Editing Service-oriented architecture (section)

== Criticism ==
SOA has been conflated with [[Web service]]s;<ref>{{cite web|author=Joe McKendrick|title=Bray: SOA too complex; 'just vendor BS'|url=https://www.zdnet.com/article/bray-soa-too-complex-just-vendor-bs/|publisher=ZDNet}}</ref> however, Web services are only one option to implement the patterns that comprise the SOA style. In the absence of native or binary forms of remote procedure call (RPC), applications could run more slowly and require more processing power, increasing costs. Most implementations do incur these overheads, but SOA can be implemented using technologies (for example, [[Java Business Integration]] (JBI), [[Windows Communication Foundation]] (WCF) and [[data distribution service]] (DDS)) that do not depend on remote procedure calls or translation through XML or JSON. At the same time, emerging open-source XML parsing technologies (such as [[VTD-XML]]) and various XML-compatible binary formats promise to significantly improve SOA performance.<ref>Jimmy Zhang (February 20, 2008) [http://xml.sys-con.com/read/453082.htm "Index XML Documents with VTD-XML"] {{Webarchive|url=https://web.archive.org/web/20080704164141/http://xml.sys-con.com/read/453082.htm |date=July 4, 2008 }}. ''XML Journal''.</ref><ref>Jimmy Zhang (August 5, 2008) [http://soa.sys-con.com/read/250512.htm "i-Technology Viewpoint: The Performance Woe of Binary XML"] {{Webarchive|url=https://web.archive.org/web/20200109144704/http://soa.sys-con.com/read/250512.htm |date=January 9, 2020 }}. ''Microservices Journal''.</ref><ref>Jimmy Zhang (January 9, 2008)  [http://www.devx.com/xml/Article/36379 "Manipulate XML Content the Ximple Way"] {{Webarchive|url=https://web.archive.org/web/20170730063601/http://www.devx.com/xml/Article/36379 |date=July 30, 2017 }}. ''devx.com''.</ref>

Stateful services require both the consumer and the provider to share the same consumer-specific context, which is either included in or referenced by messages exchanged between the provider and the consumer. This constraint has the drawback that it could reduce the overall [[scalability]] of the service provider if the service-provider needs to retain the shared context for each consumer. It also increases the coupling between a service provider and a consumer and makes switching service providers more difficult.<ref>{{cite web | url=http://www.jpmorgenthal.com/morgenthal/?p=31 | title=The Reason SOA Isn't Delivering Sustainable Software | date=June 19, 2009 | publisher=jpmorgenthal.com | access-date=June 27, 2009 }}</ref> Ultimately, some critics feel that SOA services are still too constrained by applications they represent.<ref>{{cite web | url=https://www.zdnet.com/article/soa-services-still-too-constrained-by-applications-they-represent/ | title=SOA services still too constrained by applications they represent | date=June 27, 2009 | publisher=[[ZDNet]] | access-date=June 27, 2009 }}</ref>

A primary challenge faced by service-oriented architecture is managing of metadata. Environments based on SOA include many services which communicate among each other to perform tasks. Due to the fact that the design may involve multiple services working in conjunction, an Application may generate millions of messages. Further services may belong to different organizations or even competing firms creating a huge trust issue. Thus SOA governance comes into the scheme of things.<ref>{{Cite web|url=https://www.opengroup.org/soa/source-book/soa_refarch/governance.htm|title=Governance Layer|website=www.opengroup.org|access-date=2016-09-22|archive-date=June 4, 2016|archive-url=https://web.archive.org/web/20160604042140/http://www.opengroup.org/soa/source-book/soa_refarch/governance.htm|url-status=dead}}</ref>

Another major problem faced by SOA is the lack of a uniform testing framework. There are no tools that provide the required features for testing these services in a service-oriented architecture. The major causes of difficulty are:<ref>{{Cite web|url=http://wso2.com/library/articles/2014/04/how-to-efficiently-test-service-oriented-architecture/|title=How to Efficiently Test Service Oriented Architecture {{!}} WSO2 Inc|website=wso2.com|access-date=2016-09-22}}</ref>
* Heterogeneity and complexity of solution.
* Huge set of testing combinations due to integration of autonomous services.
* Inclusion of services from different and competing vendors.
* [[Platform as a service|Platform]] is continuously changing due to availability of new features and services.