PO WEEHNAPPLICATION DEVELOPMENT > "AVGUST 7, 1989 a a————ž———-—x-—x-——ma APPLIED INTELLIGENCE SAA Offers Benefit of Cooperative-Processing Support interface, application logic and database major impact on the software technologies of the '90s. There will be dramatic improvements in hardware and software architectures in the 1990s. IBM, Digital Eguipment Corp., ATGT, Hewlett-Packard Co., Soft- ware AG and others are introducing in- tegrated computing architectures that eliminate the current differences among mainframes, midrange machines and PCs. These architectures will let pro- grammers write to a single, common in- terface standard, independent of the tar- get machine. At the strategic level, the most, impor- ant benefit of SAA is support for a co- operative-processing environment. Coop- erative processing implies that different functions of an application reside on dif- ferent machines and the different com- ponents of an application on each ma- chine work together. This is different from distributed pro- cessing, in which similar components of applications reside on different ma- chines. An example of distributed pro- cessing is a distributed database in which the same access function resides blalodu on multiple machines. Each provides a Seus |Aecess similar service with different data. : | The IBM Enterprise Information Sys- tem, which is based on SAA, incorpo- rates a high degree of both cooperative and distributed processing. This article will focus on SAA strategic planning for cooperative processing, A cooperative-processlng approach supports the distribution of both pro- cessing power and data throughout a computer network. In a cooperative-pro- cessing application, each element, of the network is assigned functions that it interface on the workstation and the ap- plication functions split between the two. The fourth has the data access on the host with the user interface and ap- Cooperative Processing ln SAA | How the Three Components ofan Applicatidn Car Be Distributed Among Platforma | Host Computer | Programinable Workstatlon bata Aecebs || Dlalogiie: Fuhetloti Dlalogue bialogiue blalotjue performs best. For example, the func- Cooperative processing implies that different Junctions of td lj rocesso; poga - olaona . zm an application reside on different machines and different com; t rocesso: components plications each machi; ne wor he zej; SE AL, pi and ode -. ot, se ze % (a ; dinating access to large a Eo me plication functions on the workstation. supports workstation ci Spin eneje re specific posti go ppikatjen janj have ice among | for local processing a ai KA gi assigned e firms to announce products host for access to Bec s more Computing nena that implement sedo the cooperative- | — Alon Corp. faksa a Milla aa koncih vironmeni processing configurations illustrated. ' | with its ex on kN rine are poe for Vendors such as Management Science | the host is also a piki ate Ke osna ppleaieca imtil now, it. America Inc, and McCormack 8 Dodge formation for Workstatlon-bnsed cilent tona to deo ruj ja aj Corp. have announced cooperative-pro- .. applications, vaš UE [Pomena Cessing versions of their products that | | — In the most Complex configurutlon, EJ opica bekralci oe g the ad. are primarily host-based, but with the major application functlons nre split be- SKA hoveče vironments such as portion ted to the | tween the workstation and the host, Ma. that take advainto o ena Can be bulit workstation, These vendors market ap- Jor application vendors and inesa or. ei o ar lon plication packages that are resident on . ganizations are moving toward (hla con. Wihenj ua Seno ner. a large host to both preserve the code i figuration as they partitlon npplicatlon three components that pone deve, 884 still provide the benefits of user in. processing Into la, some best ed using a cooperatina prit be separat- terfaces on programmable workstationa, " sulted for the workstatlon, othem more Approach: user "The next logical stage in the imple- ;. | sultable for the host. The first stop in | h mentation of cooperative processing is 8 elient-server configuratlon, in whleh a is č. access. All three might be on a single enem 3 machine (host or arine, or the workstatlon-based iole ie lasi articles on application might be split in any of services—such as database za za IBM Systems three ways, as shown in the figure. from the host. This configurat; o s ap- Application Ar- The first configuration in the figure is propriate for distributed applicat ons cihtecture entirely host-based; the last configura- that reguire a high degree of user Inter- (SAA). The in- tion is entirely workstation-based. In the action and access to remote dala. š troduction of in- second configuration, the application is Information Builders lne., the vendor tegrated compul- | split, with the application function and | of Focus (a tool for user analysis of ing environ- data access on the host, and the user in- data), is moving toward support of' a cil ments such as terface on the workstation. The third ent-server approach that is SAA compll- SAA will have a has the data access on the host, the user ant. Compatible versions of 'ovus nre available for the PS/2 and 8/370 envi- ronmenta, and a verslon for the A8/400 is under development. Focus wlll use a cooperative client-server approricli that, solin Avaklan tlils directlon might be adding process- ing modules to the workstation-based user-lnterface code of a primarily host: based application. In this configuration, much of the dnta editing and validation would be assigned to the workstation. By designing. modular applicatlons with these types of configuratlons in mina, It Is ensler to migrate progressive- ly to a full cooperative-processing envi- ronment. I£ the data-access portlon of an application (s Igolated, it can be ensi- ly modifled to change a single machine appllenilon to une that accesses distrib- uted data wlihin an BAA-cotnpllant en- vlronment, 'Fhw rest o£ the applicatlon does not need to change. Thus, the first steps toward coopera- tive procesalng are to Isolate the user-in- terfnce code for the workstatlon and the database neces« code on the host. These are the components of an application that most, readily adapt to a particular environment. 'Fhe next step is to sepa- rate the appllentlon functions and de- cide which are most approptlate for a workstatlon or host environment. The diseusslon so far has assumed co- operative necesa across the boundary be- tween workstatlon and host. Egually. valid are applieatlons with' components on both large central hosts and smaller departmental hosts, such as an AS/400. Isolation of modules is the key to de- | slening cooperative applications for the Enterprise Information System and SAA. Modules tire used to isolate the various interface portions of the appli- | catlon. 'This applies not only to modular H boundarics defined by the services of | "SAA, but to applicatlon-dependent code | as well. For oxutuple, an enterprise | might. offer Ha own services tor pricing or tnx calculntlons. 'Vhe Interfaces to these services should | also be isolnted frot -the rest, of the ap- | plicatlon. In fact, these moduleg would bo well sulted to n ellent-server configu- ratlon where workstallon-based uppllea. Mona necesa un host based server for cen- tral prielug luformatlon. | (ood applicatlon-development prac- | tices tise Isolatlon technigues to shleld | detnils of dala necess, user luterfuce, ap- plicatlon services, communication ser- | vices und security from other paris of . | the application, These technigues make | it casler to malutaln and port applica- tlon modules regardless of whether SAA | is used. SAA adds to the formula by j Providlng tools und services for Incorpo- ratlug the isolatod modules within a co- describe the advanced, Braphically orlented User-inte 5 Vices provided by SAA.a srka 79 learn more about the these articles, please call The James Martin Report, an information service Ppdalni guarterly, at (800) 842.1240. br dnformatton on seminars, please vse) o fn the United States and Can. adu) Technology Transfer Institute, 1 DO Ši, Santa Monica, Calp | 90402 (213) 394-8305. , tnet Savan St., Carnf« s Lance, LAB SNE ; (ose) 1X United Kingdom subject of 4 734 605. 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