(ITS#6919) "Weekly" crashes of OpenLDAP 2.4.22 using syncrepl master/master

[jarl@dallur.com]

Full_Name: Jarl Stefansson
Version:  2.4.22 
OS: Centos 5.5
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (81.15.35.75)


Two servers running OpenLDAP in master/master using syncrepl, roughly once per
week one of the servers stops responding to new connections, I tried logging
with loglevel=1 and this is all I got, all suggestions and comments
appreciated.

This is most likely a "load" related problem since we never experience this
problem in the testlab, only production.:

Apr 23 20:36:37 ldap01 slapd2.4[32233]:
bdb_dn2entry("macaddress=1\2C6\2C00:00:00:00:00:01,ou=xxx,ou=xx,o=xxxx") 
Apr 23 20:36:37 ldap01 slapd2.4[32233]: =>
bdb_dn2id("macaddress=1\2C6\2C00:00:00:00:00:01,ou=xxx,ou=xx,o=xxxx") 
Apr 23 20:36:37 ldap01 slapd2.4[32233]: <= bdb_dn2id: get failed: DB_NOTFOUND:
No matching key/data pair found (-30988) 
Apr 23 20:36:37 ldap01 slapd2.4[32233]: => bdb_dn2id_add 0x2fed7:
"macaddress=1\2C6\2C00:00:00:00:00:01,ou=xxx,ou=xx,o=xxxx" 
Apr 23 20:37:44 ldap01 slapd2.4[32233]: slap_listener_activate(8):  
Apr 23 21:35:42 ldap01 slapd2.4[32233]: connection_close: conn=1025 sd=16
Apr 23 21:55:42 ldap01 slapd2.4[32233]: connection_close: conn=1022 sd=17
Apr 23 21:55:42 ldap01 slapd2.4[32233]: connection_close: conn=1037 sd=18
Apr 23 21:55:42 ldap01 slapd2.4[32233]: connection_close: conn=1038 sd=20
Apr 23 21:55:42 ldap01 slapd2.4[32233]: connection_close: conn=1039 sd=25

Apr 24 12:02:23 ldap01 slapd2.4[32233]: daemon: shutdown requested and
initiated. I have two Centos 5 servers running Openldap 2.4.22 with
master/master syncrepl setup, 
Apr 24 12:02:23 ldap01 slapd2.4[32233]: connection_close: conn=1005 sd=21 
Apr 24 12:02:23 ldap01 slapd2.4[32233]: slapd shutdown: waiting for 59
operations/tasks to finish 
Apr 24 12:02:34 ldap01 slapd2.4[26503]: bdb_db_open: database "": unclean
shutdown detected; attempting recovery. 
Apr 24 12:02:35 ldap01 slapd2.4[26503]: slapd starting 


---------------------- Relevant Config
------------------------------------------------
moduleload     syncprov.la
TLSCertificateFile      /etc/pki/tls/private/ldap.pem
TLSCertificateKeyFile   /etc/pki/tls/private/ldap.pem
TLSCACertificateFile    /etc/pki/tls/private/ldap.pem

serverID        001
database        bdb
sizelimit              50000
cachesize 10000
checkpoint 256 5


syncrepl        rid=001
                provider=ldap://10.10.10.10:389
                bindmethod=simple
                binddn="uid=xxxxrep,ou=xxxxxx,o=xxxxxx"
                credentials=MyPassword
                searchbase="o=xxxx"
                schemachecking=on
                sizelimit="unlimited"
                timelimit="unlimited"
                type=refreshAndPersist
                interval=00:00:00:10
                retry="5 5 60 +"
                attrs="*,+"

mirrormode on
overlay syncprov
syncprov-checkpoint     100     10
syncprov-sessionlog     100

idletimeout 3600
threads 32