Saturday, October 17, 2009

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

Sunday, October 4, 2009

FND_STATS vs DBMS_STATS

FND_STATS vs DBMS_STATS

I have been asked this questions many times. Shoud we use fnd_stats or should we use dbms_stats in 11i (or release 12). Most of the Apps DBAs you will face will say use fnd_stats. In fact Oracle also recommends to use fnd_stats in 11i E-Business Environments. But do you know what are the basic difference or you can say advantages or using FND_STATS over DBMS_STATS.
Here I have tried to compare the two…