ASP 3.0 The Complete Reference
Chapter 31
Planning a System Architecture (Outline)
Create an Application Architecture that is Appropriate to
the requirements
Three Tier Balance
Figure 1:
Three Tier balance
Identifying the appropriate place for the work to be done
Client Focus
Web Server Focus
Database Focus
Caching
Script vs ISAPI
Increase Scalability with Clustering and Load Balancing
Cluster Service
File/Print Services
Database Services
Messaging Services
Figure 2:
Cluster Diagram
How It Works
Network Load Balancing
Web Farms
Figure 3:
NLB Diagram
How it Works
runs as a Network Driver
uses a distributed filtering algorithm
not Round Robin DNS
ClusterSentinel in Resource Kit 2000
Application Center 2000
Microsoft Application Center 2000 is a new product
with Windows DNA 2000. Application Center 2000 provides centralized management
of a network cluster from a single desktop by providing deployment, management
and diagnostic tools. It addresses the need for organizations to run their
Internet applications on a cluster of servers, rather than on a single machine.
Web front-end load balancing for scalability
Load balancing presents a single service name to clients
in the form of a virtual IP address and then distributes the clients across a
set of servers that implement the service.
There are three principal techniques for service load
balancing:
- Round
Robin DNS (RRDNS).
- Intelligent
IP load balancing with a dedicated third-party outboard box.
- Intelligent
IP load balancing within the servers, using NLBS in Windows 2000.
SMP Support
Benefits
High Availability
Failover
Scalability
Manageability
Challenges
Session Support
What you Need
Windows 2000 Advanced Server
Windows 2000 DataCenter
File replication services.
The Example Load Balanced Web Farm with Clustered Database
System Architecture
Figure 4:
System Diagram
Session Handling
Session Alternatives
Centralized State Manangement
Active Directory
Personalization Server
Stateless Web Application
Session Aware Load Balancing
Software Routing
Hardware
would require a second login if server fails
Using Active Directory in Place of Sessions
persistent Data Store
Keeping Profile Info
Figure 5:
Remembering Preferences
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GLOBAL ASA
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Putting Values into a Property
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Customizing Active Directory for Your Application
Deciding when an Existing Schema does not meet your needs
Remember this is not a trivial matter
must obtain an OID from a registration authority
Making a Schema Change
Adding a custom property to the User Directory
Caution about doing this
Figure 6:Active
Directory Interface