Application server
Encyclopedia
An application server is a software framework
that provides an environment in which applications can run, no matter what the applications are or what they do. It is dedicated to the efficient execution of procedures (programs, routines, scripts) for supporting the construction of applications.
The term was originally used when discussing early client–server systems to differentiate servers that run SQL
services and middleware
servers from file servers.
Later, the term took on the meaning of Web application
s, but has since evolved further into that of a comprehensive service layer. An application server acts as a set of components accessible to the software developer through an API defined by the platform itself. For Web applications, these components are usually performed in the same machine where the Web server is running, and their main job is to support the construction of dynamic pages. However, present-day application servers target much more than just Web page generation: they implement services like clustering, fail-over, and load-balancing
, so developers can focus on implementing the business logic
.
Normally the term refers to Java application servers. When this is the case, the application server behaves like an extended virtual machine for the running applications, transparently handling connections to the database
on one side, and connections to the Web client
on the other.
Other uses of the term may refer to the services that a server makes available or the computer hardware
on which the services run.
and Enterprise JavaBeans. Business logic
resides in Enterprise JavaBeans - a modular server component providing many features, mostly improving application scalability
. The Hibernate
project offers an EJB-3 container
implementation for the JBoss
application server. Tomcat
from Apache
, JOnAS
from ObjectWeb, 974 Application Server from Jimmitry Software Development exemplify typical containers that can store these modules. The EAServer is from Sybase inc.
A Java Server Page (JSP) (a servlet from Java — the Java equivalent of a CGI script
) executes in a Web container
. JSPs provide a way to create HTML
pages by embedding references to the server logic within the page. HTML coders and Java programmers can work side by side by referencing each other's code from within their own.
The application servers mentioned above mainly serve Web application
s. Some application servers target networks other than web-based ones: Session Initiation Protocol
servers, for instance, target telephony networks.
Web Server is a sub set but the Application server is a super set and hence encompasses the past server information that is been stored in database.
operating system and the .NET Framework
technologies in the role of an application server.
applications
.
Zend Server
, built by Zend Technologies
, provides application server functionality for PHP-based applications
Non-Java offerings have no formal interoperability specifications on par with the Java Specification Request
. As a result, interoperability between non-Java products is poor compared to that of Java EE based products. To address these shortcomings, specifications for enterprise application integration
and service-oriented architecture
were designed to connect the many different products. These specifications include Business Application Programming Interface, Web Services Interoperability
, and Java EE Connector Architecture
.
and code
integrity
: By centralizing business logic on an individual server or on a small number of server machines, updates and upgrades to the application for all users can be guaranteed. There is no risk of old versions of the application accessing or manipulating data in an older, incompatible manner.
Centralized configuration: Changes to the application configuration, such as a move of database server, or system settings, can take place centrally.
Security
: A central point through which service-providers can manage access to data and portions of the application itself counts as a security benefit, devolving responsibility for authentication away from the potentially insecure client layer without exposing the database layer.
Performance
: By limiting the network traffic to performance-tier
traffic the client–server model improves the performance of large applications in heavy usage environments.
Total Cost of Ownership
(TCO): In combination, the benefits above may result in cost savings to an organization developing enterprise applications. In practice, however, the technical challenges of writing software that conforms to that paradigm, combined with the need for software distribution to distribute client code, somewhat negate these benefits.
Transaction Support: A transaction
represents a unit of activity in which many updates to resources (on the same or distributed data sources) can be made atomic (as an indivisible unit of work). End-users can benefit from a system-wide standard behaviour, from reduced time to develop, and from reduced costs. As the server does a lot of the tedious code-generation, developers can focus on business logic.
Software framework
In computer programming, a software framework is an abstraction in which software providing generic functionality can be selectively changed by user code, thus providing application specific software...
that provides an environment in which applications can run, no matter what the applications are or what they do. It is dedicated to the efficient execution of procedures (programs, routines, scripts) for supporting the construction of applications.
The term was originally used when discussing early client–server systems to differentiate servers that run SQL
SQL
SQL is a programming language designed for managing data in relational database management systems ....
services and middleware
Middleware
Middleware is computer software that connects software components or people and their applications. The software consists of a set of services that allows multiple processes running on one or more machines to interact...
servers from file servers.
Later, the term took on the meaning of Web application
Web application
A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is coded in a browser-supported language and reliant on a common web browser to render the application executable.Web applications are...
s, but has since evolved further into that of a comprehensive service layer. An application server acts as a set of components accessible to the software developer through an API defined by the platform itself. For Web applications, these components are usually performed in the same machine where the Web server is running, and their main job is to support the construction of dynamic pages. However, present-day application servers target much more than just Web page generation: they implement services like clustering, fail-over, and load-balancing
Load balancing (computing)
Load balancing is a computer networking methodology to distribute workload across multiple computers or a computer cluster, network links, central processing units, disk drives, or other resources, to achieve optimal resource utilization, maximize throughput, minimize response time, and avoid...
, so developers can focus on implementing the business logic
Business logic
Business logic, or domain logic, is a non-technical term generally used to describe the functional algorithms that handle information exchange between a database and a user interface.- Scope of business logic :Business logic:...
.
Normally the term refers to Java application servers. When this is the case, the application server behaves like an extended virtual machine for the running applications, transparently handling connections to the database
Java Persistence API
The Java Persistence API, sometimes referred to as JPA, is a Java programming language framework managing relational data in applications using Java Platform, Standard Edition and Java Platform, Enterprise Edition....
on one side, and connections to the Web client
JavaServer Pages
JavaServer Pages is a Java technology that helps software developers serve dynamically generated web pages based on HTML, XML, or other document types...
on the other.
Other uses of the term may refer to the services that a server makes available or the computer hardware
Computer hardware
Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...
on which the services run.
Java application servers
The Web modules include servlets, JavaServer PagesJavaServer Pages
JavaServer Pages is a Java technology that helps software developers serve dynamically generated web pages based on HTML, XML, or other document types...
and Enterprise JavaBeans. Business logic
Business logic
Business logic, or domain logic, is a non-technical term generally used to describe the functional algorithms that handle information exchange between a database and a user interface.- Scope of business logic :Business logic:...
resides in Enterprise JavaBeans - a modular server component providing many features, mostly improving application scalability
Scalability
In electronics scalability is the ability of a system, network, or process, to handle growing amount of work in a graceful manner or its ability to be enlarged to accommodate that growth...
. The Hibernate
Hibernate (Java)
Hibernate is an object-relational mapping library for the Java language, providing a framework for mapping an object-oriented domain model to a traditional relational database...
project offers an EJB-3 container
Container (data structure)
In computer science, a container is a class, a data structure, or an abstract data type whose instances are collections of other objects. In other words; they are used for storing objects in an organized way following specific access rules...
implementation for the JBoss
JBoss
JBoss Application Server is an open-source Java EE-based application server. An important distinction for this class of software is that it not only implements a server that runs on Java, but it actually implements the Java EE part of Java...
application server. Tomcat
Apache Tomcat
Apache Tomcat is an open source web server and servlet container developed by the Apache Software Foundation...
from Apache
Apache Software Foundation
The Apache Software Foundation is a non-profit corporation to support Apache software projects, including the Apache HTTP Server. The ASF was formed from the Apache Group and incorporated in Delaware, U.S., in June 1999.The Apache Software Foundation is a decentralized community of developers...
, JOnAS
JOnAS
JOnAS is an open-source implementation of the Java EE application server specification, developed and hosted by the ObjectWeb consortium ....
from ObjectWeb, 974 Application Server from Jimmitry Software Development exemplify typical containers that can store these modules. The EAServer is from Sybase inc.
A Java Server Page (JSP) (a servlet from Java — the Java equivalent of a CGI script
Common Gateway Interface
The Common Gateway Interface is a standard method for web servers software to delegate the generation of web pages to executable files...
) executes in a Web container
Web container
Web container is the component of a web server that interacts with the servlets. A web container is responsible for managing the lifecycle of servlets, mapping a URL to a particular servlet and ensuring that the URL requester has the correct access rights...
. JSPs provide a way to create HTML
HTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
pages by embedding references to the server logic within the page. HTML coders and Java programmers can work side by side by referencing each other's code from within their own.
The application servers mentioned above mainly serve Web application
Web application
A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is coded in a browser-supported language and reliant on a common web browser to render the application executable.Web applications are...
s. Some application servers target networks other than web-based ones: Session Initiation Protocol
Session Initiation Protocol
The Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
servers, for instance, target telephony networks.
Web Server is a sub set but the Application server is a super set and hence encompasses the past server information that is been stored in database.
Microsoft
Microsoft positions their middle-tier applications and services infrastructure in the Windows ServerWindows Server
Windows Server is a brand name for a group of server operating systems released by Microsoft Corporation. All are part of Microsoft Servers.- Members :This brand includes the following software:* Windows 2000 Server* Windows Server 2003...
operating system and the .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
technologies in the role of an application server.
Third-party
- MonoMono (software)Mono, pronounced , is a free and open source project led by Xamarin to create an Ecma standard compliant .NET-compatible set of tools including, among others, a C# compiler and a Common Language Runtime....
(not fully .NET compatible), developed by Novell, Inc., licensed under GPL. - Base4 Application Server, an open source project
- TNAPS Application ServerTNAPS Application ServerTNAPS is a freeware .NET cross-platform application server for .NET, Mono, and Java, with component-driven architecture. It is based on the concept of application business logic separation into middleware layer. This is also called three-tier software architecture...
, freeware application server, developed by TN LLC,
PHP application servers
Are used for running and managing PHPPHP
PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...
applications
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
.
Zend Server
Zend Server
Zend Server refers to a PHP application server product line offered by Zend Technologies, released in early 2009 with production support available for Windows and Linux. It is available in two versions, Zend Server and Zend Server Community Edition. Zend Server is supported on x86 and x86-64...
, built by Zend Technologies
Zend Technologies
Zend Technologies Ltd. is an Israeli world wide web infrastructure software company with headquarters in Cupertino, California, U.S., technology center in Ramat Gan, Tel Aviv, Israel and offices in France, Italy and Germany...
, provides application server functionality for PHP-based applications
Other platforms
Open-source application servers also come from other vendors. Examples include:- AppaserverAppaserverAppaserver is an open-source, application server used to create multi-user, database applications. It runs on UNIX-flavored operating systems, connecting Oracle or MySQL to a browser....
- Spring Framework
Non-Java offerings have no formal interoperability specifications on par with the Java Specification Request
Java Community Process
The Java Community Process or JCP, established in 1998, is a formalized process that allows interested parties to get involved in the definition of future versions and features of the Java platform....
. As a result, interoperability between non-Java products is poor compared to that of Java EE based products. To address these shortcomings, specifications for enterprise application integration
Enterprise application integration
Enterprise Application Integration is defined as the use of software and computer systems architectural principles to integrate a set of enterprise computer applications.- Overview :...
and service-oriented architecture
Service-oriented architecture
In software engineering, a Service-Oriented Architecture is a set of principles and methodologies for designing and developing software in the form of interoperable services. These services are well-defined business functionalities that are built as software components that can be reused for...
were designed to connect the many different products. These specifications include Business Application Programming Interface, Web Services Interoperability
Web Services Interoperability
The Web Services Interoperability Organization is an industry consortium chartered to promote interoperability amongst the stack of web services specifications. WS-I does not define standards for web services; rather, it creates guidelines and tests for interoperability...
, and Java EE Connector Architecture
Java EE Connector Architecture
Java EE Connector Architecture is a Java-based technology solution for connecting application servers and enterprise information systems as part of enterprise application integration solutions. While JDBC is specifically used to connect Java EE applications to databases, JCA is a more generic...
.
Advantages of application servers
DataData integrity
Data Integrity in its broadest meaning refers to the trustworthiness of system resources over their entire life cycle. In more analytic terms, it is "the representational faithfulness of information to the true state of the object that the information represents, where representational faithfulness...
and code
Code
A code is a rule for converting a piece of information into another form or representation , not necessarily of the same type....
integrity
Integrity
Integrity is a concept of consistency of actions, values, methods, measures, principles, expectations, and outcomes. In ethics, integrity is regarded as the honesty and truthfulness or accuracy of one's actions...
: By centralizing business logic on an individual server or on a small number of server machines, updates and upgrades to the application for all users can be guaranteed. There is no risk of old versions of the application accessing or manipulating data in an older, incompatible manner.
Centralized configuration: Changes to the application configuration, such as a move of database server, or system settings, can take place centrally.
Security
Computer security
Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...
: A central point through which service-providers can manage access to data and portions of the application itself counts as a security benefit, devolving responsibility for authentication away from the potentially insecure client layer without exposing the database layer.
Performance
Computer performance
Computer performance is characterized by the amount of useful work accomplished by a computer system compared to the time and resources used.Depending on the context, good computer performance may involve one or more of the following:...
: By limiting the network traffic to performance-tier
Multitier architecture
In software engineering, multi-tier architecture is a client–server architecture in which the presentation, the application processing, and the data management are logically separate processes. For example, an application that uses middleware to service data requests between a user and a database...
traffic the client–server model improves the performance of large applications in heavy usage environments.
Total Cost of Ownership
Total cost of ownership
Total cost of ownership is a financial estimate whose purpose is to help consumers and enterprise managers determine direct and indirect costs of a product or system...
(TCO): In combination, the benefits above may result in cost savings to an organization developing enterprise applications. In practice, however, the technical challenges of writing software that conforms to that paradigm, combined with the need for software distribution to distribute client code, somewhat negate these benefits.
Transaction Support: A transaction
Transaction processing
In computer science, transaction processing is information processing that is divided into individual, indivisible operations, called transactions. Each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state...
represents a unit of activity in which many updates to resources (on the same or distributed data sources) can be made atomic (as an indivisible unit of work). End-users can benefit from a system-wide standard behaviour, from reduced time to develop, and from reduced costs. As the server does a lot of the tedious code-generation, developers can focus on business logic.
See also
- Client–server model
- Comparison of application serversComparison of application serversProprietary application servers provide system services in a well-defined but proprietary manner. The application developers develop programs according to the specification of the application server...
— a list of Web application servers listed by programming language. - ServerServer (computing)In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
- Standalone serverStandalone serverA Standalone server is a type of server that is not part of a larger network infrastructure such as an Active Directory domain. In a general sense, a standalone server provides services to clients without relying on any external resources, including authentication...
- Web serverWeb serverWeb server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
- IBM WebSphere Application Server