Can somebody provide real world examples of software products or applications (commercial or open source) that have SOA in them?
Like for example some X company claiming that the latest released version of their software product is now SOA compatible.
SOA is not a specification that a software product could be claimed to be SOA compatible. Read more on what SOA is at http://en.wikipedia.org/wiki/Service-oriented_architecture
SOA is basically an architecture/implementation technique which aims towards loose-coupling of the presentation layer with the data layer. Thus, multiple services/modules/applications could access the same data and use it as per their need. This loose-coupling can lead to more of distributed programming. The day you see that a particular service is more in demand, you could add nodes to your cluster for the particular service.
Examples per se would be applications that were build with SOA architecture. Liferay (an open source Java CMS) is a service-based application. All application that expose some sort of an API (see programmableweb.com) can be termed as SOA-enabled where in you pull data and consume it the way you want.
But yes, for sure, SOA is not a specification.
Related
I've seen this question but the answers are simply not good enough. I've searched the web and could find a clear listing of the main differences.
I am particularly surprised to see contradictions in the above link, that holds only 4 short answers.
So the question is, beyond support, what are (all) the differences between Alfresco Community and Enterprise editions (for the current versions of course)?
Are there functional or technical features that available in the Enterprise edition, that are not in the community edition?
I find it strange that it's so difficult to get a clear list. Looking at the forums to find this answer is not a serious option from a business perspective.
Until now, I found this link to be useful, but it's from 2009.
In particular, I find the platform support interesting, with the community edition supporting only lamp stuff:
Linux
MySQL
Tomcat
OpenLDAP
Firefox
And the enterprise edition supporting:
Windows
SQL Server
WebLogic, WebSphere
AD/Kerberos
IE and Safari
Apparently, these features are only available in the enterprise edition:
JMX monitoring
Runtime admininstration: What's that exactly? And what's in the community edition then?
Runtime indexing consistency check and update: What's in the community edition then?
High performance and availability: How is that implemented and what's in the community edition then?
Storage policies
Open source and proprietary technology stack support: which ones exaclty? Which ones are supported in the community edition?
If anyone could guide me towards serious documentation about these differences, that would be great.
I also went through the wiki but could not find an answer to my questions in there.
differences between Enterprise and Community vary in detail from version to version and are mainly visible for administrators. We see or maintain both flavors of Alfresco in midsize to very large environments and I would say it's more or less a question of taste and budget what the best decision / edition is for you. Excellent skills in infrastructure and java are highly advisable for both editions to run Alfresco in production.
The technical differences are not as dramatic as not being able to provide very similar functionality for the users - so if you're actually in a decision you should focus on a good technical partner, the support services and maybe the fact that you only get official patches in the Enterprise subscription, not on the Community. BTW Alfresco Enterprise is not Open Source but this is not a real point of interest for most end users. You can access the code as a subscription customer but it is not public available/accessible.
The main differences in features are already named more or less:
Administration
Enterprise has more views and setting in the admin web GUI. In Community you can access most configuration only from the command line. This may be a restriction but in real live Administrators prefer the command line and scripting automation.
Enterprise lets you change some Alfresco settings during runtime (most settings still require restart). Some can be change in the GUI and more in the jmx interface. Also you're able to stop and start subsystems like the CIFS protocol server. We use this feature to switch a system in read only mode. This point is meant with "runtime admininstration". Community requires restart of the service for most configuration changes. It is possible to work around this by advanced scripting like groovy or by implementing modules.
Indexing
Runtime indexing consistency check and update is not a self healing functionality as expected. You will have to learn (at least for now) that you have to recreate the Alfresco index from time to time even in Enterprise environments and that it is better to focus on good strategies how to speed recreation or how to setup standby indexes instead of hunting failed indexing transactions using the check and update methods. For major document model changes you need to recreate the index anyway.
High performance and availability
This is mainly the cluster and replication functionality which is no longer available in Community. It's similar to MS Clusters: It's a lot, lot work for very view more availability since some concepts are missing. The price is high in terms of complexity and can end up in loss of robustness. Even with enterprise support it's a hard job to keep a alfresco cluster running - so you need very good arguments why to go this way. But of course: its possible and available!
High performance: There shouldn't be any difference and if - I'm very curious about the explanation.
Technology stack
The main difference is the database support. In the Community you only can choose between MySQL and Postgres (No Oracle or MS SQL for Community). All other technologies are independent from Enterprise or Community (AD, Kerberos, OS, Browser, ...)
Java Container: I believe over 95% of all Alfresco installations run in tomcat. That's the configuration which is documented, tested and scales. Using WebLogic or WebSphere gives you no added value except new challenges - quite the contrary: You have to solve most issues for yourself and can't benefit from others experience.
Storage policies: I'm not pretty sure and should check in 4.2.x if the Content Store Selector / Storage policies is no longer available in the Community, but it was there in the 3.x versions.
[Edit]: storage policies have been removed in Community 4.2.x:
NoSuchBeanDefinitionException: No bean named 'storeSelectorContentStoreBase' is defined
If there is a really need for this functionality someone may re-enable that feature by coding a module for Community.
Regards
This page explains the difference between the editions:
https://wiki.alfresco.com/wiki/Enterprise_Edition
This page is the canonical, comprehensive list of the differences.
If you are considering an Enterprise Subscription and you have a question that isn't answered by what you can find on that page, you should talk to your account rep.
Well, regarding JMX monitoring:
Runtime administration: Alfresco enterprise allows to perform certain actions on Alfresco subsystems without restarting the server. This allows you to be very fast during debugging/developing and also making changes in production environment. Also you can access the JMX interface that supports JMX Remoting.
There is no consistency check or update, until you restart the server (during the startup you have to validate/check/rebuild your indexes). There is an option in alfresco.global.properties (or the original repository.properties config file) for that. If you have some inconsistencies in the Alfresco Community index, you're gonna have a bad time xD.
Alfresco Enterprise has specific license for clustering your architecture, the Community edition doesn't support those systems. Replicate and cluster Alfresco is one of the main improvements in performance/scalability/availability you could achieve.
The storage policies allow you to use Content Store selectors in Alfresco Enterprise. You can manage a primary and a secondary file store, and map/connect these stores in your architecture. The Community Edition allows you only to use one content store at a time.
These include everything inside Alfresco (Spring Framework, Apache-Lucene/Solr, Tomcat, and so on), because with the Enterprise license you have also the full support with everything inside the Alfresco package. The difference is that the Community is based on daily builds, supported by community, and therefor not guaranteed. The Enterprise support helps you resolve many problems that you might encounter during developing and in production environment, not only Alfresco related, but also on some configurations on supported platforms (Windows/Linux), your web application servers, and so on.
Hope it helps.
Where can I find a good high-level overview of Enterprise technology concepts and how they intermingle?
Such as, what is a:
Service Bus
Application Server
Messages
Middleware
The book Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions by Hohpe and Woolf, along with its supporting web site http://www.eaipatterns.com/ are terrific resources.
In the same series, Patterns of Enterprise Application Architecture by Martin Fowler is also very valuable. Martin Fowler's website contains a great amount of material, here is a good starting place: http://www.martinfowler.com/articles/enterprisePatterns.html.
SOA Design Patterns by Thomas Erl, and the companion web site, http://www.soapatterns.org/, is even more encyclopedic. I particularly like this treatment of the enterprise service bus pattern and its constituent patterns.
As with all books on patterns, once you've read through the introductory material, they can be used a reference books, allowing you to selectively read the topics that are of interest, and perhaps going back later for a more thorough, cover-to-cover reading.
We've been having a discussion at work over how widely used SOA is. We've been building our businesses processes using SOA for a few months now with varying degrees of success and the question came up about how widely used this architecture is. My manager believes that "most" of the big companies are using SOA and it is gaining steam among the industry, is cutting edge technology and everybody will doing it shortly. I argued that it seemed to be the new buzzword about 2-3 years ago and was never widely adopted.
Does anybody feel strongly one way or another?
Thanks.
SOA is an easy, standard way to write web services that other middleware (and user-space code) can use. If you need to integrate existing code/services with web clients or other middleware clients, its a good thing to consider.
You didn't mention much about what you're trying to accomplish or what technologies you need to integrate, but I have written Oracle SOA web services that are consumed by Android in the mobile sphere, Spring in the web sphere, and other Oracle SOA clients in the enterprise sphere.
All depends on what you're looking to do, but SOA is more of a concept - and a borderline standard for integration architecture, that presupposes any particular implementation.
As a modern large company, is one ERP system better than hundreds of highly specialized applications which are service oriented? To provide a little bit of background, we are providing consulting for a client who wants to invest their resources in a monolithic ERP system which will manage everything! What are the pro's and con's of this approach?
As an application developer, I tend to believe that specialized well written and managed software packages tied together by a service architecture would out perform a monolithic approach.
What do you think?
As an application developer, I tend to
believe that specialized well written
and managed software packages tied
together by a service architecture
would out perform a monolithic
approach.
Maybe, but getting support for one system from one party is easier than getting support from multiple parties and making sure that integration works and keeps on working.
I think a more important question is whether to pick a general ERP or a custom fitted one. Whether the architecture is service oriented or monolithic is maybe is related, but also general ERP systems can be service oriented.
This almost feels like a traditional question on buy vs. build. I will try to lay out
some importan points.
If you clients has deep pockets only then can they viably maintain the high total
cost of ownership and complexity associated with developing and
maintaining custom-designed applications.
Off-the-shelf ERP solutions integrate the best business practices from a variety of
industries and incorporate these best business practices into your
client's operations which ultimately translates into bottom-line improvements.
Custom-designed applications provide the desired degree of functionality,
but their size and complexity require lengthy design, development, and
implementation efforts.
A good example that I can think of is Microsoft. Microsoft spent 10 months and $25 million installing SAP R/3 to replace a
tangle of 33 financial-tracking systems in 26 subsidiaries. As a result of the
implementation, Microsoft estimates annual savings at $18 million,
leading Bill Gates to call SAP "an incredible success story."
Hope this helps you think more broadly from all angles.
Service Oriented Architecture seems to be more and more of a hot quote these days, but after asking around the office I have found that I seem to get many different definitions for it. How would you guys define SOA? What would you consider the official definition?
As Martin Fowler says, it means different things to different people. His article on the topic is pretty good although it isn't quite a definition.
http://martinfowler.com/bliki/ServiceOrientedAmbiguity.html
It may explain, the difficulty coming up with a concrete definition.
Wikipedia: "A SOA is a software architecture that uses loosely coupled software services to support the requirements of business processes and software users. Resources on a network in an SOA enviroment are made available as independent services that can be accessed without knowledge of their underlying platform implementation."
SOA is not that new, but it has potential to achieve some amazing things. But the organization has to be ready for it: the business has to think in processes and that's the big problem
I'd go with:
Defining a series of stateless, client
agnostic business operations created
to be leveraged in multiple
applications.
An SOA design includes components (i.e., services) that can be used by code regardless of implementation (i.e., any OS or langauge). A single instance of a service may also be used by multiple applications, whereas, e.g., a DLL would have to be duplicated for each app and require the same implementation technology as the linking application.
Services in an SOA design are usually implemented as interoperable web services.
There isn't an official definition as Ryan mentioned eariler. However, I find Thomas Erl's view of the whole service-orientation quite well-structured and relevant. Here is the definition of SOA from his SOA Glossary (more):
Service-oriented architecture represents an architectural model that aims to enhance the agility and cost-effectiveness of an enterprise while reducing the overall burden of IT on an organization.
Thomas Erl is the author of many SOA titles most of them receiving endorsement from SOA vendors including IBM, Oracle, and Microsoft. The nice thing about his books is that they are as SOA vendor independent as possible. It means you learn more about service-orientation itself and less about some vendor's middleware that supports SOA.
I agree with all of the people that point you to Fowler on this. Basically it runs like this: service oriented architecture got a reputation as being good, so anything that people want to be associated with good they call SOA. In reality it has a lot of downsides and can create a Service Oriented Gridlock or Dependency Oriented Architecture.
Here's my go at a definition:
Service Oriented Architecture is a systems integration and code reuse approach where applications are dependent on connecting to services provided by other running applications across the network. This is distinct from component architectures, where software components are shared statically between applications in the form of libraries or SDKs, for example.
A clarification here - "Service Oriented Architecture is a systems integration and code reuse approach where applications are dependent on connecting to services provided by other running applications across the network."
I have a scenario where two j2ee applications have been integrated using event driven messaging. Here the above phrases of systems integration and connecting to services provided by other running applications across the network hold good. Can i call this SOA ?
The following principles would hold good here
1) statelessness
2) message oriented - loosely coupled infact de-coupled
3) extensible.
However, the following do not apply
1) platform independence - neither of the applications being integrated has been designed to work in a different platform.
2) The applications are plain j2ee applications which have not been designed with all soa concepts.
I attempted to define SOA in one of my blog posts. Here's an excerpt...
For years it's been standard practice to separate functionality into functions, classes, and modules. The idea has always been that these smaller, highly specialized components are easier to share and maintain than monolithic blocks of code.
Functionally, SOA is not much different. The goals are the same - reusability and easy maintenance. The biggest difference - in the case of a web service SOA - is that the shared library included in your application is replaced with an HTTP call.
Here's a definition for you:
SOA - Software Over Architected. The inclusion of pointless, over-bloated, functional interface framework called an architecture in a pretty web site with a 3d graphic folder flying from one side to the other where "dir /s > a.txt | ftp -s:upload.ftp" did the job.
Software components are not bricks, cannot be generalised by common functional patterns and architecture emerges in the enterprise from good practice, not good design. Software isn't architected, it's engineered.
SCRUM ON!