OUD Instances Out of Sync ??

                 In the world of replication between nodes across data centers, there are chances of having some node failures due to power outages, disk issues or for several other reasons. These issue might result in the data going out of sync between the nodes.

So how do we fix it ???

            There are several approaches that we usually take depending on the amount of data lost, data quality etc and several other factors.. Now in this post we are going to sync the data using the Manual approach assuming there is only minor loss of data which can be fixed manually...

Below are the high level steps which we are going to take in order to fix this data inconsistency.

• Find the OUD server which is stable. In this post, referring as oud1 in the post. 
• Find the OUD server which is out of sync with stable server. refering as oud2. 
• Export entries from oud1 and oud2 and compare
• Export missing entries and data from oud1
• Import the missing entries and data into oud2

Environment:

• OUD 11.1.2.3 
• RHEL 6 

Steps:

• Export entries from oud1 using ldapsearch

Run below ldapserach command to write entries into file. by default ldapsearch utility will be available in <oud_instance>/bin folder. Here OUD1 is the best instance and OUD2 is the instance which is out of sync.

ldapsearch -h <oud1_hostName> -p <Port> -D "cn=Directory Manager" -j <Password_File> -b "dc=base,dc=com" "objectclass=*" dn | sort > oud1_entries.txt


Sample:-(oud1_entries.txt):-
dc=com
dc=base,dc=com
dn: cn=group1,ou=users,dc=base,dc=com
dn: cn=group2,ou=users,dc=base,dc=com
dn:.....
dn:.....
dn: cn=Test User1,ou=users,dc=base,dc=com
dn: cn=Test User2,ou=users,dc=base,dc=com
dn:.....
dn:.....

P.S: When you open a file it might look empty but please scroll down and verify entries are available.

• Export entries from oud2 using ldapsearch

ldapsearch -h <oud2_hostName> -p <Port> -D "cn=Directory Manager" -j <password_file> -b "dc=base,dc=com" "objectclass=*" dn | sort > oud2_entries.txt

Sample:-(oud2_entries.txt):-
dc=com
dc=base,dc=com
dn: cn=group1,ou=users,dc=base,dc=com
dn:.....
dn:.....
dn: cn=Test User1,ou=users,dc=base,dc=com
dn:.....
dn:.....

P.S: When you open a file it might look empty but please scroll down and verify entries are available.

• Compare two files from oud1 and oud2

Use below command to diff to compare the files and write the missing entries into a file.

diff oud1_entries.txt oud2_entries.txt > missing_entries.txt

Sample:-(missing_entries.txt):-
dn: cn=group2,ou=users,dc=base,dc=com
dn:.....
dn:.....
dn: cn=Test User2,ou=users,dc=base,dc=com
dn:.....
dn:.....

Use grep or other tools to remove first two lines (dn:) in missing_entries.txt and sample file should looks like below.

Sample:-(missing_entries.txt):-
cn=group2,ou=users,dc=base,dc=com
cn=....
cn=Test User2,ou=users,dc=base,dc=com
cn=....

• Export ldif data (with attributes) from oud1 for the missing entires. 

create export_missing_dn.sh file and update the content with below.

cat missing_entries.txt | while read LINE
do
echo "Processing $LINE" <oud_instance>/bin/ldapsearch -h <oud1_hostname> -p <port> -D "cn=Directory Manager" -j <password_file> -b "$LINE" -s base "objectclass=*" dn "*" + >> export_missing_dns.ldif
done

Run export_missing_dn.sh, it should create a file with name, export_missing_dns.ldif. Open the file and make sure there format of ldif is correct before importing.

• Import the ldif into oud2 

Import the ldif into oud2 using ldapmodify

ldapmodify -J 1.3.6.1.4.1.26027.1.5.2 -h <oud2_hostname> -p <port> -D "cn=Directory Manager" -j <pwd_file> -f export_missing_dns.ldif

That's all. Now your instances are in sync..

Thank you for visiting.