5 Executive details
We choose OGSI Technology Preview [22] as the basis for the development of GSFL prototypes. This is current grid service specification [29] using Apache Tomcat [23] and Apache Axis [24] based on Java-based applications. Tomcat is a servlet container for java servlet [26] and JavaServer Pages [25] technology in office-related applications. AXIS is an application of Simple Object Access Protocol (SOAP) [1] in W3C. In the following section, we give some important parts of GSFL applications.
5.1 Analysis of GSFL
We analyze GSFL Schema with CASTOR [4] and generate Java bindings. CASTOR is a Java open resource data binding architecture that generates Java class and is displayed in XML Schema. It also provides a method to configure the XML document with the corresponding Java object, and vice versa. Use CaStor to automatically generate Java bindings for our XML Schema to avoid writing code. This greatly reduces the time of developing code.
Although CASTOR can map GSFL Schema into Java classes, it is unable to understand the semantics associated with component, such as Castor does not know that there is enough information in GSFL Schema with sufficient information (Namespace and location) to import another GSFL document. It can only use the appropriate acquisition and installation method to map the type of Import to the Java class with the Namespace and Location fields. Therefore, we have to add packages generated by Castor to resolve this issue. But this is much better than you write code.
5.2 Automatically generate WSDL
In addition to using CASTOR, we can also use WSDLAJ [8] to handle personal service WSDL documents. WSDLAJ is a toolkit that can be created, showing, and operating WSDL documents.
As we introduced in Section 4., the GSFL document contains sufficient information about the output activity. Since WSDL can participate in workflow, it is easy to find Types and Messages themselves for input and output information. Other information from WSDLs such as Operations, Ports, etc. can easily get from GSFL itself. The key to automatically generating WSDL for workflow is to provide sufficient information from GSFL Schema.
5.3 GSFL Coordinator (CORDINATOR)
The core of GSFL Workflow is GSFL Coordinator service. This service creates virtual ports and servers that map internal processes to workflows. These ports are virtual because they are not physically in GSFL Coordinator. Despite this, customers can call methods through these ports because they are mapped to a collection of Coordinator.
Figure 5 shows a commonly used control flow. A customer who wants to perform GSFL workflow first begins with a GSFL instance (through standard OGSA Method). The coordinator is then sent to GSFL representing the workflow. On the GSFL document receipt, the coordinator instance dynamically generates a WSDL document, including all new output operations. Then WSDL can be used by customers who can perform workflow and dynamic output operations. When a customer calls an operation of a GSFL Coordinator output, requests to the OGSA WebApp via a servlet container. OGSA WebApp sends GSFLPROVIDER / IntercePter calls using the mapping config.wsdd on the server, which is an extension of the standard OGSA RPCuriprovider class. The OGSA RPCuriprovider class is responsible for assigning the introduced request to the correct service instance based on the requested URL. Since operation is not physically existing on GSFL Coordinator, if this standard provider has been used, the call will fail. However, the custom provider can interrupt this call and sends a universal configuration function in the coordinator. Based on the information provided by the GSFL document, the coordinator handles the request to map the operation to a call set. These calls are actually performed by the service participating in workflow. The provider can distinguish whether the call is active or executed in a static port. One of the static operations of interest is generatewsdl. Including dynamic ports, it automatically generates WSDL (5.2) to the coordinator
6 gsfl example
Considering the following scenarios, in order to achieve a common goal, the grid service needs to communicate with each other. The description of the concept is defined in Section 4, which is stronger than XML in readability. Figure 6 depicts interactions between personal services.
6.1 service provider
The service provider consists of a work queue service, a resource management service, and an execution service set. The work queue service is responsible for the work to be queued for the user; the resource management service is responsible for the various resource pre-store information on the grid and only decisive to the target resource for the implementation; the execution service set is running on each manager Execution of the work and report resource information to the resource management service.
6.2 Activity Model
Activity model consists of a queue operation of a work queue service, an outgoue operation, a getResource operation, and executeJOB operation. Queue operations are responsible for queuing for work requests, work demand information to be provided in a suitable format; out of queue operations work from the queue, depending on the queue rules; the acquisition resource operation in the resource management service uses the queue work information to do specific work The best resources; execution work operations in the implementation of the service are responsible for the implementation of work
6.3 Combined model
The output model in the combination model consists of an output operation Execute. It consists of a model consistent with the control and data model. Operations of these two models include Dequeue, GetResource, and Execute-Job. Therefore, when the customer calls the Execute operation on the workflow instance, the workflow engine gets the next job from the work queue service and then passes the work information to the resource management service via the getResource call. GetResource Calls Returns the target resource to continue working. Using this call on the information and the ExecuteJob operation, it works on the original resource.
In addition, each execution service sends Soft-State resource information to the resource management service by using asynchronous cycle. This is how the resource management service has a method of having every resource information. It is based on this information to determine the best target resources. NOTIFICATION LINKS set consists of Notification Model, which connects the execution service to the resource management service. 6.4 Life Cycle Model
In this example, we require all services to be active at the same time, so we don't need to use all the features provided by the lifecycle model.
Therefore, in order to create more complicated and need to serve more than each personal service, we find that you can work with GSFL to make your personal service (Job Queue Service, Resource Manager Service, and Execution Services).
7 future work
Grid service streaming languages may also have vast space in applications and enhancements. This is also a development work, which will continue to improve according to the needs of the grid. In the future, it will contain the characteristics of processing processing, similar to the XLAN, and the task sorting function in the enhanced workflow, which may be used to cycle and select the structure; automatically integrate the graphical workflow editor.
8 conclusions
We describe the grid service streaming language (GSFL), a workflow architecture based on grid service. We overview existing technologies for processing network service workflows and studies their applications in grid services. Existing network service technology provides some good features that can be utilized, although some needs are not solved, such as peer-to-peer service interactions and use lifecycle management in the service. We have designed GSFL to handle these issues, but also integrate the characteristics of existing network service technology.
references:
[1] Condor: high throughput computing. Http://www.cs.wisc.edu/condor/22.
[2] Dagman (DIRECTED ACYCLIC GRAPH Manager). Http://www.cs.wisc.edu/condor/dagman/, 2002.
[3] assaf arkin. Business process modelling language. Http://www.bpmi.org/Bmpi-Downloads/bpml-spec-
1.0.zip, June 2002.
[4] Assaf Arkin, Sid Askary, Scott Fordin, Wolfgang Jekeli, Kohsuke Kawaguchi, David Orchard, Stefano Pogliani,
Karsten Riemer, Susan Strount, Pal Takacsi-Nagy, Ivana Trickovic, And Sinisa Zimek. Web Services Choreography
Interface. Http://wwws.sun.com/software/xml/developers/wsci/index.html, June 2002. Version 1.0.
[5] R. Armstrong, D. Gannon, A. Geist, K. Keahey, S. Kohn, L. MCInnes, S. Parker, And B. Smolinski. Toward A
Common Component Architecture for High-Performance Parallel Computing. In Proceedings of High Performance
Distributed Computing, Pages 115-124, Redondo Beach, California, 1999. CCA Forum,. [6] T. Berners-Lee, R. Fielding, And L. Masinter. Uniform Resource Identifiers (URI): Generic Syntax.
Http://www.ietf.org/rfc/rfc2396.txt, August 1998.
[7] Don Box, David Ehnebuske, Gopal Kakivaya, Andrew Layman, Noah Mendelsohn, Henrik Frystyk Nielsen,
Satish Thatte, And Dave Winer. Simple Object Access Protocol (SOAP) 1.1. Http://www.w3.org/tr/soap, may
2000.
[8] Roberto chinnici, Martin Gudgin, Jean-Jacques Moreau, And Sanjiva Weerawarana. Web Services Description
Language Version 1.2. Http://www.w3.org/tr/2002/wd-wsdl12-20020709/, July 2002. W3C Working Draft 9.
[9] Erik Christensen, Francisco Curbera, Greg Meredith, And Sanjiva Weerawarana. Web Services Description Language.
http://www.w3.org/tr/wsdl, march 2001. revision 1.1 - March 15, 2002.
[10] Francisco Curbera, Yaron Goland, Yohannes Klein, Frank Leymann, Dieter Roller, And Sanjiva Weerawarana.
Business Process Execution Language for Web Services. Http://www.ibm.com/developerworks/library/ws-bpel/.
Version 1.0 - July 31, 2002.
[11] Distributed Systems Department Pervasive Collaborative Computing Environment Project (PCCE), LBL. PCCE
Quarterly reports. Http://www-itg.lbl.gov/collaboratories/quarterly-reports.html, April 2002.
[12] David C. Fallside. Xml Schema Part 0: Primer. Http://www.w3.org/tr/xmlschema-0/, may 2001.
[13] I. Foster and C. Kesselman, Editors. The Grid: BluePrint for a Future Computing Infrastructure. Morgan
Kaufmann Publishers, July 1998.
[14] Ian Foster, Carl Kesselman, Jeffrey Nick, And Steven Tuecke. The Physiology of The Grid: An Open Grid Services
. Architecture for Distributed Systems Integration http://www.globus.org/research/papers/ogsa.pdf, January 2002. [15] Ian Foster, Carl Kesselman, and Steve Tuecke The Anatomy of the Grid:. Enabling Scalable Virtual Organizations .
International Journal of Supercomputing Applications, 15 (3), 2002.
[16] Dennis Gannon, Rachana Ananthakrishnan, Sriram Krishnan, Madhusudhan Govindaraju, Lavanya
Ramakrishnan, And Aleksander Slominski. Grid Web Services and Application Factories.
http://www.extreme.indiana.edu/xcat/appfactory.pdf, June 2002.
[17] The globus project. Http://www.globus.org/, June 2002.
[18] Steve Graham, Simeon Simeonov, Toufic Boubez, Doug Davis, Glen Daniels, Yuichi Nakamura, And Ryo
NEYAMA. Building Web Services with Java. Sams, 2002.
[19] IBM. The Web Services Description Language for Java Toolkit (WSDL4J). Http: // www-
124.ibm.com/developerWorks/Projects/wsdl4j, July 2002.
[20] Frank Leymann.Web Services Flow Language. Http://www-4.ibm.com/software/solutions/webservices/pdf/wsfl.pdf,
May 2001.
[21] OGSI Technology Preview Release. Http://www.globus.org/ogsa/releases/techpreview/, June 2002.
[22] Apache Jakarta Project. Apache Tomcat. Http://jakarta.apache.org/tomcat/, June 2002.
[23] Apache Xml Project. Apache axis. Http://xml.apache.org/axis/june 2002.
[24] Sun Microsystems Inc. Java Server Pages. Http://java.sun.com/products/jsp, 2002.
[25] Sun Microsystems Inc. Java Servlet Technology. Http://java.sun.com/products/servlet/index.html, 2002.
[26] Satish Thatte. Xlang: Web Services for Business Process Design.
Http://www.gotdotnet.com/team/xml WSSPECS / XLANG-C / Default.htm, 2001.
[27] The Hewlett-Packard Company. Web Services Conversation Language (WSCL) 1.0.
http://www.w3.org/tr/wscl10/, march 2002. [28] Steven Tuecke, Karl Czajkowski, Ian Foster, Jeffrey Frey, Steve Graham, And Carl Kesselman. Grid Service
Specification (Draft 2). Http://www.gridforum.org/ogsi-wg/drafts/gs spec draft02 2002-06-13.pdf, June 2002.
[29] UDDI TECHNICAL White Paper. Http://www-3.ibm.com/services/uddi/pubs/iru uddi technical white paper.pdf,
September 2000. Universal Description, Discovery and Integration Is for Discovering Web Services.
[30] keith Visco and assaf arkin. Castor. Http://castor.exolab.org/, 2002.
[31] World Wide Web Consortium. Http://www.w3.org/, June 2002.
