White Paper Template - Dell United States Official Site | … ITS White... · Web viewUse this MS Word template for writing your ESG/SSG white papers. ... Technical Brief Enterprise

The Role, Function and Use of ITS

(Internet Transaction Server)

in mySAP.com Solutions

Technical BriefEnterprise Systems Group (ESG)

Storage Systems Group (SSG)

Dell White PaperBy Dell SAP CC Walldorf

August 2001

ContentsExecutive Summary..................................................3Introduction.............................................................4

Target Audience...................................................4Introduction.........................................................4

Description of Internet Transaction Server (ITS)....5Overview...............................................................5Description of a request cycle with HTTP/SAPgui protocol transition...............................................6

Planning the System...............................................10Sizing Fundamentals And Recommendations. . .10Calculation of Active Users for One Service......................11Hardware Recommendations.............................12

Conclusions/Recommendations..............................14Contacts.............................................................14

Appendix A: Reference Documents.......................16Appendix B: Glossary of Terms and Acronyms......17Appendix C..............................................................18Vendor Information................................................18

SAP.....................................................................18Dell Computer Corporation...............................18Intel Corporation...............................................19

August 2001 Page 2 Dell ESG Worldwide Marketing

Section 1Executive Summary

When implementing a mySAP.com solution from SAP, the link between the Internet and the SAP system itself is accomplished with SAP’s Internet Transaction Server (ITS). The purpose of this paper is to explain the role, function and use of ITS within the SAP solution and how to leverage Dell’s architecture to construct a resilient ITS environment.

As a pioneer in using Internet technology to create e-commerce success, Dell is well positioned, as a mySAP.com Global Technology Partner, to probe the use of ITS and how it can be best implemented for Dell’s customers’ benefit in an optimized SAP landscape.

Further, proven solutions are the key to any IT strategy. The results contained in this paper are the result of extensive testing done at Dell’s SAP Competence Center and Dell personnel working in SAP’s LinuxLab at SAP headquarters in Walldorf, Germany as well as drawing on the expertise of Dell’s Solution Engineering team at Dell’s worldwide headquarters in Round Rock, Texas, USA. Customer feedback and experience from the field in over 1,500 SAP installations running on Dell™ PowerEdge™ servers and PowerVault™ storage worldwide have also been incorporated into this report.


Section 2Introduction

Target Audience

This paper is targeted toward Dell technical sales representatives, systems consultants and field technical personnel, and customers who have a need to deploy an SAP Internet Transaction Server as part of their SAP solution on Dell PowerEdge server and PowerVault storage systems.

Introduction

SAP customers wanting to harness the power of the Internet, may use SAP Internet Transaction Server (ITS) as the gateway between SAP and the Web. This allows for interactive Web access to the SAP system.

The purpose of this paper is to outline the roles, functions and use of ITS in an SAP environment. This is of particular importance as more SAP customers upgrade their systems’ active users to SAP’s Web-enabled functionality. Dell has already seen a huge increase in demand for PowerApp appliances and PowerEdge servers necessary to build the Internet infrastructure for SAP systems.

Particular attention will be paid to the manner in which a resilient, redundant ITS configuration is created, as the scalability of the ITS product allows for many possible scenarios.


Section 3Description of Internet Transaction Server (ITS)

Overview

HyperText Transfer Protocol (HTTP) is the main protocol used on the World Wide Web for the communication between Web Browsers and Web Servers for the transfer of documents such as HTML (HyperText Markup Language) documents. HTML is an authoring language used to describe a document’s representation on the Internet. HyperText Markup Language documents refer, or connect, to other documents by hyperlinks. These inter-linked documents form the structure of the World Wide Web.

As stated earlier, ITS acts as a gateway between the SAP application server layer and HTML Web technology, thereby allowing interactive Web access to an SAP system. The conventional method of accessing the SAP system interactively is by using an SAP GUI (Graphical User Interface), which is available in different “flavors” such as “SAP GUI for Windows”, “SAP GUI for Java” and “SAP GUI for HMTL”. An SAP GUI displays SAP transaction screens and allows the user to interact directly with the system. It communicates with the SAP System by using a special SAP GUI protocol. Without ITS, a user would need additional middleware to access the SAP System with a Web browser in order to make the connection between SAP technology, such as SAP application servers and SAP GUIs, and Web technology, including Web servers and browsers. This necessary connection is accomplished by ITS and the need for additional middleware is eliminated. ITS dynamically maps the SAP transaction screen elements to HTML and does not do any transaction processing itself. Instead, it hands all business processing over to the SAP system on an application level. The ITS is merely a presentation front end.

ITS consists of two main program components: WGate (Web Gateway) and AGate (Application Gateway), which may exist on the same host or on separate hosts, with or without an intermediate firewall, connected by a TCP/IP network.

Figure 1 provides an overview of the ITS architecture including WGate, AGate and the communication protocols used between them. Figure 1 also details a user request cycle using an HTTP/SAP GUI protocol transition.


Figure 1: SAP Internet Transaction Server Architecture

Description of a request cycle with HTTP/SAPgui protocol transition

The following steps depict a request cycle with an HTTP/SAPgui protocol transition as seen above.

1. A user request is received via Web browser (Internet Explorer, Netscape® Navigator™, etc.).

2. The Web server (e.g. Microsoft® Internet Information Server (IIS), Netscape Enterprise™, Apache) redirects to WGate.

3. WGate sends a prepared request to AGate on the other side of the firewall.

4. A service file is loaded automatically and processed by AGate (interpretation and composition).

5. Transmitted data is received by the Internet application component and executed in the SAP application server (using BAPI methods).

6. Results are transmitted back to the AGate component in ITS.

7. By loading HTML templates and pages and inserting the application results into defined fields, the HTML output page is composed by AGate output processing.

8. The HTML page is sent back to the WGate and the Web server.

9. Data is displayed on the Web browser screen as a true HTML document.

When looking at the ITS server(s) in a real SAP environment, it becomes clear that these servers are the “glue” that holds together the Internet Application mySAP.com. The AGate especially, is not just a data repository. Rather, its built-in functions and responsibilities, which include screen mapping by translation and interpretation, and session and connection management with an underlying SAP application server, make it the most essential part of the Internet


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Transaction Server. Figures 2, 3 and 4 are examples of the SAP ITS look, feel and functionality.

Figure 2: Example of ITS Administration Overview Screen

In general, the ITS is a multi-threading gateway service. Threads are assigned per request/response cycle (not per user session), which results in better performance because threads are re-usable after they have been released of the former user request. In order to provide fast context switching and low latency, ITS has its own memory management, which is very efficient, thus enabling the management of many simultaneous sessions per period.

One of the main functions of the WGate component is to provide the establishment of a “stateful” session with an SAP system via the “stateless” communication channel (“per-request-connection”) of a typical Web server/browser combination. Internal Web server APIs such as Netscape Enterprise Server, Microsoft IIS, and Apache Web Server are supported in addition to the standard CGI (Common Gateway Interface) functions. The WGate portion of ITS resides on the same system as the WEB server.


Figure 3: Example of ITS Administration Process View Screen

With ITS release 4.6D, WGate is capable of communicating with more than one AGate simultaneously via IP link, regardless of where the AGate is physically installed – on the same host or on a different one. It is not necessary to have a dedicated virtual Web server per virtual ITS. Additionally, with release 4.6D compilation 3, ITS is patchable, which means, in order to apply improvements to an ITS installation, it is no longer necessary to uninstall the former ITS and then have the revised server newly installed.


Figure 4: ITS Control Screen


Section 4Planning the System

In order to provide the resilience and redundancy necessary for productive use, at least two Internet Transaction Server instances on different hosts should be used for the implementation of SAP ITS. This recommendation applies to the ITS as well as to the Web server instances associated with WGate.

Figure 5: Example of ITS topology in an SAP configuration

The whole ITS environment is scalable by means of additional server systems with ITS and Web server instances. Depending on the size of the SAP system to be implemented, new ITS instances can be established and connected as needed. Load balancing on the Web side can be provided by a PowerApp.BIG-IP solution (sessions are maintained in the AGate), whereas the AGate must not reside in the WGate/Web server system.


Sizing Fundamentals And Recommendations

Note: The following specifications and numbers are mainly based upon SAP’s experience with on-site installations and benchmark tests using standard SAP business applications.

To get the best sizing results possible, it is necessary to identify the number of concurrent users who will access the SAP system over ITS in each of the different components of the mySAP solution used. The types of users can be distinguished by the kind of load they generate:

Continuous load - e.g. order entry and address changes

Peak load services - e.g. time sheet services and other Employee Self Services (ESS), which are active per user for short periods of time (once a week for instance)

For more information on sizing in a mySAP.com environment, refer to the Dell Technical Brief, Effectively Sizing a mySAP.com Solution. (See http://www.dell.com/downloads/us/pedge/sap_sizing_wp.doc)

For continuous load applications, an average load per time frame can be used, such as number of documents per day, or orders per week. This transactional load can also be broken down into simple, more characteristic dimensions.

For peak load services, the characteristic high load period has to be identified. For instance, the top, or high load period for Time Sheet service may be found early Friday afternoon at one o’clock for four hours. Other services may have a different time point for their peak load.

For all the services, the average time per user transaction has to be estimated or measured. This will be dependant on the number of transaction steps, the duration of each step, and a “think time” of approximately 30 seconds.

For a specific SAP module, the following formula describes the characteristics of the system load:

Active users = (Number of transactions / time frame) * average transaction time.

This calculation has to be done iteratively for each module that will be accessed via Internet Transaction Server. The following example demonstrates how to calculate the number of active users for one service. In this particular example, the service application is a peak load service being used during a high load period.


http://www.dell.com/downloads/us/pedge/sap_sizing_wp.doc

Calculation of Active Users for One Service

Number of active users for the service application Time Sheet (peak load service)

Formula: Active users = (number of transactions / time frame) * average transaction time.

Calculation example:

Number of transactions = 1,000 per week (1,000 employees have to make a time sheet entry every week)

Time frame (High load period) = 4 hours, or 240 minutes, on Fridays from 1 p.m. to 5 p.m. (worst case)

Average transaction time = 15 minutes, based on 30 transaction steps with 30 seconds “think time” per step

Number of active users = (1,000 named users / 240 minutes) * 15 minutes= 63 active users (medium activity) for Time Sheet Application.

Hardware Recommendations

The following table gives a high level overview of server configurations for specific numbers of active users for ITS. When the Internet Transaction Server is divided into separate systems, one for WGate and a second one for AGate, the proposed configurations apply to the server hardware with the AGate component. The WGate resides on the Web server system, whose configuration can be determined by an adequate Web server sizing taking into account an added CPU performance requirements for the WGate service. Table 1 provides a high level overview of server configurations for ITS based on the number of active ITS users. The recommended system configurations assume a dual host ITS landscape for redundancy and resilience, as mentioned earlier.


Table 1: Recommended System Configurations Based on the Number of Active ITS Users

Size Number of Active ITS Users

(Quantity) Platform

A 0 - 250 (2) PowerEdge 2450/2550(1) Intel Pentium III, 866 MHz256 MB RAM(2) HDSK 18 GB, RAID-1 (OS+Swap)

B 251 - 500 (2) PowerEdge 4400(1) Intel Pentium III XEON512 MB RAM(2) HDSK 18 GB, RAID-1 (OS+Swap)

C 501 - 1000 (2) PowerEdge 4400(2) Intel Pentium III XEON1 GB RAM(2) HDSK 18 GB, RAID-1 (OS+Swap)

D 1001 - 3000 (2) PowerEdge 6450(4) Intel Pentium III XEON w/ 1 MB L2 Cache2 GB RAM(2) HDSK 18 GB, RAID-1 (OS+Swap)

E > 3000 (n)* PowerEdge 6450(4) Intel Pentium III XEON with 2 MB L2 Cache2 GB RAM(2) HDSK 18 GB, RAID-1 (OS+Swap)

* The number of PE 6450’s will depend on an exact sizing.


Section 5Conclusions/Recommendations

In this paper, Dell has outlined the vital role, function, and use of the SAP Internet Transaction Server in mySAP.com solutions. Without the careful and planned implementation of the ITS server, no SAP solution today can be effectively Web enabled. It is essential that care be taken in ensuring the setup of a resilient and scalable ITS implementation. The ITS Server is continually being updated by SAP to take advantage of new technologies and make ITS increasingly easier to install and service. Dell PowerEdge servers and PowerVault storage are particularly well suited to provide the ITS functionality required in any sized SAP environment.

Contacts

The information in this document describes results from Dell’s installation and testing with ITS on Dell servers and storage. If needed, Dell has scripts, tools and consulting services/labs available to help companies do their own proof of concept. For questions about this paper or the implementation of SAP Internet Transaction Server with Dell PowerApp, PowerEdge and PowerVault hardware, please contact a Dell sales representative. For comments, questions or feedback about this paper, please send email to [email protected].

Solution Enablement Lab and ShowcaseEnterprise Systems Group/Storage Systems Group

Dell Computer CorporationOne Dell Way

Round Rock, Texas USA 78682+1-(800) WWW-DELL (999-3355)

or +1-(512) [email protected]

www.dell.com

Dell, PowerEdge, PowerApp and PowerVault are trademarks of Dell Computer Corporation. Microsoft and IIS are either registered trademarks or trademarks of Microsoft Corporation. Netscape, Netscape Navigator and Netscape Enterprise are either registered trademarks or trademarks of Netscape Communications Corporation in the U.S. and other countries. Intel, Pentium, Pentium III Xeon, and Itanium are registered trademarks or trademarks of Intel Corporation.

Other trademarks and trade names may be used in this document to refer to either the entities claiming the marks and names or their products. Dell disclaims proprietary interest in the marks and names of others.


http://www.dell.com/

©Copyright 2001 Dell Computer Corporation. All rights reserved. Reproduction in any manner whatsoever without the express written permission of Dell Computer Corporation is strictly forbidden. For more information, contact Dell. Dell cannot be responsible for errors in typography or photography.

Information in this document is subject to change without notice.


Section 7Appendix A: Reference Documents

The following documents are helpful reference materials for deploying ITS:

Dell Technical Brief, “Effectively Sizing a mySAP.com Solution.” See http://www.dell.com/downloads/us/pedge/sap_sizing_wp.doc.

Information on the Internet Transaction Server can be found on the SAP Service Marketplace at www.service.sap.com (a user ID is required and can be obtained immediately). After logging on, go to “Infrastructure and Services”, then “mySAP Technology”, and then under “More Technologies, click on “Internet Transaction Server”. Once a user ID and password has been established, the following URL can also be used for direct access to the ITS Service Marketplace Web page: http://service.sap.com/sap-its.

August 2001 Page 16 Dell ESG/SSG Worldwide Marketing

http://service.sap.com/sap-its

http://www.service.sap.com/

http://www.dell.com/downloads/us/pedge/sap_sizing_wp.doc

Appendix B: Glossary of Terms and Acronyms

B2B – Business-to-Business

B2C – Business-to-Consumer

CRM – Customer Relationship Management

ERP – Enterprise Resource Planning

ESG – Enterprise Systems Group

ISP – Internet Service Provider

ITS – Internet Transaction Server – A portion of any mySAP solution that requires use of the World Wide Web

AGate – Application Gate component of the Internet Transaction Server

WGate – Web Gate component of the Internet Transaction Server


Appendix CVendor Information SAP

Founded in 1972, SAP (NYSE: SAP) is a recognized leader in providing collaborative e-business solutions for all types of industries and for every major market. Headquartered in Walldorf, Germany, SAP is the world's largest inter-enterprise software company, and the world's third-largest independent software supplier overall. SAP software is deployed at more than 30,000 business installations in more than 120 countries and is currently used by companies of all sizes, including more than half of the world's top 500 companies. SAP employs over 23,700 people in more than 50 countries.

SAP has leveraged its extensive experience to deliver the definitive e-business platform for the new Internet economy – mySAP.com™. The mySAP.com collaborative e-business platform allows employees, customers, and business partners to work together successfully – anywhere, anytime. mySAP.com is open and flexible, supporting databases, applications, operating systems, and hardware from almost every major vendor.

SAP is listed on several exchanges including the Frankfurt stock exchange and NYSE under the symbol "SAP."

The technological foundation for SAP collaborative business solutions is the SAP Internet-Business Framework, which supports a company's ability to create an agile business software environment that enables fast responses to new business demands. It provides a comprehensive, scalable platform with which companies can conduct e-business. Strengths in SAP technology that facilitate inter-enterprise collaboration and interoperability include an Internet design; more than 1,500 open interface definitions openly published on the Web; and an open and flexible component-based architecture. Flexible platform support provides for high scalability. SAP offers customers world-class reliability and security as well as the reassurance of accepted industry standards such as the Extensible Markup Language (XML).

Dell Computer Corporation

Dell Computer Corporation (NASDAQ: DELL) is the world's leading direct computer systems company, based on revenues of $32 billion for the past four quarters, and is a premier provider of products and services required for customers to build their Internet infrastructures. The company ranks No. 48 on the Fortune 500, No. 154 on the Fortune Global 500 and No. 10 on the Fortune “most admired” lists of companies. Dell designs, manufactures and customizes products and services to customer requirements, and offers an extensive selection of software and peripherals. Information on Dell and its products can be obtained at www.dell.com.


http://www.dell.com/

Dell Technology Consulting is a group of consulting and implementation services focused on Dell products, related technologies, and valuable assistance for the customer’s I.T. environment. They are dedicated to helping the customer reduce risk, add supplemental resources and become productive more quickly. Customized engagements can help the customer decide which technologies best meet the customer’s needs.

Intel Corporation

Intel, one of the world's largest chip makers, is also a leading manufacturer of computer, networking and communications products. All Dell machines used for the testing described in this paper used Intel processors. Additional information about Intel is available at www.intel.com/pressroom.


http://www.intel.com/pressroom