Re: (ITS#8875) [Patch] Performance problems in back-mdb with large DITs and many aliases

[henrik.bohnenkamp@ionos.com]

On Thu, Jun 27, 2019 at 10:34:19PM -0700, Quanah Gibson-Mount wrote:
> --On Sunday, April 07, 2019 10:15 AM +0000 henrik.bohnenkamp@ionos.com
> wrote:
> 
> > 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_tree.py)

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

Henrik


> 
> --Quanah
> 
> 
> --
> 
> Quanah Gibson-Mount
> Product Architect
> Symas Corporation
> Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
> <http://www.symas.com>

-- 
Dr. rer. nat. Henrik Bohnenkamp

Senior Sysadmin
IT Operations Monitoring & Infrastructure

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