Quickstart: Configure a hybrid cluster with Azure Managed Instance for Apache Cassandra by using the Client Configurator

The Azure Client Configurator is a tool designed to assist you in configuring a hybrid cluster and simplifying the migration process to Azure Managed Instance for Apache Cassandra. If you currently have on-premises datacenters or are operating in a self-hosted environment, you can use Azure Managed Instance for Apache Cassandra to seamlessly incorporate other datacenters into your cluster while effectively maintaining them.

Prerequisites

• Use the Bash environment in Azure Cloud Shell. For more information, see Get started with Azure Cloud Shell.

  

• If you prefer to run CLI reference commands locally, install the Azure CLI. If you're running on Windows or macOS, consider running Azure CLI in a Docker container. For more information, see How to run the Azure CLI in a Docker container.

  • If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For other sign-in options, see Authenticate to Azure using Azure CLI.

  • When you're prompted, install the Azure CLI extension on first use. For more information about extensions, see Use and manage extensions with the Azure CLI.

  • Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

• This article requires the Azure CLI version 2.30.0 or later. If you're using Azure Cloud Shell, the latest version is already installed.

• Use an Azure virtual network with connectivity to your self-hosted or on-premises environment. For more information on how to connect on-premises environments to Azure, see Connect an on-premises network to Azure.

• A Python installation is required. To check if Python is installed, run python --version in your terminal.

• Ensure that both the Azure Managed Instance for Apache Cassandra cluster and the on-premises Cassandra cluster are located on the same virtual network. If not, you need to establish network peering or another means of connectivity. For example, use Azure ExpressRoute.

• The cluster name for both the managed cluster and local cluster must be the same.

  In the cassandra.yaml file, ensure that the storage port is set to 7001 and the cluster name is the same as the managed cluster:

  cluster_name: managed_cluster-name
  storage_port: 7001
  

  UPDATE system.local SET cluster_name = 'managed_cluster-name' where key='local';
  

Installation

1. Download and go into the client configurator folder.

2. Set up a virtual environment to run the Python script:

   python3 -m venv env
   source env/bin/activate
   python3 -m pip install -r requirements.txt
   

3. Sign in to the Azure CLI az login.

4. Run the Python script within the client folder with information from the existing (on-premises) cluster:

   python3 client_configurator.py --subscription-id <subcriptionId> --cluster-resource-group <clusterResourceGroup> --cluster-name <clusterName> --initial-password <initialPassword> --vnet-resource-group <vnetResourceGroup> --vnet-name <vnetName> --subnet-name <subnetName> --location <location> --seed-nodes <seed1 seed2 seed3> --mi-dc-name <managedInstanceDataCenterName> --dc-name <onPremDataCenterName> --sku <sku>
   

   Parameter	Description
   subscription-ID	Azure subscription ID
   cluster-resource-group	Resource group where your cluster resides
   cluster-name	Azure Managed Instance for Apache Cassandra cluster name
   initial-password	Password for your Azure Managed Instance for Apache Cassandra cluster
   vnet-resource-group	Resource group attached to the virtual network
   vnet-name	Name of the virtual network attached to your cluster
   subnet-name	Name of the IP addressed allocated to the Cassandra cluster
   location	Where your cluster is deployed
   seed-nodes	Seed nodes of the existing datacenters in your on-premises or self-hosted Cassandra cluster
   mi-dc-name	Datacenter name of your Azure Managed Instance for Apache Cassandra cluster
   dc-name	Datacenter name of the on-premises cluster
   sku	Virtual machine product tier size

5. The Python script produces a tar archive named install_certs.tar.gz. Unpack this folder into /etc/cassandra/ on each node:

   sudo tar -xzvf install_certs.tar.gz -C /etc/cassandra
   

6. Inside the /etc/cassandra/ folder, run sudo ./install_certs.sh.

   • Ensure that the script is executable by running sudo chmod +x install_certs.sh.

   • The script installs and points Cassandra toward the new certificates that are needed to connect to the Azure Managed Instance for Apache Cassandra cluster.

   • It then prompts the user to restart Cassandra.

     

7. After Cassandra is finished restarting on all nodes, check nodetool status. Both datacenters should appear in the list, with their nodes in the UN (Up/Normal) state.

8. From your instance of Azure Managed Instance for Apache Cassandra, you can then select AllKeyspaces to change the replication settings in your keyspace schema and start the migration process to the Azure Managed Instance for Cassandra cluster.

9. Enable the autoReplicate setting by using an Azure Resource Manager template (ARM template). The ARM template should include:

   "properties":{
   ...
   "externalDataCenters": ["dc-name-1","dc-name-2"],
   "autoReplicate": "AllKeyspaces",
   ...
   }
   

   All of your keyspaces definitions change to include WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'on-prem-datacenter-1' : 3, 'mi-datacenter-1': 3 }. If this topology isn't what you want, adjust it and run nodetool rebuild manually on the Azure Managed Instance for Apache Cassandra cluster.

   Learn more about autoreplication.

10. Update and monitor data replication progress by selecting the Data Center pane.

    

Next step