Home > Workload Solutions > Oracle > White Papers > Solution Insight: Oracle Analytics Server with Dell PowerFlex Infrastructure > Web tier (LBR and OHS)
This tier consists of a pair of load balancers (LBR) and two or more physical web servers or hosts that receive the initial request from the users.
LBR can be either hardware devices or software applications. It provides security enhancements by allowing customers to configure external facing virtual server names (URLs) that users enter to connect to OAS. LBR, in turn, will route these requests to one of the web servers (WEBHOST1, WEBHOST2, WEBHOSTn) by using a load balancing algorithm. LBR uses Network Address Translation (NAT) to map the URL requests to the appropriate internal application (OAS) URLs. LBR can also help increase performance to the architecture by terminating or off-loading the SSL requests.
Although traffic from LBR can be routed directly to the application servers (WebLogic Servers (WLS) and OAS), it is recommended to deploy web servers (Oracle HTTP Servers (OHS)) in the web-tier. Deploying servers in the web tier offers several advantages such as faster fail-over if a WLS instance fails, more security with a public DMZ, and faster delivery of static content. OHS is installed and configured on its own domain on each host. Each OHS instance is an independent unit, which makes it easier to configure and maintain.