pavi u L aj x 4 | H ' | j |! d [A ] i Pace 68 This is Part 5 of a series of articles on IBM's Systems Application Ar- ciftecture (SAA). The in- troduction of %n- tegrated, comput- ing environ- ments such as SAA will have a hah MARTIN K on the softvare di, reka technologies of the 905. There will be dramatic improvements in hardware and software architectures in the 1990s. IBM, Digital Eguipment Corp., ATST, 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- tant 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 on multiple machines. Each provides a similar service with different, data. The IBM Enterprise Information ŠyS- 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-processing approach Supports the distribution of both pro- cessing power and data throughout a interface, application logic and database access. All three might be on a single machine (host or workstation), or the application might, be split in any of three ways, as shown in the figure. The first configuration in the figure is entirely host-based; the last configura- tion is entirely workstation-based. In the second configuration, the application is split, with the application function and data access on the host, and the user in- terface on the workstation. The third has the data access on the host, the user interface on the workstation and the ap- plication funetions split, between the two. The fourth has the data access on the host with the user interface and ap- Cooperative Processing In SAA | ' Hotw the Three Componetts of an Applicatidh Can Be Distributed Among Platforma Prodraminable Workstatlon | Dlalogue Dlalotjue Dlalogue Dlalogjue Functleh Co PG WEEKNAPPLICATION DEVELOPMENT APPLIED INTELLIGENCE. SAA Offers Benefit of Cooperative-Processing Support Dlalogiie: AVGUST 7, 1989 ere] TT Eo RAI ra ge un this directlon might be adding process- nentation of srative processing is a useen ; ing modules to the workstation-based client-server configuratlon, ln whleh a workstation-based applicatlon reguests user-Interface code of a primarily host: services—such as database access — based npplication. In this configuration, from the host. This configuratlon is ap-'— much of the data editing and rne! propriate for distributed applicautlons would be assigned to the sokobjjee: on. | that reguire a high degree of user |nter- By designing modular app catlons | action and access to reniote dala. with these types of configuratlons in Information Builders lne., (he vendor mind, [4 Is ensler to migrate progressive- | ly to a full cooperative-processing envi- ronment. 1£ the dala-access portlon of an appllcatlon is Isolated, it can be easl: | Iy modified to change a single machine appllentlon to une that accesses distrib- outed duta wlihin an BAA-cotnpilant en- virontnent, 'Fho rest. of the application docs not need to ehange. Thus, the first steps toward coopera- tive processing are to Isolate the user-in- | terfnee code for the workstatlon and the ' dntabase nceesa code on the host. These are the components of an application that most, readily adapt to a particular environment. The next step is to sepa- | rate the appllentlon functions and de- | Host Computer! cide which are most appropriate for a of Focus (a tool for user analysis of data), is moving toward support of a eli: ent-server approach that, Ig SAA compil: ant. Compatible versions of l'ovus nre available for the PS/2 and 8/370 envi- ronments, and a version for tli A8/400 is under development. Focus will tise a cooperative client-server approneh thal, PN m workstatlon or host environment. The discusslon so far has assumed co- operative necess across the boundary be- tween workstatlon and host. Egually valid are applications with components on both large central hosts and smaller departmental hosta, such as an AS/400. A Design Necessity - Isolation of modules is the key to de- | sigyning cooperative applications for the Enterprise Information System and "SAA. Modules tre used to isolate the | various Interface portions of the appli- | catlon. This applies not only to modular | boundarles defined by the services of | SAA, but to applicatlon-dependent code | as well. For exutuple, an enterprise | might. offer s own services for pricing or tnx cnlceulntlong, | The Interfaces to these services should | also be isolated from -the rest of the ap- | plicatlou, In fact, these moduleg would bu well sulted tu m cilent-server configu- rutlon where workstatlon-based upplica- (ona necesa n host based server for cen: tral prlehig Information. Data Fuhetlofi EN Aocebs A Access computer network. In a cooperative-pro- don Avaklan (ovel applicatlon-development prac- cessing application, each element of the ib SS ticeg use Isolntlon teehnigues to shield | network is assigned functions that it OI NU rea mnv detnils of data necess, user Interface, ap- performs best. For example, the func- Cooperative processing implies that different tnctions nf plicatlon services, conimunicatlon ser- | a a x rampi h Junctions of natije Uons assigned to host processors and an application reside on di fY k: vices and security from other parisof . | prog ih mm nej workst i at ons may be zi JJerent machines a nd di fferent th application. These tec hnigues make -Smpieteiy dillerent. Host processors are (0m nenis of a ications ch rhin« 4 Casler to malntaln and a pe ANE an Poceni k po J applications on each machine work together, tion, modiiles reiardlesa ob teti ne a | serving use C00 regardless of whether SAA | dinating access to large corporate a Nema a] is used. SAA adds to the formula by | plication functions on the workstation. providing tools and services for incorpo- A še rating the Isolatod modules within a co- bom | vele ava re Ee, k PERNE MI SNE ŠK srne one soo Sa nnounce ct host lor access to corpornta di nem a Gescribe the advanced, BA Ee a PUnE o enja. that implement each of the cooperative- | Ajon Corp. a Bapucaly orlented user-interface die most business applications. Until now. it endors such as Management Science the host is also a server of Grniralein Mio ue, | has been necessary to assign applica. osne ža ln, and McCormack Ke formation for workstatlon-bnsed cent. — these artic koru about the subject of dons to one environment, forgolng the dorp. l pe k okneoo Cooperative-pro- — expert-system applicationa, Martin tema please call The James vent opgoa of the olher. With the ad- — — mre primarily host bana a a at |. MA the most complex configurutlan, —— ue arta, ed primation service | vent of integrated environmenta such as primarily hostbased, but, with the - major application funetlons nre split be. For informatt« 4 at (800) 2942-1240. | (hat take advantage of both environ. — paprik Jor application vendors and business or. stega, » the United States and Can. ments in a ce operative manner. sanizatlons are moving toward (his con- 741 Ol a Transfer Institute, ge npr et es proraranaje rta. pe o vorov bes ia rni ŽNA ENIM ome | | Ve approach: user The next logical stage in the imple. . ' suitable for the host. The firme oli in trši Zn pi nited Kingdom j | ] ' s a o aaa VE um en mas 6-— vali sm-, me či mije: min Mobi so: