As usual, I got caught in a strange problem which one of our customers was facing – this time it had to do with user folders in the catalog.
As many of you may be aware, when 11g came out, one of the things which changed was that instead of all the user directories being stored directly in the <catalog_name>/root/users/username path as in 10g, the users were now stored in <catalog_name>/root/users/<first_3_char_of_username>/<username>.
(This was done in part to reduce the number of folders created directly under the users folder and for ease of management. One of the larger banking customers I work with has over 12,000 users in the user directory and this does become unusable, so I applaud the idea.)
Now the problem happened when there was a problem with the BI Production Application server and all the users were temporarily redirected to a different environment while the Production Application server was being patched. What was noticed was that the folder structure I described above was not being followed in the other environment.
Thus, the Production Application server structured the catalog like this:
Whereas the Disaster Recovery Application server structured the catalog like this:
This was causing a disruption for users because their favorites, dashboard prompted links and selections etc were now showing up. Rather, on logging into "My Dashboard", most users would see another folder of their name.
(Note: For this customer, the usernames were 3 characters to begin with, so these used to get repeated in the parent and actual user folder)
On further investigation, I realized that somewhere between 11.1.1.6.0 (where the catalog was originally upgraded) and 11.1.1.6.8 the current version on the DR server, the default value of the HashUserHomeDirectories had changed from 3 to 0. This was causing the variance.
The HashUserHomeDirectories setting addresses file system limitations and hashes the users' home directories. For example, for the user named Steve, the logical folder "/users/steve" becomes the physical tree on the disk "/users/st/steve" if this value is set to 2.
Sure enough, on changing the HashUserHomeDirectories value to 3, the system started working as expected again. The steps to do this are to insert the following line inside the CATALOG tags in the instanceconfig.xml file for your server.
<HashUserHomeDirectories>3</HashUserHomeDirectories>Voila, similar behaviour to earlier versions of 11g and users can login to their accounts and the personalization remain.
Environment Information:
Oracle BI Version: 11.1.1.6.7 (Build 121219.1259 64-bit)
Operating System: Windows Server 2008 R2 Enterprise