KB9773: “Query engine encountered error: Unknown failed...Process died while waiting for reply” error message appears in MicroStrategy Web when executing reports with numerous columns and rows.

SYMPTOM:
The following error message appears in Strategy Web when users execute a report with numerous rows and columns:

"Query engine encountered error: Unknown failed. Unable to connect. Error type: System call error. Error communicating with connection, process. Process died while waiting for reply."

 

CAUSE:
This error occurs because the report requests a large amount of memory which can not be provided by the system. The memory of the request is based on the number of objects on the template, number of rows returned and data type. This error appears when the system cannot provide the amount of memory that has been requested.
 
ACTION:
Users may apply a filter to limit the number of rows returned for the report, or they can remove some of the attributes or metrics from the report.
 
WORKAROUND:
If users want to keep the report definition unchanged, perform the following steps:

1. Increase the page file size to allow for more virtual memory consumption.
2. Decrease the Cache Max RAM.
3. Decrease the Max Number of Caches.
4. Increase the Max Number of Report Rows.
5. Decrease the Working Set Size in Strategy Web under Preferences > Project Defaults > History List.
6. Decrease the Max RAM for Working Set Cache.

NOTE: If these steps do not fix this issue then the report definition should be modified.