henrik.bohnenkamp@ionos.com wrote:

On Thu, Jun 27, 2019 at 10:34:19PM -0700, Quanah Gibson-Mount wrote:

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--On Sunday, April 07, 2019 10:15 AM +0000 henrik.bohnenkamp@ionos.com wrote:

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On Thu, Apr 04, 2019 at 05:32:16PM +0100, Howard Chu wrote:

Had a customer who was hitting this issue try out these patches -- It greatly decreases the search time (from unknown/infinite to 1 minute). Unfortunately slapd then segv's. Working on getting a test database to reproduce the issue with for a good backtrace.

oh, that's too bad. I'd be happy to participate in the bug hunt. May I ask: which version did your customer use? I have modified the patch to work with the recent changes on master, but I did not dig in very deep to understand these changes. So I must admit that these modifications to the patch are completely untested (except the tests in the tests subdir).

Things might work better with the 2.4.46/47 patch, if that is an option for your customer.

Wrt getting a test-tree, maybe the python script I have in the github repo for the patch can provide one. (https://github.com/hbo/openldap-mdb-deref-problem/blob/master/scripts/write_...)

I'm of course very interested to keep this patch alive, so if you have details on the segv, please let me know.

Fyi, on our problematic test database with 11M entries and 3.7M aliases, a search with -a always , starting from the DB suffix, took 4 minutes without this patch, and 1235 minutes with this patch.

Needless to say, that's not looking good. Still checking other test cases.