Red Hat SummitChapter 3. Cluster Expansion
To expand an existing Gluster cluster already imported and managed by the Web Administration environment, perform the following sequence of actions:
- Unmanage the existing cluster from Web Administration.
- Expand the Gluster storage nodes.
- Install the Web Administration components via tendrl-ansible.
- Reimport the cluster in the Web Administration environment.
3.1. Unmanaging Cluster
For all the clusters that are currently managed by Web Administration, un-managing one cluster will result in all the clusters being un-managed. You will have to re-import any cluster that is required.
Unmanage a cluster from Web Administration
-
Stop and uninstall all
tendrl-*services andCollectdon the storage nodes monitored by Web Administration. See Commands for Stopping Tendrl Services section for the commands required to stop the services. - Stop all tendrl-* and related services like Grafana or Graphite on Tendrl server. See Commands for Stopping Tendrl Services section for the commands required to stop the services.
- Backup and delete data directories from the Web Administration server for Graphite and Carbon services to ensure stale metrics do not persist. See Commands for Deleting Database Files section for the commands required to remove database files.
Backup and uninstall Etcd from Web Administration server and delete all data from etcd. See Commands for Deleting Database Files section for the commands required to remove database files.
NoteDelete the etcd
%data_dirfrom all members of the etcd cluster. For more details, see Data Directory Lifecycle documentation.
3.1.1. Commands for Stopping Tendrl Services
Stopping Services on Storage Nodes
Run the following commands to stop individual services on the Storage Nodes:
To stop the tendrl-node-agent service:
# service tendrl-node-agent stop
To stop the collectd service:
# service collectd stop
To stop the tendrl-gluster-integration service:
# service tendrl-gluster-integration stop
Stopping services on Tendrl server
Run the following commands to stop individual services on the Tendrl server.
To stop the etcd service:
# service etcd stop
To stop the tendrl-monitoring-integration service:
# service tendrl-monitoring-integration stop
To stop the tendrl-api service:
# service tendrl-api stop
To stop the tendrl-notifier service:
# service tendrl-notifier stop
To stop the carbon-cache service:
# service carbon-cache stop
To stop the grafana-server service:
# service grafana-server stop
To stop the tendrl-node-agent service:
# service tendrl-node-agent stop
3.1.2. Commands for Deleting Database Files
The default paths mentioned here are for Etcd, Carbon and Grafana and are not for Tendrl services. The data_dir can be set to any directory as part of their configuration. Please ensure to remove the data_dir from the correct path.
Commands for Removing the database files from Server Node:
To remove Etcd files:
# rm -rf /var/lib/etcd/*
To remove Carbon files which will remove the monitoring data:
# rm -rf /var/lib/carbon/whisper/*
To remove Grafana files:
# rm -rf /var/lib/grafana/grafana.db
3.2. Expanding Storage Nodes
To expand the cluster, see the Expanding Volumes section in the Red Hat Gluster Storage Administration Guide.
- After the cluster is expanded, install Web Administration. For detailed intallation instructions, see the Installing Web Administration chapter in the Red Hat Gluster Storage Web Administration Quick Start Guide.
Start the following services on the Storage nodes:
To start the tendrl-node-agent service:
# service tendrl-node-agent start
To start the collectd service:
# service collectd start
3.3. Reimporting Cluster
Once the services are started, import the cluster in Web Administration. For instructions on importing cluster, see the Import Cluster chapter of this Guide.
