Hi!

Updates:

1. Even when I add the missing “olcOverlay: {0}syncprov” it does not change a thing
2. When using slapmodify instead of ldapmodify to do the change offline, it succeeds and slapd starts after that
3. Adding a syncprov overlay to another database online also worked.

Kind regards,

Ulrich Windl

From: Windl, Ulrich <u.windl@ukr.de>
Sent: Thursday, April 3, 2025 10:52 AM
To: openldap-technical@openldap.org
Subject: [EXT] Adding syncprov overlay to cn=config seems to freeze the server

Hi!

I‘m trying to script a reconfiguration of out OpenLDAP servers, also changing the replication details.

After dropping the old syncrepl overlay, I tried to add a new one like this:

dn: olcOverlay={0}syncprov,olcDatabase={0}config,cn=config

changetype: add

objectClass: olcOverlayConfig

objectClass: olcSyncProvConfig

I deliberately did not add more specific attributes, because I wanted to add them later.

However I forgot to set olcOverlay.

The point is that both, ldapmodify and slapd become unresponsive using that LDIF, at least when provided as

ldapmodify -Y EXTERNAL -H ldapi:/// <<LDIF

…

LDIF

Is this a bug?

Seen in OpenLDAP 2.5 provided by SLES15 SP6.

From a coredump I forced, I see that the threads are all waiting, using one of these:

__pthread_clockjoin_ex

pthread_cond_wait

__pthread_clockjoin_ex

Kind regards,

Ulrich Windl