Configuring an apache DS namespace : a pitfall

Apache Directory Server is a great free LDAP alternative.  There are number of good tutorials out there on how to configure Apache DS as a security namespace in IBM Cognos Configuration.  I won't be repeating all these steps, instead I'll paste a link below.

http://www.cornerstone.com.au/blog/view/installing-apacheds-for-cognos-bi-10-2-1

However, I would like to mention a pitfall when using more recent versions of Apache DS.  Most tutorials indicate that "uid" should be configured as unique identifier.  In some cases, IBM Cognos Configuration might come up with the error message below when testing the namespace.


Quite an annoying error message, as it doesn't give you too much detail.  Turns out you just have to revert the unique identifier property to its default ("dn") in order to make it work, just like in the screenshot below.


Did you know... you can change the sql of a query in report studio?

In report studio, you typically create queries by dragging the metadata into a query.  However, in some cases you're just not satisfied with the SQL that query generates, and you want to go and fiddle with it.

There's an easy way to do so, just click the query you want to edit, and click the "Generated SQL" property.  A window pops up that shows you the SQL, and click the "Convert" button at the bottom of the dialog.


In the dialog that follows, just change the query.


Click OK, and you will see that Report Studio changed the query in to a SQL query object.


Please note that running SQL directly in your report is a separate capability that can be activated or deactivated in the security settings in Cognos Administration.  The same thing can be done with MDX when creating a report on multidimensional data.

The message is : use caution when editing your own query.


Starting a dynamic cube from the command line

Doing maintenance on a dynamic cube in IBM Cognos 10 is quite straight-forward.  It's even possible to schedule some maintenance tasks, like stopping and starting a cube, and refreshing the data cache by creating an administrative task in the Administration module, and creating a schedule on top of it.

IBM Cognos Business Intelligence 10.2.1.1 Fix Pack 3 introduces a new and exciting tool called DCAdmin, in which you can do all of these tasks from the command line.  This allows an administrator to incorporate starting and stopping dynamic cubes from within another process.

For instance : stop cubes before an ETL load in order to save memory on the server, and starting them again after the ETL has completed.  Just one example of how such a tool might come in handy.

You can check out this article on the IBM support site for more information on how to use this tool.

http://www-01.ibm.com/support/docview.wss?uid=swg27040451

Good luck!

A word of caution when it comes to performance with BigInsights

Eventhough IBM BigInsights is a great platform to handle loads of data in different formats, connecting to Hive via IBM Business Intelligence deserves a word of caution.  IBM clearly states the following :

Quote :

The architecture of Hive is better suited for large query processing than handling many light queries because the set up time for a query is significantly higher compared to the most popular RDBMS. Therefore, consider scheduling pre-authored reports when ah-hoc analysis is not absolutely necessary. Scheduling reports in batches will benefit from Cognos Business Intelligence query service's cache management system, minimizing the amount of data that is fetched from BigInsights and significantly reducing report execution times.
If interactivity is required on large volumes of data, consider whether the analysis requirements can be met by scheduling Cognos Active Reports. If ad-hoc analysis is required, educate business users on how to perform multiple operations with a single drag-and-drop gesture. (Modelers should consider adding stand-alone filters and calculations to the package so that multi-click operations to define the filters/calculations can be avoided.)

What to conclude? Ad-Hoc reporting is a big nono.  You shouldn't expect Hive to have blazing performance when reporting on top of it.  That's especially true when there's only a limited amount of nodes serving the data.  Luckily IBM Cognos BI offers a range of possibilities in this respect as mentioned in the article in the URL below.

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