Architecting Real-World Enterprise Application

Agenda CPR - Background Challenges in the Architecture Architecture Details Q & A Summary

Background CPR – Computerized Patient Record Manages all the medical information of soldiers First version introduced at 2001  Based on RDS, VB6, Oracle Current version is 5.1.3

Background The medical info is organized in “Meetings” Implements the full medical cycle of IDF units doctors Supports various processes

Background A rewrite to.NET is required  Support for VB6 is over  Improving performance A good chance to improve current processes

Challenges Network – The network is very tight, from 64Kb. – The network has “hiccups”. Performance – Current application is very slow. Flexibility – Changes can take long time to be executed. – Deployment of a new version is slow.

UI Platform Zero Deployment Familiar Environment No Hardware Reqs Much Better UI Behavior Network Utilization Offline Support And The Winner Is… – Network bandwidth is one of the challenges – Offline support is crucial – Developers familiar with windows forms programming

Data Access Our strategy:  Use DTO Entity-only classes, roaming between layers  Use DAO Strongly typed data retrieval / update layer  Use DBAL Generic, DB-centric layer BLBL DTODTO DAODAO DB Access Layer

Data Access We Looked at 4 alternatives:  Generic Dataset  Typed Dataset  Entity Framework  3 rd party ORM

Choosing The Right DAL We defined our key considerations:  Strongly typed interface  State Management  Network optimization  Learning curve

Data Access AltsStrongly Typed NetworkConcur.State Mgmt Data Contract SQL Flex.Dev Quantity Tool Support SupportLearning Curve Gen. Dataset XXVVXVXVVV Typed Dataset VVXVVXVXVVV EFVVXXVVXV VX 3 rd ORMVVXVX V XX The Typed dataset is less-risky, more flexible and more supported Need a solution to its network and interoperability problems

Tweaking the Dataset Typed DataSet XMLXMLDTODTO New Record Updated Record Deleted Record DTO

Tweaking the Dataset The results of the POC:

Enterprise Library

The Problem – System-wide logging – Flexible – Multiple outputs – Externally configured The Solution – Logging Application Block ?

Enterprise Library The Problem – Validation should be performed on the client & the server – Should be managed externally – Validation logic can change frequently The Solution – Validation Application Block With custom validation rules ?

Enterprise Library The Problem – Cross-cutting concerns should be separated from code – Should be managed externally The Solution – Policy Injection Application Block With custom handlers ?

Enterprise Library The Problem – Classes dependency is hard-coded – Should be managed externally The Solution – Unity ?

Offline Offline scenarios  Network Hiccups  Lack of network connectivity for mobile units Offline main challenges  Developing one system that supports online & offline  Supporting as much as possible “online functionality”  Security  Synchronizing Data

Offline Solution ?

Q & A

Related Sessions DEV314: Design Patterns – Learn From the Experience of Others Avi Rot

Summary CPR - Background Challenges in the Architecture Architecture Details

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