Bounded Context as base for micro-services
In most cases splitting your application to micro-services based on Bounded Context is the safe way to go here. From experience I would even say that in some parts of Domain you could go even further and have multiple micro-services per Bounded Context. Example would be if you have quite big part of Domain which represents one Bounded Context. Other example would be if you use CQRS for a particular Domain. Then you can end up having a Write/Domain and Views/Read micro-service.
You can read in this answer how you can split your Domain to micro-services.
It would be advisable as you said to "apply Clean Architecture inside each microservice".
Also, it will be hard to not duplicate code if two microservices uses
the same entity or use-case!
This is something that you have to deal with when working with micro-services in most cases. Duplicating code and/or data across multiple micro-service is common drawback of working with micro-services. You have to take this into account as you on the other hand get isolation and independence of the micro-service and its database. This problem can be partly solved by using shared libraries as some sort of packages. Be careful this is not the best approach for all cases. Here you can read about using common code and libraries across micro-services. Unfortunately not all advice's and principles from Uncle Bob's "Clean Architecture" can be applied when using micro-services.
Non Domain or technical operation micro-services
Usually if your solution is using micro-services you will more or less have micro-services which are not Domain specific but rather some kind of technical task's or non business operations directly. Example could be something like:
micro-service for report generation
micro-service for email generation and forwarding
micro-service for authorization/permission management
micro-service for secret management
micro-service for notification management
These are not services which you will get by splitting your solution based on DDD principles but you still need them as general solution as they could be consumed by multiple other services.
Conclusion
When working with micro-services you will most of the time have a mixture of Domain specific and Domain agnostic micro-services. I think the Clean Architecture could be looked from a little different prospective when working with micro-services.
On one hand, I think that microservices fall in the
"Framework-Drivers" layer since it's an implementation on top of
use-cases (they are ways to serve use-cases.)
It kind of does but it also falls into the other layers like Entities and Use Cases. I think it goes in the direction that if you work on Domain specific services this Diagram becomes the Architecture of each micro-service but not a concept above all micro-services. In the applications where I worked with micro-services each micro-service(the ones which are based on the DDD Bounded Context) had most of this layers if not all of them. The Domain agnostic services are an exception to this as they are not based on Domain Entities but rather on some tasks or operations like 'Create an Email', 'Create a PDF report from html template' or similar'.
I think this question may be better on Sofware Engineering but I'll answer anyway.
My approach would be to use DDD and define each microservice as a Domain Services grouping Use Cases semantically, then link Domain Services with Bounded Context.
Sam newman talk about the importance of separating microservice by domain abraction and not technical one in Building Microservices
The point he makes basically is that defining scaling strategies for microservice based on subdomain will better match the "real live" constraints observed on the production system than using technically based microservice and try to defined a abstract strategy.
And if you look at how something like Kubernetes works it seems to push to that direction. A pod end up being a microservice with multiple containers defined as a complete stack matching a sub-domain if the overhaul application.
It then gets easier in an e-commerce application, for example, to scale the Payment service independently of the Cart service based on customer activity than to scale the web services independently of the job queues in an abstract way.
The way those Bounded Contexts will communicate, i.e request based or event based, depends on the the specific relation between them. To use the same example a Cart may generate an event that will trigger the Payment, while the same Cart may need to request the Inventory before validating the order.
And at the end of a day those Domain Services* and Bounded Contexts can be implemented the same when starting with a monolith, even the Bounded Contexts communication can be. The underlying communication protocol becomes an implementation detail that can easily(kinda) be switch when transitioning to a distributed a.k.a microservices architecture.
I have a question about microservice implementation. right now I am using an api gateway to process all get request to my individual services and using kafka to handle asynchronous post put and delete request. Is this a good way of handling of handling request in a microservice architecture?
Your question is too unspecific to give a good answer. What is a good architecture totally depends on the details of your use cases. Are you serving web pages, streaming media, amass data for analysis, or something completely different? We would also need to know what are you requirements in terms of concurrency, consistency and scalability? What are the constraints for budget/size of development teams, ease of development, dev skills, etc?
For example the decisions you have taken may be considered good if you have strong requirements for a highly scalable input of large data sets and very frequent data collection as well as the team to support it. But it may be considered bad if you have a small team only and are trying to get a quick and cheap MVP for a new service that has limited scalability requirements (because the complexity of the solution slows down your development unnecessarily).
It may be good because the development team is familiar with those technologies and can effectively develop with those. Or it may be bad because your team does not know anything about those and the investment in learning those will not be justifiable by long term gains.
Don't forget that one of the ideas of the microservices architectural style is that each service can be owned by a distinct team that makes its own decisions about what technology to use for implementation (for whatever reason: ease of development, business reasons etc). So in other words the microservices style embraces the old wisdom architecture follows organization.
Here a link to a recommended further read.
To anyone with real world experience breaking a monolith into separate modules and services.
I am asking this question having already read the MonolithFirst blog entry by Martin Fowler. When taking a monolith and breaking it into microservices the "size" element of the equation is the one that I ponder over the most. Specifically, how to approach breaking a monolith application (we're talking 2001: A Space Oddessy; as in it is that old and that large) into micro services without getting overly fine grained or staying too monolithic. The end goal is creating separate modules that can be upgraded indepenently and scaled independently.
What are some recommended best practices based on personal experience of breaking a monolith into microservices?
The rule of thumb is breaking the monolith based on bounded context . The most common way of defining the bounded context is using BU ( Business Unit) . For example the module which does actual payment is mostly a separate BU .
The second thing to consider is the overhead micro-services bring. You should analyse the hardware , monitoring , infra pieces before completely breaking the service. What I have seen is people taking smaller microservices out of monolith instead of going and writing say 10 new service and depreciating the monolith.
My advice will be have an incremental approach . Take the first BU which is being worked upon out of monolith. This will also give a goos learning curve for the whole team.
You should clearly distinguish sub-domain areas (bounded contexts) from you domain.
Usually (if everything is fine with your architecture) you already have some separate components in your monolith application which responsible for each sub-domain. These components interact with each other in one process
(in monolith application) and you should to think about how to put them into separate processes. Of course you need to produce a lot of refactoring when moving one by one parts of the monolith to microservices.
Always remember that every microservice is responsible for some sub-domain.
I strongly recommend you to learn Domain Driven Design.
Domain-Driven Design: Tackling Complexity in the Heart of Software by Eric Evans
Implementing Domain-Driven Design by Vaughn Vernon
Also learn CQRS pattern
At the beginning you also should decide how your micservices will interact with each other.
There are several options:
Direct calls from one service to another
Send messages through some dispatcher service
which abstracts the client service from the knowledge where the called (destination) services are located.
This approach is similar to how proxy server like NGINX works.
Interact through some messaging bus (middleware), like RabbitMQ
You can combine these options, for example Query requests can be processed through Dispatcher Service, Commands and Events through message bus.
From my experience the biggest problem will be to go away from a single database,
which monolith applications is usually used.
In addition some good practices:
Put each microservice in own repository - this isolates from the ability to directly use the code of one micro service in another.
You also get faster checkouts and builds of each microservice on CI.
Interactions with any service should occur only through its public contracts.
It is necessary to aspire that each microservice has its own database
Example of the sub-domains (bounded contexts) for some Tourism Industry application.
Each bounded context can be serviced by a microservice.
We also started our journey some time back and i started writing a blog series for exactly the same thing: https://dzone.com/articles/how-i-started-my-journey-in-micro-services-and-how
Basically what i understood is to break my problem in diff. microservices, i need a design framework which Domain Driven Design gives(Domain Driven Design Distilled Book by Vaugh Vernon).
Then to implement the design (using CQRS and Event Sourcing and ...) i need a framework which provides all the above support.
I found Lagom good for this.(Eventuate , Spring Microservices are some other choices).
Sample Microservices Domain analysis using Domain Driven Design by Microsoft: https://learn.microsoft.com/en-us/azure/architecture/microservices/domain-analysis
One more analysis is: http://cqrs.nu/tutorial/cs/01-design
After reading on Domain Driven Design i think lagom and above links will help you to build a end to end application. If still any doubts , please raise :)
I am trying to coach some guys on building web applications. They understand and use MVC, but I am interested in other common patterns that you use in building web apps.
So, what patterns have you found to fit nicely into a properly MVC app. Perhaps something for Asynchronous processes, scheduled tasks, dealing with email, etc. What do you wish you knew to look for, or avoid?
Not that it matters for this question, but we are using ASP.NET and Rails for most of our applications.
Once you get into MVC, it can be worthwhile to explore patterns beyond the "Gang of Four" book, and get into Martin Fowler's "Patterns of Enterprise Application Architecture."
The Registry pattern can be useful to make well-known objects available throughout the object hierarchy. Essentially a substitute for using global data.
Many MVC frameworks also employ the Front Controller and the Two-Step View patterns.
The "Model" in MVC is best designed as the Domain Model pattern, although some frameworks (led by Rails) conflate the Model with the ActiveRecord pattern. I often advise that the relationship between a Model and ActiveRecord should be HAS-A, instead of IS-A.
Also read about ModelViewController at the Portland Pattern Repository wiki. There is some good discussion about MVC, object-orientation, and other patterns that complement MVC, such as Observer.
This question is so open that it's hard to give a correct answer. I could tell you that Observer pattern is important in MVC (and for webapplication) and it would be a good answer.About all design pattern that exist are common in big web application. You will require to use some Factory to build complexe object and to access some section require some Facade.
If you want more "tips" or good practice instead of design pattern, I would suggest you to use IoC and the use of good Framework instead of starting from scratch. I can suggest you to explain the benefit of having a good ORM engine to drive you persistance layer faster too (usually can come from the Framework too).
Don't look at it from the aspect of what patterns to use with your development approach, but look at it more as how to apply patterns on a problem-by-problem basis. The architectural decisions made for the project provide just as much indication of what patterns to use as other people's experience will dictate.
That said, I have found that I am a fan of the Provider model for having multiple choices to accomplish a single task with ease of deployment added in. Also, the Unit of Work pattern is great for setting transactional boundaries. Largely, though, the architecture and business needs dictate the approach that is taken for any given code change or new development.
As much as I love patterns, I always fear seeing them overused. I have personally seen people that have used them just for the sake of using them, and it has actually made the code harder to maintain and more tightly coupled than it should have been. Also, it is good to know both sides of the patterns argument. A good pattern knowledge should be rounded out with (often considered a pattern, on its own) anti-pattern knowledge, as well.
I would most likely recommend some kind of Dependency Injection as well (Inversion of Control). Probably the single most important supplementary "pattern" to use.