Designing the Physical Architecture

Objectives Understanding client server and n-tier architectures Server farms

System Architecture (Introduction) Client (PC / tablet / mobile /) server (minicomputer / mainframe) Web-based client (OFBiz) Thick client (SAP NetWeaver) Two-tiered architecture Client / server / database Three tiered architecture

Client / Server / Illustration

Three-tier (Illustration) Application Server Database Server

System Architecture (Introduction) As systems grow, a single computer is not enough Load balancing servers route traffic to application servers Application servers run the enterprise application OFBiz, SAP We call these Server Farms (and Web Gardens)

System Architecture (Introduction) Server farms typically use a backend database (centralized) The database can be federated

Complex Load Balanced Database Server Load Balancing Servers Clients Application Servers

Physical Architecture Functional Requirements Financial factors Cost of development, infrastructure, and maintenance Performance factors Scalability Fault tolerance Speed The cloud Internet of things

Non-functional Requirements Requirements for data conversion and data integration Portability and flexibility How strict are the hardware and software requirements? OFBiz will run on anything that runs Java, which is just about anything Maintainability Operational tasks / backups, etc.

Establishing Performance Requirements Speed Define expected response time Run simulated benchmarks to test expected response time Capacity requirements How “expandable” are the systems we are buying Availability and reliability What reliability characteristics do we need

Benchmarking We need to estimate performance There are several benchmarks to do this http://www.tpc.org/information/benchmarks.asp TPC-C is a transactional benchmark http://www.tpc.org/tpcc/results/tpcc_results.asp?orderby=hardware OFBiz has some benchmarking tools “built in” to simulate load http://www.hotwaxsystems.com/ofbiz/apache-ofbiz-performance-benchmarking/

Building Hardware and Software Specifications CPU number and speed Memory IO Disk / SAN / NAS Network

Facility Electrical requirements Cooling and humidification requirements Physical footprint

Physical Security This is really the subject of your data security course Controlling physical access Firewalls Proxy Web servers in the DMZ Database lives behind the firewall

Cultural and Political Ecosystems It’s the age old problem of adoption and acceptance

Modeling the Implementation We have a UML diagram for that too Deployment diagrams depict software and hardware components Network diagrams depict the physical network architecture

UML Deployment Diagrams (Parts) Symbols to show the system parts Client, server, mainframe, network, database, etc… Parts Nodes are computational resources Artifacts are pieces of software or databases OfBiz Communication paths show associations between nodes

Network Model There is no specific UML diagram to model the network Instead, we use deployment diagrams.

Network Model