Service-oriented architecture (SOA) is a software architecture design pattern based on distinct pieces of software providing application functionality as services to other applications.
Key elements of a Service Oriented Architecture are, application fronted, service, service repository and service bus.
Uses open standards to integrate software assets as services, Standardizes interactions of services, Services become building blocks that form business flows, Services can be reused by other applications, thus increased Reusability, Legacy leverage, Agility, Loose coupling
and Interoperation.
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I have a business requirement to transform the business processes which are currently manual and require human interventions to automated using automation platform.
We have chosen Camunda as our BPaaS (Business Process as a Service) platform, for the primary reason of making organisation go towards Event driven + SOA (Service Oriented Architecture).
Challenge I have are related to adopting integration pattern:
Although Workday has enhanced web services to support real time integration, but i have no idea how it can effectively integrate with SAP Concur for bi directional data integration.
I am looking for any reference (in the form of low level design or architecture) which is proven
The closest I got to finding the actual difference is this article.
But I didn't understand what would make me choose one over the other and if microservices can also use a REST API and communicate via http.
I mainly didn't understand what a microservice is and if it can come instead of a webservice, other than the purpose of
breaking large software applications into loosely coupled modules
A microservice is a software architecture, which can be implemented with webservices.
A webservice is just a technology (one of many) for providing services over "web" or HTTP.
The main point is: a web service is (as the name announces) something that you would expect to "deal" with HTTP - in other words it does something in the context of the world wide web.
Whereas a microservice is not subject to the WWW context. At its core a microservice is supposed to provide one specific service - but there is no restriction to the http protocol for example.
Often a microservice implements a restful "web service" - but it doesn't have to be that way!
Beyond that, microservices are often meant as counter model to a huge monolithic application that serves many different kind of requests.
I got simple answer here that says :
Microservices is a new software architecture. It is based on web services. But it can be any service implemented as an independent feature that has its own database and can be deployed independently.
Microservices is an architecture wherein all the components of the system are put into individual components, which can be built, deployed, and scaled individually.
Microservices are the extension of web services.
Web services are typically vertical in nature(Provider-Consumer communication) whereas microservices are horizontal in nature
Microservices are seen as architecture due to the following.
microservices have belonged to one specific application.
microservices are addressing specific concern so that can be said as lightweight.
Changes are isolated in nature because the change in one microservice doesn't affect other (Ex. Changes done in login microservice does not affect the payment microservice)
Scaling individual microservices are easy.
Microservice usually has its own database.
Microservices : -
Microservice is a software architecture that can be used alongside web services. This method involves the splitting of large software applications into decoupled modules where microservices run unique processes and communicate through APIs. Its development can be through the use of either messaging, event-driven APIs, or using non-HTTP backed RPC mechanisms.
Microservices architecture saves the day when large applications fail or are down. If a particular service fails in communication, the overall application cannot be affected by the failure of a single module. The combination of microservices in Java, C#, Python, and mobile software development languages is possible. It can be independently deployed in service models for a business domain.
Web Services :-
A web service is just one of several technologies that can provide services over “web” or HTTP. As a specific type of service-oriented architecture (SOA), web services represent a web application’s functionality.
It defines a mechanisms interaction between an API and the main code by using standard HTTP protocol and universal formats of data representation such as XML, JSON, and so on. This allows software applications developed by different technologies to communicate with each other.
Web services are not involved with frontend development. They are not connected to any development languages or user device software platforms. The combination of different web services into a single one is also possible if written in different languages and for separate operating systems, just like in microservices.
Microservice is a subset of web services. Also used to name Architectures like "Architecture based on microservices"
Microservice is an artifact, not an architecture. Several world class companies know that
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/environments-cfg-alb-shared.html
Before the microservice artifact, we had the classic web service or rest api. Even before this we had the Soap web services with XML.
So, as a summary when someone talk about microservice, he means a subset of web service with some characteristics that differentiate it from classic web services or rest api.
One main characteristic is a unique database or Database per Service
Here another characteristics from the goods like AWS. Some of them apply to rest apis or soap services. I will mark with bold some very specific for microservices.
https://aws.amazon.com/microservices/
Agility
Flexible Scaling
Easy Deployment
Technological Freedom
Reusable Code
Resilience
https://microservices.io/
Highly maintainable and testable
Loosely coupled
Independently deployable
Organized around business capabilities
Owned by a small team
https://www.baeldung.com/cs/microservices-db-design
Database per Service
CQRS
https://learn.microsoft.com/en-us/azure/architecture/microservices/design/data-considerations
Microservice is a piece of autonomous application that performs for a larger application architecture.
Web service is an approach to make the application available to other applications by web ui.
As per Service-Oriented Architecture (SOA) definition, an architectural style that supports service-orientation.
Does that mean only web services (SOAP and REST) are treated as part/backbone of SOA? What about messaging services?
No and yes.
A webservice can be designed in a service orientated way, but a "service" (SOA) describes functionality, a bundle of business logic.
Service orientated architecture means, you have different systems, different users, and the way you implement your business focuses on the whole beeing a service.
The former (SOA) is something abstract, a paradigm, a commitment on how to implement something, the latter is technology (REST, SOAP, ...).
In conjunction with webservices, the "how to" is often described using WS-Business Process Execution Language (short: BPEL). It is used to orchestrate providers and consumers and allows high-traffic processes to scale in the cloud.
Consider your bank, processing many business steps per second in a very standardized fashion; using standard services like transfering money from one account to another.
Talking about Java and JMS, Oracle has a tutorial up: This example shows the steps to create a simple JMS queue in WebLogic Server 11g for testing purposes.
As i know SOA(Service Oriented Architecture) is based on collections of discrete software modules, known as services. These services can exchange information with any other service within the reach of the network without human interaction.
SOA uses SOAP or REST protocol to transfer XML or JSON document between various services.
But i'm confused with ROA(Resource Oriented Architecture) and about what is the difference between the two architectures.
Any help will be appreciated, rectify me if i'm wrong.
As the terms imply a Service Oriented Architecture is oriented at services, and a Resource Oriented Architecture is oriented at resources. In general differences between two things A and B are often best explained by defining the essence of A and B. So it comes down to the question, what is a 'service', and what is a 'resource'?
I'll leave that mostly to the reader, as most developers probably have an idea of what either is. Although it's actually not that easy, as one thing could be seen both as a service, and as a resource (similar to the classic Wave-Particle duality of light in physics). For instance, Flickr is a service that provides you with photo's, but can also be seen as a resource for photos. But basically a resource is more static data (like a photo) and a service is more processing (e.g. delivering a photo, or resizing a photo so they can show a thumbnail of one).
I understand the difference best by looking at the way an application implement its 'functionality':
An application built with a Service Oriented Architecture is more a 'Facade', e.g. it combines or composes its outgoing functionality based on functionality that is in the services it uses 'behind the screens' (possibly over the network). E.g. its core processing consists of calling external services, supplying them with parameters, and combining the results with possibly some extra processing or algorithms for the user.
An application built with a Resource Oriented Architecture does more of its processing internally (e.g. as opposed to calling external components) but uses external resources as input. E.g. its core processing consists of retrieving static resources and then doing more calculating internally.
I'll rectify first:)
For the purpose of this answer let's just say that REST is a way of organizing resources and the operations you perform on them.
SOA uses SOAP or REST protocol to transfer XML or JSON document between various services.
Absolutely not. REST is not a protocol. SOAP is a protocol, that's true. It is frequently used in SOA architectures, particularly for the implementation of SOAP over HTTP or SOAP over JMS. However, SOA does not imply SOAP. You could use any other protocol.
Same applies to XML and JSON. You could use just any other language or dialect.
Now the explanation. SOA is service oriented architecture. Therefore the whole system is made up of services that typically perform some operations. The architecture is based on this. Imagine a cloud of servers where each one holds at least one service, for instance WeatherPredictor, ForexCalculator, etc.
Opposed to this you have the resource oriented architecture, ROA, where the system is made up of resources. Imagine a cloud of servers where each one represents one or more resources, for instance Weather, Euro, Dollar, ...
ROA is typically used in big, open systems, because of the advantages it brings. In ROA architectures you would typically find RESTfull services. RESTfull services are nowadays typically implemented with just JSON over HTTP, or XML over HTTP.
SOA is used a bit everywhere. In SOA you commonly find the SOAP over HTTP, SOAP over JMS, etc.
But some day you may encounter a RESTfull web service that for some weird reason uses SOAP (perhaps the developers needed to embed the message in the SOAP envelope for some obscure reason). I think you won't find this example in real life, but just to show you that SOA or ROA do not imply the protocol to be used, in this case SOAP.
Hope this helps.
Based on my experience, my understanding is as follows:
ROA is API wrappers over data models, SOA is API over functional modules.
ROA is used to provide CRUD operations. SOA is used to link modules at run time.
ROA insulates API consumers from changes to data models. SOA allows drop in replacements of modules, simplifying deployment and customisation.
Two main types of distributed system are:
Request / Response type systems
REST - Resource oriented
Communication with HTTP resource
Involves operation for lifecycle of resource through HTTP GET, PUT, POST etc.
resource data can be cached
SOAP - Service oriented
Involves communication with specific application service
doesn't involve lifecycle operations on service lifecycle management
All messages are sent to service endpoint
endpoint decides how to process request
EJBs - Object oriented
Communication with object
involves marshalling unmarshalling of object
stateful
Message passing type systems - Messaging Queue
You should be able to differentiate the differences between SOA & ROA from here.
ROA (Resource Oriented Architecture) and SOA (Service Oriented Architecture) are two different architectural styles for building distributed systems.
In ROA, the focus is on the resources that are being accessed, and the interactions between clients and servers are centered around those resources. In other words, ROA is a style of architecture that is primarily focused on data or resources, and the way in which those resources can be accessed and manipulated.
In contrast, SOA focuses on services, which are self-contained and modular components that can be reused across different applications. SOA is designed to facilitate the integration of different applications and systems by making it possible to share services between them.
Here are some key differences between ROA and SOA:
Focus: ROA is focused on resources and the interactions between clients and servers that are centered around those resources. SOA, on the other hand, is focused on services and the way in which those services can be shared between different applications.
Granularity: ROA is generally more fine-grained than SOA. The focus on resources means that interactions with the system tend to be more specific and targeted. SOA, on the other hand, is often more coarse-grained, with services that are designed to be reused across many different applications.
Reusability: SOA is designed to maximize the reuse of services across different applications, while ROA is primarily focused on the access and manipulation of resources.
Interoperability: SOA is often used as a way to facilitate the integration of different applications and systems, while ROA is more focused on providing a consistent and reliable way to access and manipulate resources.
Overall, both ROA and SOA are valid architectural styles that can be used to build distributed systems, and the choice between them will depend on the specific requirements of the system being built.
The basic client-server model (even when implemented using questionable interfaces) had a presentation layer, a business layer, and a data layer. Are the directory and discovery methods using webservices models considered a entirely new layer? I would argue that the discovery layer is actually just expanding the role of the data layer to include information on where a service can be found. I am struggling to understand the interplay between webservices and the MVC framework and I am trying to understand the bigger picture as to where the directory and discovery components fit into that framework.
I would say that there is an additional layer -- the service layer -- that sits between your business layer and the presentation layer or your business layer and the data layer depending on whether you're doing a thin- or thick-"client" implementation. This layer would encapsulate service discovery and delivery, including marshaling/unmarshaling data for transfer. See Fowler's Principles of Enterprise Application Architecture Service Layer description. In his concept the service layer sits between the business layer (domain model) and the presentation layer (UI). This concept would apply to a thin-client or web-based client implementation.
I would say there are not basically 3 tiers in the web services model.
Web services is essentially SOA (Service Oriented Architecture), which can imply a multi-tier (n-tier) model. It refers to distributed computing and could be scaled up to a massive system with hundreds of "tiers".
I would agree with you that conceptually, getting your data from a service as compared to a database, could be similar to getting data from other data sourced like databases, etc., and that this could be conceived of as an additional function of the data access layer.
Of course it also depends on semantics. Often "tiers" refers to discreet parts of the overall system (i.e. front-end, middle-tier, back-end data sources, other tiers such as integration with web services, etc.); while "layers" often refers to the vertical layers in the code such as presentation, controller, business logic, data access, etc.