Adobe LCDS tomcat running with 100% CPU

We  have just experienced a problem with Adobe Live Cycle Data Services ES 2.6 using 100% of the CPU.

Restart of the tomcat service did no good, unless I also restarted the Flash client. Then it was running without problems for a while, before it once again rocketed up to a 100% CPU load.

After some debugging we found the cause to be non-unique data rows to the SQLAssembler. 

A database change led to a view was missing a join, which in turn caused the view to return a numerous duplicate rows.  LCDS did not handle this very well, but was luckily easy to fix, once the bug was identified.

Step 2 - Understand LCDS' folders

If you are completely new to Adobe LiveCycle Data Services and Java application servers in general, I hope this might be a few guiding lights in the dark. What is a Java Application Server? Think of it as a web server (IIS if you like), but with lots of built in functionality, modules and library function that your "web pages" can use. LiveCycle Data Services (LCDS) is one such a library of functionality. In this turn-key installation of LCDS, we use Tomcat as the Java application server. So LCDS runs within Tomcat. Java application servers are basically folder and file based, and at first glance it is difficult to know what each folder is for and where to put your own applications. Where do I start? Where do I put my stuff? First the application server Tomcat:

C:\Adobe_lcds\tomcat	The root folder for Tomcat, your Java application server
C:\Adobe_lcds\tomcat\bin	Directories for Tomcat startup/shutdown scripts
C:\Adobe_lcds\tomcat\conf	Configuration files for Tomcat
C:\Adobe_lcds\tomcat\work	Hands off! Tomcat's own temp (working) folder
More info about Tomcat at Jajakarta.org

And now what we are interested in... LCDS:

C:\Adobe_lcds\tomcat\webapps	Root folder for LCDS.
C:\Adobe_lcds\tomcat\webapps\lcds-samples	Adobe's sample applications. http://localhost:8400/lcds-samples/
C:\Adobe_lcds\tomcat\webapps\lcds	Template folder for your own apps. Copy this, and create your own based on this template. Keep this unspoilt if you need to start from scratch. http://localhost:8400/lcds/
C:\Adobe_lcds\tomcat\webapps\ds-console	The console / status reports for the Adobe LiveCycle Data Services web applications. http://localhost:8400/ds-console/
More info about LiveCycle Data Services configuration at Adobe

Next we will look at the database sample that came with LCDS. [Main article] [Next] [Previous]