Add a backend server in a legacy architecture

Expanding a cluster in a legacy architecture with a new backend server is similar to the WEKA legacy system installation process.

Adding a server to the cluster includes adding the containers and configuring the networking, CPU resources, and SSDs.

Adding a server to the cluster in a legacy architecture

Note: In most cases, the container configurations are similar. Therefore, importing the container settings from a previously exported container in the cluster is possible, saving time and avoiding misconfiguration. See Expand the cluster by importing the server settings.

Add a backend server to an existing cluster

1. Obtain the WEKA install file.

   • Download the WEKA install file used when the existing cluster was last upgraded (or formed, if not upgraded). See Obtain the WEKA software installation package.

   • Use the weka status command to show the current cluster install file version.

2. Install the WEKA software on the new server.

   • Run the untar command and install.sh command on the new server. At the end of the installation process, the server is in stem mode (the server is not attached to a cluster).

3. Add the container to the cluster.

   • Run the following command line on any container in the cluster. In the backend-hostname property, specify the IP address or hostname of the new backend server to add.

weka cluster container add <backend-hostname>

Note: Once this step is completed, the container ID of the newly added server appears in response to the command. Make a note of it to use in the following steps.

4. Configure the networking.

   • Perform the instructions in #stage-6-configure-the-networking.
5. Configure the CPU resources.

   • Perform the instructions in #stage-8-configure-the-cpu-resources.
6. Apply the configuration of the container on the newly added server.

   • Perform the instructions in Stage 13: Apply containers configuration.

Note: You can activate the cluster containers sequentially.

7. Configure the SSDs.

   • Perform the instructions in #7.-configure-the-ssds.

Expand the cluster by importing the container settings

In most cases, the server configurations are similar. Therefore, importing the server setting from a previously exported server in the cluster is possible, saving time and avoiding misconfiguration.

Procedure:

1. Perform only steps 1 to 3 in the Add a backend server to an existing cluster procedure (above).

2. Connect to one of the servers in the cluster and export the settings by running the following command: weka local resources export.

3. Connect to the new server and import the settings by running the following command: weka local resources import.

4. Edit the local configuration.

   • See the #local-resources-editing-commands section.
5. Apply the configuration on the newly added server.

   • See Stage 13: Apply containers configuration.