Specifications

76 | august 2008 www.linuxjournal.com
INDEPTH
no schedule is specified (the default), the rule runs all the time.
In our rule, only one user will be notified. You also can create
groups of users from the Settings page, so that multiple people
are alerted, or you could use a group e-mail address in your
user properties.
Figure 5. Zenoss alerts are sent fresh to your mailbox.
Services and Processes
We can expand our view of the test systems by adding a
process and a service for Zenoss to monitor. When we
refer to a process in Zenoss, we mean an active program,
usually a dæmon, running on a managed device. Zenoss
uses regular expressions to monitor processes.
To monitor Postfix on the mail server, first, let’s define
it as a process. Navigate to the Processes page under the
Classes section of the navigation menu. Use the drop-
down arrow next to OS Processes, and click Add Process.
Enter Postfix as the process ID. When you return to the
previous page, click on the link to the new process. On the
edit tab of the process, enter
master in the Regex field.
Click Save before navigating away. Go to the zProperties
tab of the process, and make sure the zMonitor field is set
to True. Click Save again. Navigate back to the mail server
from the dashboard, and on the OS tab, use the topmost
menu’s drop-down arrow to select Add→Add OSProcess.
After the process has been added, we will be alerted if the
Postfix process degrades or fails. While still on the OS tab
of the server, place a check mark next to the new Postifx
process, and from the OS Processes drop-down menu,
select Lock OSProcess. On the next set of options, select
Lock from deletion. This protects the process from being
overwritten if Zenoss remodels the server.
Services in Zenoss are defined by active network ports
instead of running dæmons. There are a plethora of ser-
vices built in to the software, and you can define your own
if you want to. The built-in services are broken down into
two categories: IPServices and WinServices. IPServices use
any port from 1-65535 and include common network
apps/protocols, such as SMTP (Port 25), DNS (53) and HTTP
(80). WinServices are intended for specific use with
Windows servers (Figure 6).
Adding a service is much simpler than adding a process,
because there are so many predefined in Zenoss. To moni-
tor the HTTP service on our Web server, navigate to the
server from the dashboard. Use the main menu’s drop-
down arrow on the server’s OS tab arrow, and select
Add→Add IPService. Type
HTTP in the Service Class Field.
Notice that the field begins to prefill with matches as you
Using a filter, you can create any
number of rules and have them
apply only to specific devices or
groups of devices.
Figure 7. Monitoring HTTP as an IPService
Figure 6. Zenoss comes with a plethora of predefined Windows services
to monitor.