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Note:

The Active/Active Disaster Recovery installation requires two High Availability Add-on licenses.

Configuring DNS entries

Before installing HAA, you must define your domain using DNS. You must create an A Record for each of the six (or more) Linux servers where you plan to install HAA. At least three servers are required for each of the two datacenter sites. All the A Records associated with a datacenter must correspond to an NS Record.

To configure the DNS entries, take the following steps:

1. Make sure the cluster and at least one node (preferably all nodes) in the cluster are correctly configured in the DNS with the appropriate NS entries.
   For example:
   • Your domain is: mydomain.com
   • You would like to name the HAA cluster mycluster
   • You have three nodes in the cluster:
     • node1 (IP address 1.1.1.1)
     • node2 (2.2.2.2)
     • node3 (3.3.3.3)
2. In the FQDN field, enter the mycluster.mydomain.com value, and add the following records in the DNS table for mydomain.com:

mycluster.mydomain.com        NS  node1.mycluster.mydomain.com
                                  node2.mycluster.mydomain.com
                                  node3.mycluster.mydomain.com 

node1.mycluster.mydomain.com  A   1.1.1.1

node2.mycluster.mydomain.com  A   2.2.2.2

node3.mycluster.mydomain.com  A   3.3.3.3

HAA CRDB setup

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Important!

If you already have HAA installed, make sure to uninstall it from all servers before proceeding. Use the following command: sudo ./rl_uninstall.sh.

Installing HAA nodes

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Important!

Before proceeding with the HAA installation, make sure all your nodes meet the prerequisites.

Take the following steps on all the nodes in both datacenters:

1. SSH the primary node with root permissions.
2. Create a directory where you plan to download and extract HAA. For example:

mkdir haa

2. Change to the newly created directory:

cd/<path-to>/haa/

3. Download haa.tar.gz:

wget https://download.uipath.com/haa/2022.4.0/$OS/haa-2022.4.0.tar.gz

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Note:

Use $OS to specify the operating system running on the node. Possible values are: Rhel7, Rhel8, Ubuntu. Keep in mind that the values are case-sensitive.

4. Unzip the haa.tar.gz archive:

tar -xvf haa-2022.4.0.tar.gz

5. Make install-haa.sh executable:

chmod a+x install-haa.sh

6. Run the install-haa.sh script:

./install-haa.sh -y

Creating and configuring the clusters

To create a cluster, take the following steps on all the nodes in the datacenter:

1. Using your browser, navigate to the IP address of any HAA node on port 8443. For example: https://10.10.20.196:8443/.

2. Click Setup. The node configuration page is displayed.

3. In the Cluster configuration section, select Create new cluster and provide one of the previously created NS Records in the Cluster name (FQDN) field. Optionally, you can change the persistent or ephemeral storage path, choose from multiple network adapters, etc. Click Next when you are done. The cluster authentication page is displayed.

4. In the Cluster key field, provide a license key if you have one, and click Next:

5. On the set admin credentials page, provide an email address and a password, and click Next

6. The cluster has been created. You should now see the UI for High Availability Add-On for Orchestrator.

7. Take the same steps on all the other nodes in the cluster. On the node configuration page, in the Cluster configuration section, you must select Join cluster instead of Create new cluster and also provide the following:

   • IP address of a node in the cluster - provide the IP address of the node you have previously added to the cluster
   • Email - the email you used to create the cluster
   • Password - the password you used to create the cluster

Creating a geo-distributed database

To create geo-distributed databases, take the following steps:

1. From the HAA application on the Primary Datacenter, click the databases tab.
2. From the create new database window, select Geo-Distributed under the drop-down for Deployment and click Next.

3. On the create database page, enter the following information:
   • Name: uipath-orchestrator
   • Memory limit (GB): 3 GB
   • Replication: Checked
   • Redis password: the HAA database password.
   • Database Clustering: Unchecked
   • Endpoint port number: 10000
   • Participating clusters: Click + to add each participating cluster, using the Cluster API URL https://<DNS delegation cluster name>:9443and admin credentials for the primary and secondary datacenters, respectively.

4. Click Activate.

After activation is complete, the time primary datacenter HAA application's Databases displays an active Redis CRDB database with a green Sync symbol under Status to indicate enabling of the database sync on the Primary Datacenter.

Configuring UiPath.Orchestrator.dll.config

From the primary datacenter HAA application:

1. Open the databases tab and click configuration.

2. Copy the endpoint before the backslash and apply to the UiPath.Orchestrator.dll.config file for the primary datacenter Orchestrator.

For the secondary datacenter:

1. Open the Databases tab and click Configuration.
2. Copy the Endpoint before the backslash and apply to the UiPath.Orchestrator.dll.config file for the secondary datacenter Orchestrator.