Blog dedicated to Oracle Applications (E-Business Suite) Technology; covers Apps Architecture, Administration and third party bolt-ons to Apps

Monday, June 30, 2008

Using Big IP hardware load balancers with 11i and R12

All our Production instances are load balanced on web tier. We have multiple app tiers for each instance on which Apache and forms is running. The user point of entry is the load balancer URL which further redirects the traffic to the individual app servers. Oracle uses BigIP load balancer on their internal Global Single Instance also. Here are some very good metalink notes which give you a good overview:

380489.1 Using Load-Balancers with Oracle E-Business Suite Release 12 (Relevant for 11i too)
217368.1 Advanced Configurations and Topologies for Enterprise Deployments of E-Biz Suite 11i
601694.1 How To Check Session Persistence On a BigIP F5 Load Balancer
456906.1 11i/R12 How to Debug "Transaction Context Is Lost"
387306.1 Random error Your login session has expired when using Load Balancing

When a hardware load balancer is used, the context file variables which need to be changed are:

s_webentryurlprotocol http or https
s_webentryhost load balancer hostname
s_webentrydomain load balancer domain name
s_active_webport load balancer port
s_login_page load balancer url
s_external_url load balancer url

Load balancer settings:

persistence timeout = 1 day
persistence type = cookie based persistence


Anonymous said...

We are using Oracle 11i with F5 LTMs and are getting Page Expired error when we us the back button in IE 6 & 7 - The developers are sure that it is a F5 issue. I've followed all of the recommendations published by F5 use with Oracle and it still continues - will these context settings in Oracle correct this problem?

Vikram Das said...

Hi Anonymous,

Your developers may be correct. Please check what is the idle timeout configured inside BigIP. Metalink Note 601694.1 has screenshots of BigIP configuration and navigation of where exactly the values need to be changed. Also refer to Metalink Note:372051.1 which has additional documentation.

- Vikram

Anonymous said...

I did check the F5 configuration against these documents and the settings match - I noticed that there are some recommended patches and settings for Oracle - could any of these cause Page expired issues? I notice that the page expired issues do not happen on all pages. The pages with problems look like forms - I also notice that it does not happen with firefox unless I turn off caching.