Monitoring¶

Monitoring in Zentyal¶

The monitor module allows the administrator to view the status of system resources from the Zentyal server. This information is essential to assist with both troubleshooting and advanced planning of resources in order to avoid problems.

Monitoring is displayed using graphics which give a quick overview of resource usage trends. You can see the graphical monitor by viewing the menuselection:Monitor module. Placing the cursor somewhere over the line on the graph you are interested in, the exact value for a given instant can be determined.

You can choose the time scale of the graphs to view an hour, a day, month or year. To do this, simply click on the tab you are interested in.

Tabs with the different monitoring reports

Metrics¶

System load¶

The system load attempts to measure the rate of pending work over the completed work. This metric is defined as the number of runnable tasks in the run-queue and is provided by many operating systems as a one, five or fifteen minutes average.

System load graphic

CPU usage¶

This graph shows detailed information of the CPU usage. For multi-core or multi-cpu machines you will see one graph for each core.

These graphs represent the amount of time that the CPU spends in each of its states: running user code, system code, inactive, input/output wait, and so on. The time is not a percentage, but scheduling units known as jiffies. In most Linux systems this value is 100 per second, but this may differ.

CPU usage graph

Memory usage¶

This graph displays the memory usage. The following variables are monitored:

Free memory:

Amount of memory not used

Page cache:

Amount of memory that is cached in a disk swap

Buffer cache:

Amount of memory that is cached for input/output operations

Memory used:

Amount of memory that is not included in any of the above

Memory usage graphic

File system usage¶

This graph displays the used and free space of every mount point.

File system usage graphic

Temperature¶

This graph allows you to view the system temperature in Celsius degrees by using the ACPI system [1]. In order to enable this metric, the server must have this system installed and the kernel must support it.

[1]	Advanced Configuration and Power Interface (ACPI) is an open standard to configure devices focused on operating systems and power management. http://www.acpi.info/

Temperature sensor diagram graphic

Alerts¶

The monitoring system would be largely unused if it was not coupled with a notification system to warn users when uncommon values are produced. This ensures that you know when the host is suffering from an unusual load or is nearing maximum capacity.

Monitoring alerts are configured in Events module. Go to Events ‣ Configure Events; here you can see the full list of available alerts, the relevant events are grouped in the Monitor event.

Configuration screen for the monitor observers

Clicking on the cell configuration, you access the event configuration. You can choose any of the monitored metrics and establish thresholds which trigger events.

Configuration screen for event thresholds

There are two different thresholds, warning and failure, this allows the user to filter events based on severity. You can use the option reverse: to swap the values that are considered right and wrong. Other important option is persistent:. Depending on the metric you can also set other parameters, for instance, you may receive alerts for the free space in hard disk metric, or the short term load in system load metric and so on.

Each measure has a metric that is described as follows:

System load:

The values must be set in average number of runnable tasks in the run-queue.

CPU usage:

The values must be set in jiffies or units of scheduling.

Physical memory usage:

The values must be set in bytes.

File system:

The values must be set in bytes.

Temperature:

The values must be set in degrees.

Once you have configured and enabled the event at least one observer must also be configured. The observer configuration is the same as the configuration of any other event. Check the Events and alerts chapter for more information.