I installed slapd in Docker, and it was using 712 MB memory even with a few entries.

The fix is to run slapd after ulimit -n 1024, eg.

#!/bin/bash

ulimit -n 1024

slapd -d3

Starting slapd with such a wrapper script has improved the situation considerably:

$ docker stats –no-stream –format \
“table {{.Container}}\t{{.MemUsage}}” slapd

CONTAINER MEM USAGE / LIMIT
slapd 3.855MiB / 1.944GiB