Full_Name: Henrik Bohnenkamp Version: >= 2.4.44, HEAD OS: Ubuntu 18.04, Coreos 7.5 URL: https://github.com/hbo/openldap-mdb-deref-problem Submission from: (NULL) (77.176.95.241)

This is a followup to http://www.openldap.org/lists/openldap-technical/201805/msg00065.html

When MDB is used as backend database and with large DITs (O(10^6)) with many alias entries (O(10^5)), search requests with deref=always and scope=sub will take prohibitively long. Servers with a high request rate might become utterly unresponsive. This problem is not present in the HDB backend.

In this issue I want to contribute two things: - a means to demonstrate the problem; this in the form of two scripts (bash/python) which set up a large test DIT and start two slapds (one HDB, one MDB) to allow easy comparisons of the performance - a patch to fix the problem

The patch is certainly not production ready (or, if it is, it needs still exhaustive testing to inspire confidence), however, I think it is far enough to at least discuss the approach.

Both the scripts and the patch, together with instructions how to use the former can be found here:

https://github.com/hbo/openldap-mdb-deref-problem

I am looking forward to discuss the patch.