On Fri, Mar 29, 2019 at 01:38:30PM +0000, ondra@openldap.org wrote:

Full_Name: Ondrej Kuznik Version: re24/master OS: URL: https://github.com/mistotebe/openldap/tree/its9001 Submission from: (NULL) (82.10.24.68)

If a client has thousands or more requests in flight at the same time, it has to look up the right request every time it receives a response. As the requests are tracked in a doubly-linked list, lookup tends to take O(n) steps whichever direction we take and things generally get out of hand from there on.

The linked branch puts them into a TAvl for quicker lookup, with another commit to let people test as (t)avl code is part of liblutil at the moment.

A trivial program to expose this behaviour is available at ftp://ftp.openldap.org/incoming/searcher.c

The same program takes under a second to handle 100000 searches for cn=monitor and children when linked to the patched libldap.