Home > Articles > Software Development & Management

Like this article? We recommend

Eliminate Unisys dependencies

There are numerous dependencies on the Unisys OS 2200 operating system that must be systematically identified and eliminated. It is necessary to have a plan for dealing with each type of dependency to assure conformity in the final system and reduce the potential for introducing defects during the porting process.

System Functions

Micro Focus COBOL does not have the same system functions as Unisys COBOL. This requires that Unisys system function calls be converted to Solaris system functions. Each invocation of Unisys system functions must be carefully reviewed to determine the best way of handling them in the new environment. The legacy system uses over 150 different system calls for Unisys Executive subroutines, the DPS, messages, and other functions.

Language Differences

Except for Unisys system functions, the existing Unisys COBOL 85 and MicroFocus COBOL are quite similar. The difference rests largely in file assignments, the handling of binary fields for bit manipulation, and the use of Unisys versus Solaris system subroutines. Automated source code translation ensures that language differences are handled the same way from one program to the next, making maintenance easier. However, the ability to automate such changes depends on the difficulty of the change and the sophistication of the tools being used.

Simple changes, such as changing "SOURCE-COMPUTER. UNIVAC- 1100-60" to "SOURCE-COMPUTER. SUN-SOLARIS" in the CONFIGURATION SECTION of program elements, can be automated easily using either editor macros or simple text-processing scripts.

Simple text replacement is not always viable when the program text to be changed depends on the surrounding context. To successfully automate these changes, the tool must often be aware of both syntactic and semantic elements of the language. Still, most changes that involve identifying a pattern and performing a text replacement can be automated.

In many cases, it is difficult or impossible to find a pattern that can be identified and replaced. This may be simply because there was no standard pattern of usage applied in building the legacy system. These cases can be handled by either manually modifying each problem instance or even writing special case code that "automates" the modification. While this almost always involves more work than simply making the change, it provides the porting team with the ability to evolve the modification process and then re-execute the entire process on the original source base.

Before deciding on an automated or manual approach, it may be useful to assess the extent of the problem, that is, how many times the problem occurs and how many source files are affected. This may help to determine if taking the time to automate the modification is necessary or worthwhile.

Execution Languages

The Unisys system uses the Execution Control Language (ECL) to process a run. These control statements can invoke Executive functions or cause the execution of a program. In the new Sun Solaris environment, control statements are usually written in UNIX scripts using a shell programming language, such as the Korn shell. Programs must be developed to convert Unisys ECL to UNIX shell scripts, or the conversion must be done by hand. In some cases, a database trigger or stored procedures written in Oracle's PL/SQL language may replace the ECL. In other cases, the functionality of the original ECL may no longer be needed. All cases must be analyzed to determine the intended functionality before the optimal migration strategy can be selected.

Some of the existing COBOL programs actually create and run ECL dynamically on the Unisys system. These programs build ECL statements and then call the Unisys Executive subroutine. A total of 293 programs and 24 procs were identified in the legacy system that make calls to this subroutine. During the migration, these generated ECL statements must be replaced with the appropriate UNIX statements and calls to the Unisys Executive subroutine replaced with calls to the UNIX system() call.

Port Existing Functionality to MicroFocus COBOL

The legacy system uses a technique referred to as pseudo processing. Normally, a transaction is processed as soon as the user inputs it into the system by entering it on the screen. Some transactions, however, are not processed right away, but rather are stored in a transaction file and processed at a later time.

The purpose of the pseudo processing is to avoid flooding the system with hundreds of transactions all at once. The Pseudo Reader programs ensure that only one transaction executes at a time by waiting for a transaction to complete or time out before starting the next one.

The question of how to handle pseudo processing in the migration is an interesting one. The existing mechanism appears to be, at best, a crude solution to the problem. It is possible that the new system will have sufficient bandwidth to process all transactions as they arrive. If this is not the case, there are a number of solutions to this problem offered by commercial infrastructure products. For example, Oracle incorporates a Database Resource Manager (DBRM) that can prevent the execution of operations that are estimated to run for a longer time than a predefined limit, as well as provide other mechanisms for guaranteeing performance. One or more of these mechanisms may be used to address the problem. However, it is important to consider the goals of the effort when deciding how to handle this problem. Any solution implemented as part of this pre-componentization effort is likely to be transitional. Therefore, the best solution may be the solution that requires the least effort. If the pseudo-processing capability can be migrated easily as part of the overall system migration, it may be simpler to retain the (obsolete) functionality than to eliminate it.

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