Stages in Adding a Backend Host

The page describes the expansion of a cluster with new hosts, which is similar to the WekaIO System Installation Process Using the CLI and consists of the following stages.

Stage 1: Obtaining the WekaIO Install File

This stage is the same as Obtaining the WekaIO Install File. However, it is essential to download the install file used when the existing cluster was formed or last upgraded. Use the weka-status command to show the current cluster install file version.

To download the appropriate install file, follow the instructions in Download the WekaIO Software.

Stage 2: Installing the WekaIO Software on the New Host

Follow the instructions appearing in Installation of the WekaIO Software on Each Host. At the end of the install process the host is in stem mode.

Stage 3: Adding a Host to the Cluster

Command: cluster host add

Once the backend host is in the stem mode, use the following command line on any host to add it to the cluster:

weka -H <existing-backend-hostname> cluster host add <backend-hostname>

Parameters in Command Line

Name

Type

Value

Limitations

Mandatory

Default

existing-backend-hostname

String

IP/host name of one of the existing backend instances in the cluster

Valid host name (DNS or IP)

No

The host on which the command is executed

backend-hostname

String

IP/host name of the backend currently being added

Valid host name (DNS or IP)

Yes

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Note: On completion of this stage, the host-ID of the newly added host will be received. Make a note of it for the next steps.

Stage 4: Configuration of Networking

Follow the instructions appearing in Configuration of Networking.

Note: The networking technology has to be the same as the existing networking technology in the cluster, i.e., it is not possible to mix Ethernet and IB technologies.

Stage 5: Configuration of SSDs

Follow the instructions appearing in Configuration of SSDs.

Stage 6: Scanning Drives

Follow the instructions appearing in Scanning Drives.

Stage 7: Configuration of CPU Resources

Follow the instructions appearing in Configuration of CPU Resources.

Stage 8: Configuration of Memory

Use the following command line to display a listing of the memory defined (one line for each host):

weka cluster host

To configure the memory, follow the instructions appearing in Configuration of Memory.

Note: If memory has been configured, it is mandatory to use the same memory for the expanded host.

Stage 9: Configuration of Failure Domains

Follow the instructions appearing in Configuration of Failure Domains.

Note: Plan whether each host is being added to an existing failure domain or to a new failure domain.

Stage 10: Activation of Cluster Hosts

If hosts have been added to the cluster, follow the instructions appearing in Activation of Cluster Hosts.

Note: The activation of cluster hosts can be performed with a sequence of hosts.

Stage 11: Activation of Cluster SSDs

If SSDs have been added to the cluster, follow the instructions appearing in Activation of Cluster SSDs.