Sun Microsystems Portal Server 6 2005Q1, Руководство по планированию

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Portal Server and Access Manager on Different Nodes
Chapter 5 Creating Your Portal Design 109
Figure 5-9 shows a configuration for maximum horizontal scalability and higher
availability achieved by a horizontal server farm. Two Portals Servers can be
fronted with a load balancer for maximum throughput and high availability.
Another load balancer can be put between Portal Servers and Access Managers to
achieve authentication and policy processes as a load distributor and failover
mechanism for higher availability.
In this scenario, Blade 1500s can be utilized for Portal Services to distribute the
load, similar Blades can be used to host Access Manager Services and Directory
Services respectively. With the architecture shown in
Figure 5-9 a redundancy of
services exists for each of the product stack, therefore, most of the unplanned
downtime can be minimized or eliminated.
However, the planned downtime is still an issue. If an upgrade or patch includes
changes to the Directory Server software schema used by the Access Manager
software, all of the software components must be stopped to update the schema
information stored in the Directory Server. However, updating schema
information can be considered a fairly rare occurence in most patch upgrades.
Figure 5-9 Two Portal Servers and Two Access Managers
When two instances of Portal Server and Access Manager servers share the same
LDAP directories, please use this workaround for all subsequent Portal Server,
Access Manager, and Gateways:
Portal
Server
Load
Balancer
Directory
Server
Directory
Server
Portal
Server
Load
Balancer
Access
Manager
Server
Access
Manager
Server