Home > Articles

  • Print
  • + Share This
This chapter is from the book

9.7 Best Practices for Assembling Test Packages

With regard to breaking down and assembling good test packages, I've already mentioned a number of key approaches I often use. Four of these are worth more discussion, however, and are covered next.

9.7.1 User-Based Test Packages

A simple method of controlling the amount of "noise" or any other functionally derived activities you introduce in a stress-test run is to directly control the number of users tossed into the mix. With this approach, you're not concerned about the load placed on the system per se, you're more concerned with the number of users hosted, and whether each user is executing consistent and repeatable work. I've mentioned elsewhere that I like to create packages of 100 users. One hundred is a nice number simply because it's a round number; its size is significant enough to allow me to build up a test run into a "large stress test" very quickly and in a highly controlled manner.

Load becomes an issue only if a group of 60 or 100 users (or whatever number you choose) overtaxes a system, invalidating the stress-test run. An obvious example might involve executing custom Z reports—if you toss 100 of these into a system configured for only half as many batch processes, you'll simply create a queue of work that monopolizes all batch work processes and completely destroys most DB servers. A better number in this case might be 10 instead. Experiment to find the best number for you.

9.7.2 Functionally Focused Test Packages

Although controlling the pure number of users participating in a stress test makes sense, taking this to the next level and controlling a group of 100 SAP R/3 SD users, for instance, or 10 BW custom InfoCube reporting users, makes even more sense. Of course, you'll need to be careful to ensure that the mix of users (e.g., or batch processes, or reports) adheres to the mix you need to emulate in support of your test's specific success criteria. And your test tool needs to support both the high-water number of users you wish to simulate as well as the ability to create and control multiple packages.

9.7.3 Another Approach—End-to-End Business Processes

Building on the previous approach, this next approach is both intuitive and in many cases simply necessary. That is, because a business process by definition feeds off one transaction (the previous transaction's output data, actually), and then goes through a processing phase only to hand off newly created or processed data to the next transaction in line, the idea of bundling these transactions into a single package seems logical. Beyond this, though, it saves time and effort in scripting, too, because a common set of fewer variables can be leveraged. And a straightforward input-output approach to scripting lends itself to making even cross-component business processes more easily controlled than is otherwise possible. Finally, the granular control made possible through this method makes it easy to quickly ramp up the user count of a stress-test run while simultaneously ramping up the number of complete business processes to be executed.

9.7.4 Tips and Tricks—Making Noise with Noise Scripts

One of my favorite approaches to SAP scripting and stress testing involves the creation and deployment of noise scripts. As I said earlier, noise scripts capture and help represent the background processing or "noise" common in all SAP production systems. I typically create a variety of noise packages, some focused on general functional areas (e.g., MM or FI, where many light-weight transactions are common), whereas others might be focused on SAP Basis activities (to represent the load that monitoring places on a system), specific batch or report jobs, and so on. The key is to create a consistent baseline of user or batch-driven noise behind the scenes, and then quantify the per-package load to establish a tier of potential baselines, as depicted in Figure 9-3. Does this ancillary load represent 10% of the typical production workload? Or 20%? What is the impact of the load on your test hardware (that is, the HW hit)? Consider what many of my colleagues and I deem to be best practices as follows:

  • Baseline just your noise scripts, to ensure they do the job you envisioned for them. Baseline not only SAP application-layer performance, but lower levels as well. Eventually, I recommend that you settle on any number of online users, batch processes, and so on that create an easy-to-measure load on the system, like 10% CPU utilization or disk queue lengths of three per disk partition or drive letter.

  • Keep the target baseline utilization numbers small, so that it's easy to add incremental measurable load to a stress-test run—simply throw another package into the mix, for example, to add another 10% load on the CPU or perhaps another 40 users or three concurrent processes (whatever measurement you judge most valuable).

  • Ensure that your noise scripts are pseudorandom. As I mentioned earlier, they need to be repetitive enough that they maintain a consistent load on the CPU, while random enough to encourage physical disk accesses. In other words, you don't want to create a noise script, or any script for that matter, that executes at different speeds every time it runs, or processes significantly different data between test runs. Make it repeatable!

  • Ensure that you track the number of iterations executed, along with the specific number of discrete noise transactions executed within your noise script or scripts. This is useful after-the-fact, when you're seeking to understand and analyze a stress-test run—I suggest leveraging a counter of sorts within the body of your scripts (e.g., and publishing the counter's value to your output file), or simply dumping the script's output into your output file, to be counted in more of a manual manner after the run.

  • Finally, if sound test management dictates that you should group your noise scripts together, you'll logically want to go to the trouble of creating one or more noise packages that either complement the core load being tested (you may create a noise script that effectively mirrors many of the transactions that represent core activities) or act as a "gap filler" and instead "round out" a test load (e.g., adding batch noise to a primarily online-user–based stress test).

09fig03.gifFigure 9-3 Noise scripts are useful in providing the fundamental underlying nonprimary transaction load underneath all productive SAP systems.

One of the simplest methods of generating noise within a test run is to execute every core T-code twice—not the entire transaction, just the T-code associated with the first transaction in a business process. This kind of incremental and predictable load on the CPU is ideal when it comes time to measure overall performance, because the transaction is always executed from cache the second time it's executed. In this way, it not only does not ever disturb the system's buffer contents but it is easily scripted or added at the last minute in an iterative fashion if you need to bump up the CPU hit on a particular stress-test run.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020