Sun Microsystems Portal Server 6 - Manual (Page 86)

Portal Server System Communication Links
86 Portal Server 6 2005Q1 • Deployment Planning Guide
• Gateway . A load balancer used with the Gateway detects a failed Gateway
component and routes new requests to other Gateways. A load balancer also
has the ability to intelligently distribute the workload across the server pool.
Routing is restored when the failed Gateway recovers. Gateway components
are stateless (session information is stored on the client in an HTTP cookie) so
rerouting around a failed Gateway is transparent to users.
• Portal Server . In open mode, you can use a load balancer to detect a failed
server component and redirect requests to other servers. In secure mode,
Gateway components can detect the presence of a failed server component and
redirect requests to other servers. (This is valid as long as the web container is
the Web Server.)
• Directory Server . A number of options make the LDAP directory highly
available. See “Building Modules and High Availability Scenarios” on page 90
for more information.
• Netlet and Rewriter Proxies . In the case of a software crash, a watchdog
process automatically restarts the proxies. In addition, the Gateway performs
load balancing and failure detection failover for the proxies.
Portal Server System Communication Links
Figure 5-1 on page 87 shows the processes and communication links of a Portal
Server system that are critical to the availability of the solution.