1 Introduction
So far, application development is usually assumed to assume a target environment, which has begun to be assigned, reliable, secure, and centralized management. However, calculating collaboration between systems, data sharing, data sharing, and other new distributed resources. In this way, we care about the connection between enterprises or across the company's systems, whether in smart networks, swap devices, cache services, application servers, storage systems, or storage area network management systems.
This evolutionary pressure produces a new demand for distributed application development and configuration. Today, the development of applications and middleware is for a specific platform, such as Windows NT, UNIX, or class UNIX, mainframe, J2EE, Microsoft .NET, which provides host environments for the application of the application, which is typical. of. These platforms provide different implementation methods, semantic behavior, and APIs, providing management functions from integrated resources to database integration, cluster services, security, workload management, and problem decisions. Regardless of this difference, software, hardware, and human resources will continue to exist, this requires us to achieve the desired resources to achieve dynamic integration of enterprise systems, service provider systems and user systems. Quality, whether using the same safety semantics, distributed workflow, resource management performance, consistent failure processing, problem decision service, or other method. We need a new abstract method or model, new concept, allowing application access and sharing distributed, wide-area network resources and services.
For large-scale, distributed scientific research systems, this problem has been greatly concerned. The work in this group led the development of GRID technology. Grid technology has precisely illustrated this issue and is widely used for science and technology.
In an earlier article, we define GRID technology and its infrastructure as sharing and collaboration of different resources supported, distributed VOS. We define the basic properties of Grid, introduce key protocols and services. Connection protocols care about communication and certification; resource protocols are concerned about consultation, aggregate protocols and services for a single resource, and care for multiple resources. We also describe the Globus Toolkit, a reference implementation of a key GRID protocol for open source. These key agreements support many different major E-chemical research projects.
Now, we discuss and define how Grid's functionality and GRID technology are implemented and applied from three aspects. First, structuring the protocol required for the VO component interaction, we are concerned with the characteristics of the service of the response protocol message. We think Grid is a collection of Grid Service's extension, and Grid Service can be polymeric the needs of VO together in different ways. Grid Service itself can also be defined by the service part of their operation and sharing. We will then define the behavior of the Grid Service app that supports distributed systems. Emphasize functionality (such as "physiology), the Grid's point of view complements the previous protocol (" Analyzing ").
Second, we explain how Grid technology can be combined with Web Services technology. Take the attribute of the desired Web Service, for example, Service's description and discovery, automatically generate the client and server-side code from the service description; service is described to the network protocol; provide an open standard for higher level services, service And tool compatibility; and wide business support. We call this GRID and Web Services technology or expand to "OGSA" - open Grid Service architecture, with the term "architecture", a set of well-defined interfaces, can be used to construct an application system, " Open "means communication scalability, merchant neutrality, standardization process. This architecture uses WSDL, supports the extension of multiple side-by-side interfaces and changes, well received self-description, service discovery, and interoperability protocols. OGSA also has experienced experience from Globus Toolkit. Defining rules and WSDL interfaces for Grid Service, Grid Service is a potential, temporary, stateful service instance, which supports reliable, secure call, life management, notification , Policy management, trust management and virtualization. OGSA also defines the creation of the temporary Grid Service instance and the interface found by the Grid Service instance. This constructs a distributed service system that supports more advanced, creation of distributed services required in modern enterprises and organization computing environments. (Note: We don't have to distribute the object system because the concept of object is too broad). Third, relatively scientific and technical applications, we pay more attention to business applications. We are convinced that the same concepts and mechanisms are applied to two applications, but in commercial applications, we specially require seamless integration, workload, resources, security, network QoS and availability management tools. OGSA's discovery of the Service property is convenient for the higher level of grid service function to map and adapt to local platform facilities. For the same abstraction and mechanism, it can be used in a distributed grid system that supports collaboration with organizational domain and across multiple hierarchical host environments across a single IT domain, and OGSA-oriented service features allow us to be at multiple hierarchies. Resource is virtualized. The same infrastructure means that the source of strategic control of different resources belongs, private and security, better than interactive mechanisms. Therefore, today's enterprise system, from the independent resource island to integrated, multi-storey distributed systems, service formation can be dynamically, flexibly integrated in existing systems and crossover boundary.
The rest of the chapter is arranged in this way, the second part, we look back GRID technology starting point in the commercial sector; Part III, we review Globus Toolkit and Web Services; fourth part, we introduce OGSA; fifth to eighth Some, we will give an example, discuss the implementation of the agreement and the higher service; the ninth part we discussed the relevant work and summarized our discussion in tenth.
We focus on the OGSA and Grid Service Specifications, this as a result of standardization work in GGF and the results of the Globus Toolkit project group and other places. The technical content of this article and some short statements are only the epitome of our working process.
