Bug 1056987

Created attachment 854273 [details]
Unexpected errors in KPIs

Description of problem:
The mechanism which was recently implemented to prevent dashbuilder against CPU or memory intensive requests (see Bug 1024803) is causing some problems when loading KPI panels. Sometimes KPI data are not loaded within the memory constraints and the KPI panel displays UNEXPECTED ERROR (see screenshot).

I feel, that the situation when KPI fails to load dataset because of broken constraint, the panel should display some more user friendly message (in the spirit of "Failed to load data from the server: running out of memory")


Version-Release number of selected component (if applicable):
BPMS 6.0.0 CR1

How reproducible:
It happens always when using IBM JDK 1.6 with defaul memory settings (it has probably higher memory consupmtion)

But I can reproduce easily also locally on my machine with Oracle JDK 1.7 by artificially lowering heap size of the EAP.

Steps to Reproduce:
1. Lower the JVM Heap memory settings of the EAP by going to $EAP_HOME/bin/standalone.conf
and replace JAVA_OPTS="-Xms1303m -Xmx1303m -XX:MaxPermSize=256m -Djava.net.preferIPv4Stack=true"

with something like (or a bit higher to still enable server to start and deploy applications correctly):

"JAVA_OPTS="-Xms200m -Xmx200m -XX:MaxPermSize=256m -Djava.net.preferIPv4Stack=true"

2. Go to some dashbuilder page with KPIs and try reloading the page several times or try some drill down operations.

Actual results:
Very soon some KPI fails to load and you will see UNEXPECTED ERROR as in the screenshot.

Expected results:
Since this is a controlled situation I would rather see some more user friendly message displayed in the KPI panel not to scare business users. As is for example the case in the DataProvider panel: When user tries to load dataset which is too large,the user friendly warning 'Data set load time has been exceeded = 10.0s' is displayed and loading of data is stopped.