In this part, we’ll go over how to set up a directory server replica, or a second Directory Server running in a Master/Slave configuration, which comes in handy when the demand on the primary Directory Server is consistently high.

under fact, under this setup, the Master Directory Server will continue to be the authoritative source for keeping and maintaining both user data and server configuration, but it will forward any requests from the other infrastructure nodes to the Replica. As a result, if data is updated on the master, a copy is immediately sent to the slave and made searchable. The two servers will share their workloads, which will ultimately decrease the stress on the primary instance.

Preliminaries

Please carefully study the whole installation guide on this page before attempting to install a Directory Server Replica and confirm that the following conditions are met.

The rest of this section demonstrates how to deploy one Replica on a dedicated node, while it can also be installed on an existing cluster node.

• Already, a Multi-Server Carbonio is functioning properly.
• The Replica can be installed on a new node that meets the Multi Server Requirements and on which the Preliminary Tasks have previously been completed. This node will be known as SRV7.
• Every command, with the exception of the one in the Installation section, must be run as the zextras user.
• Give the new node a name or FQDN that has meaning. When applicable, we shall utilise ds-replica.example.com. Don’t forget to substitute the name you provide.
• You need to run commands on both the Main and Replica Directory Servers, thus you need have CLI access to both servers.

Installation

This command must be run on SRV7 in order to complete the installation.

There are a few stages involved in configuring the Replica Directory server.

Testing:

 Following a successful installation, you may do a simple test to see if the Replica is functioning properly.

1. Create a test user with a password by logging into the Master (SRV1):
2. Check that all of your accounts have been transferred from the Master by logging onto the Replica:The email address john.doe@example.com must appear in the results.
3. run the command on the replica

If everything is running well, the command’s output will resemble:

Create a replica to respond to inquiries

It is now necessary to change the value of the ldap_url argument so that it points to the Replica in order to set up the Replica to respond to queries instead of the Master. A few commands on the Master will get you to this configuration.

1. Put an end to all Carbonio services
2. Change the ldap_url value

If you want to set up several Replica Directory Servers, you may do so by installing each one separately and then running the aforementioned command once for each Replica, ensuring sure that their hostnames come before the Master’s hostname. Execute, for instance, the command mentioned first, The Replica instance to query first is the first stated in the command, assuming you deployed two Replica Directory Servers on SRV4 and SRV5.

Get rid of a replica

Two actions must be taken in order to delete a Replica:

Run the following command on each node of the Multiple-Server installation to limit queries to the Master.

The aforementioned command will send all queries to the Master if you had configured several Replicas. Simply exclude its hostname from the list if you only want to get rid of certain of the Replicas. For instance, execute the command to get rid of SRV5.

Execute the command solely on the MTA node.

Using the updated ldap_url, this command will update postfix’s settings.