Migrating from a single-node deployment to a three-node deployment

To your existing single-node cluster, add two more hosts of the same platform and operating system as the current host.

• See Supported platforms and operating systems.

• See Multi-node cluster hardware requirements. Your current host is used as node0 (instana-0) in the multi-node cluster.

• See CPU and memory requirements.

Then, complete the migration by following these steps:

1. On all the three hosts, make sure that the ports are open.

2. On all the three hosts, configure private IP addresses.

3. On the two new hosts, make sure to check the Kernel parameters.

4. On the two new hosts, check the required packages and environment variables.

5. On all the three nodes, configure Secure Shell.

6. Shut down Self-Hosted Standard Edition on the current host.

   stanctl down
    

   Attention:

   Self-Hosted Standard Edition 1.10.3 and earlier versions:

   • For online (non–air‑gapped) installations, most stanctl lifecycle commands, such as stanctl up will fail to run.
   • For air‑gapped installations, the stanctl commands continue to work.

   Required action: Upgrade stanctl to 1.10.4 or later versions before you perform a lifecycle operation.

   Example: On online deployments that run stanctl 1.10.3 or earlier versions, any workflow that stops services, such as a stanctl down command, before a backup, cannot complete because the subsequent stanctl up command fails. Upgrade stanctl to 1.10.4 or later versions before you start these steps.

For more information about how the storage directories are used in a multi-node cluster, see Storage requirements.

Note: If your hosts are deployed in a cloud environment, follow the instructions that are provided by the cloud provider for mounting and unmounting the paths. For example, for AWS EC2, see Amazon EBS volume lifecycle

.

During migration, you unmount three disks from your old host and then mount them on your new host (node1 (instana-1).

The following example steps are for unmounting and mounting the paths in a non-cloud environment.

1. On the old host (node0 (instana-0)), unmount the data, analytics, and metrics paths.

   umount /mnt/instana/stanctl/analytics
   umount /mnt/instana/stanctl/metrics
   umount /mnt/instana/stanctl/data

2. Detach the three disks from the old host (node0 (instana-0)).

3. Update fstab entry.

    sudo cp /etc/fstab /etc/fstab.bak
      for folder in analytics metrics data; do 
        sudo sed -i "/^[[:space:]]*#/! {/[^[:space:]]*\/${folder}[[:space:]]/ s|^|# |}" /etc/fstab
      done

4. On the new host node1 (instana-1), complete the following steps:

   1. Add the three disks from (node0 (instana-0)).
   2. Create the data, analytics, and metrics directories. For more information, see Create the directories.
   3. Mount the data, analytics, and metrics paths on node1 (instana-1). See the commands for node1 (instana-1) in Add mount paths.
   4. Complete the steps on node1 (instana-1) as given in sections Verify the mount paths and Mount the file systems.

On node0 (instana-0), run the following command to start the migration:

stanctl up --multi-node-migrate
 

Enter the details at the prompts:

? Enter the IPs for all three nodes, separated by commas (the 1st one is for backend, the 2nd one is for datastore, e.g. 10.8.1.10,10.8.1.11,10.8.1.12):
 

After a few minutes, your data is migrated to the new hosts. Standard Edition is now deployed on the multi-node cluster.