I have used only Spring framework and deployed as spring boot application It just opens and runs as a java application , Why do a companies with only spring framework runs on app server they can run on JAVA application as usual ? why do they need App server? What all can an app server does ?
Application servers are usually designed to host multiple applications, and manage a set of services that are used by all these applications. These services might include transaction management, timers and task management, HTTP request routing, a message broker (for inter-process communication, among other things), user management, etc. There's usually a graphical or command-line management console, or both.
The Spring framework is usually used to build a single, mostly-self-contained application. Spring does provide common services like transaction management, although they typically require a deal more developer understanding than is the case with, say, a JEE appserver.
There are all sorts of application containers and frameworks, offering different kinds of services in different ways. Often there is no killer reason to pick one over the other, and they are to some extent interchangeable. Spring Boot seems to be rising in popularity right now, because (perhaps) of its better fit to the microservices-type development models that are currently popular.
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I'm familiar with spring boot framework and I developed an Application which helps to handle online Assignments.I used few service classes to handle different tasks of the application and its structure can be seen here.
And I have seen several complex applications built as independent packages based on the task it do in the application.
(1)
My First question is can my Application be called as a MicroServices Application?? Because I have
used independent services for the application development.
(2)
And my second question is Can a application developed in MicroServices Architecture has MVC Architecture at the same time.But I have seen in several tutorials they are 2 different architectures.But a Moicroservices Application also has Models ,Views and Controllers at the same time.
So can those 2 be used at the same time??
Thank you!!
You should do some deeper research yourself about the concept and theory of microservices. Studying other applications without the basic knowledge can be misleading.
(1) Just because you are using multiple classes called services does not mean, you are building microservices application. Microservice application examples can be - student management rest api, question and answer management rest api, UI for administration, UI for public usage etc. All of them can be separate spring boot apps, or any other technology capable of handling the requirements (node.js, python, php, Asp.net ...) You should be able to deploy, test and use them as separate standalone apps.
(2)I think a microservice app does not need views, it can be a rest/soap app, log aggregation app, health check app, messaging service app etc. But different types can use different architecture, one of which can be MVC.
By definition of M. Fowler microservices are
..an approach to developing a single application as a suite of small services, each running in its own process and communicating with lightweight mechanisms, often an HTTP resource API.
As you see the definition is ambiguous. I think you are building a monolith application with a good separation of responsibilities into classes called XyServices - a possible candidates to migrate to microservices.
Microservices according to Chris Richardson
( recognized thought leader in microservices) is Microservices - also known as the microservice architecture - is an architectural style that structures an application as a collection of services that are
Highly maintainable and testable
Loosely coupled
Independently deployable
Organized around business capabilities
Owned by a small team
The microservice architecture enables the rapid, frequent and reliable delivery of large, complex applications. It also enables an organization to evolve its technology stack.
It is way of delivery and based on 12 factors
https://12factor.net/.
We use domain driven design as one of the way.
MVC is way of designing as service where we have model view and controller.
In Microservices architecture we can use MVC in one way where each component will be distributed .
Please go through the Microservice Patterns. It is very good book to understand the Microservices architecture
1.Answer to your question yes your application can be Microservices if it followed the 12 factors as mentioned in the website .
Yes Microservices can be on the pattern of mvc but they will be distributed and like we have Microservices for backend in similar fashion we have micro frontend for UI .
I am building a middle tier which will consume information from multiple downstream systems. The ask is to talk to them over 1 way SSL. I looked up samples but this concept is a bit if a mystery to me. Please help.
The question is too vague IMHO, I'll try to provide general insights
The answer may vary depending on the actual requirements in your organization security department and your actual spring boot configuration.
Spring Boot is a Java framework that usually allows the deployment architecture with an embedded tomcat, jetty or undertow servers that serve Http endpoints exposed by Spring MVC or without an embedded server at all (usually for legacy deployments)
If you in a "legacy" mode (build a WAR) - then HTTPs configuration should be done on the actual server and not in spring boot application.
If you use an embedded server, then the actual technical solution can actually depend on the server you use underneath, at least to some extent.
Indeed like Steffen Ullrich has stated in the comment section, there are many examples of doing this.
For example, take a look at This one
If you want to redirect HTTP requests to HTTPs you should configure your server to do so, and this solution is Tomcat specific.
Another thing to consider is whether you want to use SSL at the level of spring boot at all. Maybe you're running under the gateway / some kind of proxy. In this case, it can make sense to use https for accessing the proxy from outside, but from a proxy to java application you could use HTTP.
I know I'm just speculating about this solution, I've just decided to mention it because in my experience there are many organizations that work like this.
In addition, since spring boot is used for microservice development, the chances are that you have many spring boot artifacts that somehow "talk" to each other, so maybe running HTTPs between them is redundant.
I'm a newbie on Spring Cloud, and I'm a little confused about it. Kubernetes and Spring Cloud are both micro-services framework. If I have Kubernetes(or mesos) already, why do I need use Spring Cloud? I notice that many projects use them both.
What's the difference between Kubernetes and Spring Cloud? They both can provide service discovery, load balance and so on.
I'm really confused.
Kubernetes and Spring Cloud address a lot of the same concerns with Microservices, but with different approaches and technologies. Redhat wrote a great article explaining this. Here the main takeaways:
Spring Cloud has a rich set of well integrated Java libraries to
address all runtime concerns as part of the application stack. As a
result, the Microservices themselves have libraries and runtime agents
to do client side service discovery, load balancing, configuration
update, metrics tracking, etc. Patterns such as singleton clustered
services, batch jobs are managed in the JVM too.
Kubernetes is
polyglot, doesn’t target only the Java platform, and addresses the
distributed computing challenges in a generic for all languages way.
It provides services for configuration management, service discovery,
load balancing, tracing, metrics, singletons, scheduled jobs on the
platform level, outside of the application stack. The application
doesn’t need any library or agents for client side logic and it can be
written in any language.
In some areas both platforms rely on similar
third party tools. For example the ELK and EFK stacks, tracing
libraries, etc.
Some libraries such as Hystrix, Spring Boot are useful
equally well on both environments. There are areas where both
platforms are complementary and can be combined together to create a
more powerful solution (KubeFlix and Spring Cloud Kubernetes are such
examples).
Source: https://developers.redhat.com/blog/2016/12/09/spring-cloud-for-microservices-compared-to-kubernetes/
To understand the differences and similarities in more detail I would recommend to the read the full article.
I'm looking for open source applications that demonstrate the microservices pattern. In particular, I'd like to find one or more applications that can be spun up on real cloud environment up (but with fake data and requests) to demonstrate real-world deployment mechanics.
Unfortunately, I haven't found any good options yet. I'll note that Discourse is a modern 3-tier application, using Rails API, Ember.js, Postgres, and Redis, but it still is much closer to a monolith than an example of microservices. The closest I've found so far is https://github.com/kbastani/spring-cloud-microservice-example but that is more of a framework than an actual application that delivers data.
Not your typical CRUD app but Deis (a PaaS) uses REST APIs mostly to communicate between services. Peatio has a bunch of services that communicate asynchronously through a message queue.
Microsoft provides a demo webshop application based on .NET Core showing how to apply the microservices pattern:
https://github.com/dotnet-architecture/eShopOnContainers
There is also an ebook available: https://aka.ms/microservicesebook
this lagom application example is a microservices application written in Lagom . It is a akka based framework (DDD for design).
Application is complete and working. See if that serve your purpose.
Bit confused with Spring framework and what capabilities application server provides.
I was reading this answer on same site
There he says,
Additionally App Server have components and features to support
Application level services such as Connection Pooling, Object Pooling,
Transaction Support, Messaging services etc.
That means we can optionally use apis of application server to manage transaction in our web application (inject web application :()and I think spring also provides transaction apis. So whats the difference?
Please, help me to make it clear. Thanks you.
When you use app server resources (transactions, connection pools etc.) directly in your application code, you can only run it when it is deployed on an application server or even worse only on that syme type of application server.
Spring allows you to use those resources and configure your application for different environments. The application can be run on any application server or on a simple Tomcat, or on different servers in the cloud.
Spring also allows you to run your code in tests (unit tests) without the need to start up an application server. This is absolutely needed to write automated tests.
Everything that can be done with an application server, can be done with spring as well.
There is a whole world of spring libraries and framework that provide features that are not available directly on application servers.
I can really recomand to give spring a try.....