As the Java Virtual Machine runs within the NDSD Processes, in some cases where larger amounts of Threads were necessary in the NDS Thread Pool, the increased amount of memory consumed by the large number of NDS Threads could push NDS Thread Stack to the limit for that amount of memory that could be allocated to NDSD.
The ability to configure the stack size for NDS Threads, allows some memory to be freed for higher number of NDS Threads or other memory usage.
Prior to EDirectory 8.7.3.9, the stack size for NDS Threads was hard coded to 4 MB. Valid settings are now 1, 2, 3 or 4 MB.