Configure OpenLDAP Replication to continue Directory

Configure OpenLDAP Replication to continue Directory service if OpenLDAP master server would be down. OpenLDAP master server is called "Provider" and OpenLDAP Slave server is called "Consumer" on OpenLDAP.
[1]	Configure Basic LDAP Server settings on both Provider and Consumer, refer to here.
[2]	Configure LDAP Provider. Add syncprov module.

[root@dlp ~]#  vi mod_syncprov.ldif # create new dn: cn=module,cn=config objectClass: olcModuleList cn: module olcModulePath: /usr/lib64/openldap olcModuleLoad: syncprov.la [root@dlp ~]#  ldapadd -Y EXTERNAL -H ldapi:/// -f mod_syncprov.ldif  SASL/EXTERNAL authentication started SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth SASL SSF: 0 adding new entry "cn=module,cn=config" [root@dlp ~]#  vi syncprov.ldif # create new dn: olcOverlay=syncprov,olcDatabase={2}hdb,cn=config objectClass: olcOverlayConfig objectClass: olcSyncProvConfig olcOverlay: syncprov olcSpSessionLog: 100 [root@dlp ~]#  ldapadd -Y EXTERNAL -H ldapi:/// -f syncprov.ldif  SASL/EXTERNAL authentication started SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth SASL SSF: 0 adding new entry "olcOverlay=syncprov,olcDatabase={2}hdb,cn=config"

[3]	Configure LDAP Consumer.

[root@slave ~]#  vi syncrepl.ldif # create new dn: olcDatabase={2}hdb,cn=config changetype: modify add: olcSyncRepl olcSyncRepl: rid=001    # LDAP server's URI provider=ldap://10.0.0.30:389/ bindmethod=simple    # own domain name binddn="cn=Manager,dc=server,dc=world"    # directory manager's password credentials=password searchbase="dc=server,dc=world"    # includes subtree scope=sub schemachecking=on type=refreshAndPersist    # [retry interval] [retry times] [interval of re-retry] [re-retry times] retry="30 5 300 3"    # replication interval interval=00:00:05:00 [root@slave ~]#  ldapadd -Y EXTERNAL -H ldapi:/// -f syncrepl.ldif  SASL/EXTERNAL authentication started SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth SASL SSF: 0 modifying entry "olcDatabase={2}hdb,cn=config" # confirm settings to search datas [root@slave ~]#  ldapsearch -x -b 'ou=People,dc=server,dc=world'  # People, server.world dn: ou=People,dc=server,dc=world objectClass: organizationalUnit ou: People ... ...

[4]	Configure LDAP Client to bind LDAP Consumer, too.

[root@www ~]#  authconfig --ldapserver=dlp.server.world,slave.server.world --update