2.2. Migrating the Data Warehouse Service to a Separate Machine

You can migrate the Data Warehouse service installed and configured on the Red Hat Virtualization Manager to a separate machine. Hosting the Data Warehouse service on a separate machine helps to reduce the load on the Manager machine.

Notice that this procedure migrates the Data Warehouse service only.

To migrate the Data Warehouse database (ovirt_engine_history) prior to migrating the Data Warehouse service, see Migrating the Data Warehouse Database to a Separate Machine.

Note

Red Hat only supports installing the Data Warehouse database, the Data Warehouse service and Grafana all on the same machine as each other, even though you can install each of these components on separate machines from each other.

Prerequisites

  • You must have installed and configured the Manager and Data Warehouse on the same machine.
  • To set up the new Data Warehouse machine, you must have the following:

    • The password from the Manager’s /etc/ovirt-engine/engine.conf.d/10-setup-database.conf file.
    • Allowed access from the Data Warehouse machine to the Manager database machine’s TCP port 5432.
    • The username and password for the Data Warehouse database from the Manager’s /etc/ovirt-engine-dwh/ovirt-engine-dwhd.conf.d/10-setup-database.conf file.

      If you migrated the ovirt_engine_history database using the procedures described in Migrating the Data Warehouse Database to a Separate Machine, the backup includes these credentials, which you defined during the database setup on that machine.

Installing this scenario requires four steps:

  1. Setting up the New Data Warehouse Machine
  2. Stopping the Data Warehouse service on the Manager machine
  3. Configuring the new Data Warehouse machine
  4. Disabling the Data Warehouse package on the Manager machine

2.2.1. Setting up the New Data Warehouse Machine

Enable the Red Hat Virtualization repositories and install the Data Warehouse setup package on a Red Hat Enterprise Linux 8 machine:

  1. Enable the required repositories:

    1. Register your system with the Content Delivery Network, entering your Customer Portal user name and password when prompted:

      # subscription-manager register
    2. Find the Red Hat Virtualization Manager subscription pool and record the pool ID:

      # subscription-manager list --available
    3. Use the pool ID to attach the subscription to the system:

      # subscription-manager attach --pool=pool_id
    4. Configure the repositories:

      # subscription-manager repos \
          --disable='*' \
          --enable=rhel-8-for-x86_64-baseos-eus-rpms \
          --enable=rhel-8-for-x86_64-appstream-eus-rpms
          --enable=rhv-4.4-manager-for-rhel-8-x86_64-rpms \
          --enable=fast-datapath-for-rhel-8-x86_64-rpms \
          --enable=jb-eap-7.4-for-rhel-8-x86_64-rpms
      
      # subscription-manager release --set=8.6
  2. Enable the pki-deps module.

    # dnf module -y enable pki-deps
  3. Ensure that all packages currently installed are up to date:

    # dnf upgrade --nobest
  4. Install the ovirt-engine-dwh-setup package:

    # dnf install ovirt-engine-dwh-setup

2.2.2. Stopping the Data Warehouse Service on the Manager Machine

Procedure

  1. Stop the Data Warehouse service:

    # systemctl stop ovirt-engine-dwhd.service
  2. If the database is hosted on a remote machine, you must manually grant access by editing the postgres.conf file. Edit the /var/lib/pgsql/data/postgresql.conf file and modify the listen_addresses line so that it matches the following:

    listen_addresses = '*'

    If the line does not exist or has been commented out, add it manually.

    If the database is hosted on the Manager machine and was configured during a clean setup of the Red Hat Virtualization Manager, access is granted by default.

  3. Restart the postgresql service:

    # systemctl restart postgresql

2.2.3. Configuring the New Data Warehouse Machine

The order of the options or settings shown in this section may differ depending on your environment.

  1. If you are migrating both the ovirt_engine_history database and the Data Warehouse service to the same machine, run the following, otherwise proceed to the next step.

    # sed -i '/^ENGINE_DB_/d' \
            /etc/ovirt-engine-dwh/ovirt-engine-dwhd.conf.d/10-setup-database.conf
    
    # sed -i \
         -e 's;^\(OVESETUP_ENGINE_CORE/enable=bool\):True;\1:False;' \
         -e '/^OVESETUP_CONFIG\/fqdn/d' \
         /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf
  2. Run the engine-setup command to begin configuration of Data Warehouse on the machine:

    # engine-setup
  3. Press Enter to accept the automatically detected host name, or enter an alternative host name and press Enter:

    Host fully qualified DNS name of this server [autodetected host name]:
  4. Press Enter to automatically configure the firewall, or type No and press Enter to maintain existing settings:

    Setup can automatically configure the firewall on this system.
    Note: automatic configuration of the firewall may overwrite current settings.
    Do you want Setup to configure the firewall? (Yes, No) [Yes]:

    If you choose to automatically configure the firewall, and no firewall managers are active, you are prompted to select your chosen firewall manager from a list of supported options. Type the name of the firewall manager and press Enter. This applies even in cases where only one option is listed.

  5. Enter the fully qualified domain name and password for the Manager. Press Enter to accept the default values in each other field:

    Host fully qualified DNS name of the engine server []: engine-fqdn
    Setup needs to do some actions on the remote engine server. Either automatically, using ssh as root to access it, or you will be prompted to manually perform each such action.
    Please choose one of the following:
    1 - Access remote engine server using ssh as root
    2 - Perform each action manually, use files to copy content around
    (1, 2) [1]:
    ssh port on remote engine server [22]:
    root password on remote engine server engine-fqdn: password
  6. Enter the FQDN and password for the Manager database machine. Press Enter to accept the default values in each other field:

    Engine database host []: manager-db-fqdn
    Engine database port [5432]:
    Engine database secured connection (Yes, No) [No]:
    Engine database name [engine]:
    Engine database user [engine]:
    Engine database password: password
  7. Confirm your installation settings:

    Please confirm installation settings (OK, Cancel) [OK]:

The Data Warehouse service is now configured on the remote machine. Proceed to disable the Data Warehouse service on the Manager machine.

Note

If you want to change the Data Warehouse sampling scale to the recommended scale on a remote server, see Changing the Data Warehouse Sampling Scale.

2.2.4. Disabling the Data Warehouse Service on the Manager Machine

Procedure

  1. On the Manager machine, restart the Manager:

    # service ovirt-engine restart
  2. Run the following command to modify the file /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf and set the options to False:

    # sed -i \
         -e 's;^\(OVESETUP_DWH_CORE/enable=bool\):True;\1:False;' \
         -e 's;^\(OVESETUP_DWH_CONFIG/remoteEngineConfigured=bool\):True;\1:False;' \
         /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf
    
    # sed -i \
         -e 's;^\(OVESETUP_GRAFANA_CORE/enable=bool\):True;\1:False;' \
         /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf
  3. Disable the Data Warehouse service:

    # systemctl disable ovirt-engine-dwhd.service
  4. Remove the Data Warehouse files:

    # rm -f /etc/ovirt-engine-dwh/ovirt-engine-dwhd.conf.d/*.conf /var/lib/ovirt-engine-dwh/backups/*

The Data Warehouse service is now hosted on a separate machine from the Manager.