Slapd tuning:
"threads": This directive sets the number of threads that slapd uses to
process requests. What this value should be I've generally found to be
a function of the number of "real" cores on the system. I.e., on a 2
CPU box with one core each, I set this to 8, or 4 threads per real core.
This is a "read" maximized value. The more threads that are configured
per core, the slower slapd responds for "read" operations. On the flip
side, it appears to handle write operations faster in a heavy write/low
read scenario.