Hi there,
We were having some performance troubles using OpenLDAP and F5 load balance solution from BigIP at a high concurrent enviroment. We faced the problem for one month after I discovered that those problems didn't happen when applications was pointed directly to OpenLDAP server instead of load balance VIP. After a tcpdump analysis of the packages we realize that are too many ACK comming from each request.
Last week we solved the problem unsetting Nagle's algorithm on the load balance virtual server which was causing this issue.
So, if you look yourself on a similiar situation, please check the Nagle's algorithm on the F5 configuration!
Thanks,
Matheus Morais