The QlikView Distribution Service Cluster is meant to load balance task executions. Tasks are instead being executed in paralell on all nodes, leading to failures. Environment:
QlikView 11.20 all versions
This should not occur in 12.00 to 12.20 (November 2017) and up
The QlikView Distribution Service clusters communicate by reading from, and writing to, the .xml files in their shared Distribution Service Application Data folder. With a too large task list, or too much latency to handle the frequent read and write actions, configuration changes may be necessary to ensure they are able to correctly identify which one of them is currently the most loaded machine. Otherwise both will run the task.
Improvements were made in QlikView 12.00 and up, especially during the 12.10 and 12.20 releases, which should already be preventing this behaviour.