Reproducer is in DS 48287.

It requires IPA master/client, but it is easy to reproduce (in a couple of hours).

[root@ipaqa64vmf ~]# rpm -qa | grep 389-ds
389-ds-base-libs-1.2.11.15-71.el6.x86_64
389-ds-base-1.2.11.15-71.el6.x86_64

Verification steps:
1. Install IPA Master

2. Install IPA Replica

3. Enable core dump: 
 - yum install abrt
 - sysctl -w fs.suid_dumpable=1
 - In /etc/sysconfig/dirsrv, change 'ulimit -c' to unlimited

4. Iterate the provided script 'steps.sh' on the master:
[root@ipaqa64vmf ~]# cat steps.sh
#!/bin/sh

MASTER=ipamaster.redhat.com
REPLICA=ipareplica.redhat.com

CPT=0
EXT=${1:-}
if [ -z "${EXT}" ]
then
        EXT=$RANDOM
fi
kinit admin
ssh root@$REPLICA /usr/sbin/ipa-replica-manage re-initialize --from=$MASTER -p Secret123
while [ $CPT -lt 10 ]
do
        ipa user-add --first=fi --last=la user_${EXT}_${CPT}
        CPT=`expr $CPT + 1`
done

echo
echo
echo
sleep 10
CPT=0
while [ $CPT -lt 10 ]
do
        ldapsearch -D "cn=directory manager" -w Secret123 -h $REPLICA -p 389 -LLL -b"cn=users,cn=accounts,dc=redhat,dc=com" "uid=user_${EXT}_${CPT}" dn
        CPT=`expr $CPT + 1`
done

[root@ipaqa64vmf ~]# ./steps.sh
Password for admin.ENG.BOS.REDHAT.COM:
root.lab.eng.bos.redhat.com's password:

-------------------------
Added user "user_25018_0"
-------------------------
  User login: user_25018_0
  First name: fi
  Last name: la
  Full name: fi la
  Display name: fi la
  Initials: fl
  Home directory: /home/user_25018_0
  GECOS field: fi la
  Login shell: /bin/sh
  Kerberos principal: user_25018_0.ENG.BOS.REDHAT.COM
  Email address: user_25018_0.eng.bos.redhat.com
  UID: 983000022
  GID: 983000022
  Password: False
  Kerberos keys available: False
-------------------------
Added user "user_25018_1"
-------------------------
...
-------------------------
Added user "user_25018_9"
-------------------------

dn: uid=user_25018_0,cn=users,cn=accounts,dc=idmqe,dc=lab,dc=eng,dc=bos,dc=red
 hat,dc=com

dn: uid=user_25018_1,cn=users,cn=accounts,dc=idmqe,dc=lab,dc=eng,dc=bos,dc=red
 hat,dc=com
...
dn: uid=user_25018_9,cn=users,cn=accounts,dc=idmqe,dc=lab,dc=eng,dc=bos,dc=red
 hat,dc=com


5. Check for the error message:
[root@ipaqa64vmf log]# grep DB_LOCK_DEADLOCK dirsrv/slapd-PKI-IPA/errors
[root@ipaqa64vmf log]# echo $?
1

Hi Thorsten,

this fix is included in 389-ds-base-1.2.11.15-72.el6_7:
https://brewweb.devel.redhat.com/buildinfo?buildID=485184

It's targeted for BU#6.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-0737.html