Huge report not rendering in HTML output version

[BristolSmithy]

Hi, I've come across a bit of a bizarre problem.

I've got some reports that are pretty enourmous (100 columns and up to 1 mil rows, although we've set the run option on the report to render 100 rows at a time).  The issue is that the reports will not render in html when we try and run it for anything over 1,000 rows.  The report runs for ages and then either the IE window stops repsonding or it renders with a blank page (with next page links at the bottom of the report but absolutely no data/headers etc)...  However, if we run as a CSV or Excel then it works fine.

We've raised it with COGNOS and they're still looking into it.  There initial thought was that it would be related to the temp folder, but this has lot's of space.

Anybody come across this before and find a solution?

[RobsWalker68]

Hi,

Wow, thats a lot of page down clicks to get to the bottom of the report.  I would say revisit the user requirements but that's your requirement afterall, although I'm dying to know what you need it for  ;)

I don't know your environment so this is more of a shopping list instead of a structured response and I guess Cognos support will get to the bottom of it as you can try the config changes they suggest but off the top of my head:

Are there any governor settings in the framework or report that limit the execution time?

With an interactive HTML report this will be a high affinity request and therefore the page down will run on the same report server as requested the report.  Cognos will cache the results received so far and maintain a dbcursor.  Each page down request will move the dbcursor on.

Are you able to monitor what the database is doing?  Is it dropping the connection due to any timeout values?

Don't have more than 2 IE sessions open at the same time as this can cause issues with asynchronicity

Do you need to configure the asynchronous timeout value on Cognos?  Note below:

"If you have a high user load (over 165 users) and interactive reports are running continuously
in a distributed installation, you may want to increase the asynchronous timeout setting to avoid getting error messages. The default is 30000.

To resolve this problem:

Steps
1.Go to the following directory:

c8_locationwebapps/p2pd/WEB-INF/services/.

2.Open the reportservice.xml file in a text editor.

3.Change the async_wait_timeout_ms parameter to 120000.

4.Save the file.

5.Restart the service"

For large reports, as noted by IBM support, temporary files can be created.  You can amend the cognos configuration so that it only uses memory in report creation, however depending on the size of your reports this could siginificantly impact your environment especially if it is a production one and therefore if you wish to try it out make sure its on a test environment.  If you still have an issue though you may be able to discount physical disk space.  Note below:

"Using memory instead of disk space is particularly beneficial in cases where temporary files are created on IBM Cognos 8 servers,
causing information transfer from memory to disk. You can monitor the occurrence of temporary files using the c8_location\temp directory.
Monitor this folder during report processing periods to determine whether temporary files are created as cclvpage*.tmp.

To ensure that IBM Cognos 8 uses memory instead of disk space, in the rsvpproperties.xml file,

edit the VirtualMemoryDiagnostics property to use unlimited memory (value = 2) rather than limited memory (value = 0):

<property>VirtualMemoryDiagnostics</property><value type="long">2</value>

Note: Remove the comment to enable the VirtualMemoryDiagnostics property.
"

Kind Regards

Rob







 

[Lynn]

I am also wondering what type of beast-user could reasonably consume such a massive amount of data, particularly in an interactive HTML mode. Lots of people use Cognos to extract data to Excel or CSV for other automation purposes although it isn't really an ETL tool, but if that was your intent then why the need for HTML?

Have you tried to run as HTML and save the output? Might offer an alternative approach to satisfy your requirement and/or additional troubleshooting information.