Monitoring is provided for Linux servers through the collectd agent. Collectd is an actively developed, feature rich, mature and lightweight monitoring agent, written in C for performance and portability. It is also open source, which means that no proprietary blobs will be installed on your servers.
There are two ways to enable monitoring in ClearGLASS. The easiest way is to provide SSH access to your server. If SSH acess is not possible or desirable, you can choose to manually install the collectd monitoring agent.
ClearGLASS needs to connect to your servers using SSH in order to set up monitoring and enable the web, touch-friendly console. Head over to the keys section and click on the Add button to set up your keypairs. If you already have a private SSH key that you use to connect to the server, you can import it in ClearGLASS by pasting your private key on the text dialog or by uploading the key file. Otherwise, you can generate a new SSH key through ClearGLASS and copy the public key to your server. Once you have a keypair set up, ClearGLASS can deploy it automatically on any new servers created through the service.
Once your server is connectable by ClearGLASS, you’ll see a blue bar appearing next to it on your machine list, indicating your server’s load. Click on the machine to go to the detailed view and then on the Enable button in the Monitoring section. ClearGLASS will then install the collectd open source agent and you'll start seeing the monitoring graphs once it is done.
Once monitoring is enabled, you should start seeing graphs with monitoring data. Click on the Add Rule button just below the graph to set up your first alerting rule. E.g. if you want to get an email once the load exceeds 4, your rule should look like this:
For example, if you have a process that’s leaking memory, you can set up ClearGLASS to restart that process once your memory usage exceeds 95%.
That’s it. You’ve successfully set up monitoring for your server and added your first alerting rules.
<note>If ClearGLASS is running on a server with a self-signed certificate, you will need to import its CA certificate onto the machines you are monitoring before starting the monitoring agent. See Trusting the Certificate Authority of ClearOS in Servers and Workstations for details.</note>